Europe/Prague
Casino Conference Centre

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Description
Participants
• Agata Oszczak
• AGNIESZKA FULARA
• Ainon Hamzah
• Aleksander Bilewicz
• Aleksey Troshin
• Alena Tokarova
• Alexander Kostylev
• Alexander Mansel
• Alexander Popkov
• Alexander Yakushev
• Alexey Rodin
• Alexey Safonov
• Aleš Vetešník
• Alicia Negron-Mendoza
• Amares Chatt
• Andreas Geist
• Andreas Tuerler
• Andrei Androsov
• Andrew Hodgson
• Andy King
• Anna Bajzíková
• Anna Rubailo
• Anton Fiskov
• Antonia Denkova
• Atsushi Toyoshima
• Barbara Jutta Maria Karches
• Barbora Drtinova
• Barbora Maresova
• Bayirta Egorova
• Benjamin Cvetkovic
• Bernhard Scholten
• Bert Wolterbeek
• Bogdan Wąs
• Boris Andris
• Borja Gonzalez Prieto
• Canh Hai Nguyen
• Catarina Galinha
• Celine GAUTIER
• Chris Maher
• Christian Bustillos
• Christian Ekberg
• Christian Schreinemachers
• Christian Stieghorst
• Christophe Bruggeman
• CHUAN-PIN LEE
• Claudia Landstetter
• Cory Hawkins
• Daniel Seifert
• David Chvatil
• David Teze
• Denis Glavič-Cindro
• Dmitriy Grozdov
• Dmitry Marinin
• Dusan Galanda
• Dusan Vopalka
• Edyta Łokas
• Eiliv Steinnes
• Ekaterina Kukleva
• Ekaterina Potanina
• Elena Belova
• Elena Laura Ebert
• Elena Zakharchenko
• Emilie BOSSE
• Emma Aneheim
• Ernesto Martínez Baez
• Eros Mossini
• Euo Chang Jung
• Eva Hofmanova
• Eva Juranova
• Eva Málková
• Ewa Starościak
• Ferenc Fabian
• Fernando P. Carvalho
• Frans De Corte
• Gabriela Teodorov
• Gabriela Wallova
• Gabriele Wallner
• Galina Lujaniene
• Gospodin Bozhikov
• Grazyna Przybytniak
• Grzegorz Olszewski
• Grzegorz Romanczyk
• Guozhong Wu
• Hanna Tuovinen
• Hans Vigeland Lerum
• Heino Nitsche
• Hiromitsu Haba
• Hisaaki Kudo
• Igor Izosimov
• Ilya Usoltsev
• Inga Zinicovscaia
• Ioannis Pashalidis
• Irena Spendlikova
• Irina Vlasova
• Iva Vosahlikova
• Ivan Hupka
• Ivan Kajan
• Ivana Krausova
• Ivana Milanovic
• Ivo Světlík
• Iwona Bartosiewicz
• Jakub Kuba
• Jakub Raindl
• Jakub Visnak
• James Holt
• Jan Barta
• Jan John
• Jan Kamenik
• Jan Kozempel
• Jan Krmela
• Jan Kucera
• Jan Tits
• Jana Socuvkova
• Jana Sulakova
• Janelle Droessler
• Janja Smrke
• Jaroslav Červenák
• Jenny Halleröd
• Jerzy Narbutt
• Jerzy-Wojciech Mietelski
• Jiri KOTRBA
• Jiri Landa
• Jiri Vacik
• Jitka Prajsova
• Jixin Qiao
• Jiří Janda
• Jiří Mizera
• Jon Petter Omtvedt
• Jong Myoung Lim
• JongHwa MOON
• Josef Anton
• Josef Chudoba
• Joung Hae Lee
• Juan F. Facetti-Masulli
• Judit Krajkó
• Jukka Lehto
• Julie Champion
• Jussi Ikonen
• Kamil Vavrinec Mares
• Kamila Kołacińska
• Kamila Šťastná
• Karolina Szymanska
• Katerina Videnska
• Kateřina Čubová
• Katharina Fritsch
• Katja Schmeide
• Kattesh Katti
• Kenneth Czerwinski
• Keri Campbell
• Kevin Galliez
• Kil Yong Lee
• Kirill Romachevsky
• Konstantin Dvoeglazov
• Krzysztof Borowik
• Krzysztof Kleszcz
• Kun Ho Chung
• Kwang-Rag Kim
• Leila Safavi-Tehrani
• Lenka Hrušková
• Lenka Procházková
• Leon Fuks
• Lidia Rosiak
• Lijuan Qian
• Lixin Sun
• Ljudmila Benedik
• LORANT SZATMARY
• Lucie Kománková
• Lyubomir POPOV
• Lyudmila Golovkina
• M Alkhorayef
• Magdalena Dlugosz-Lisiecka
• Magdalena Gumiela
• Magdalena Rejnis
• Marek Bystran
• Maria do Carmo Freitas
• Maria Efstathiou
• Maria Lübke
• Marina Frontasyeva
• Marja Siitari-Kauppi
• Marta Pyszynska
• Martin Cabalka
• Martin Precek
• Martin Vlk
• Martina Benesova
• Masanobu Nogami
• Masashi Murakami
• Maxim Samsonov
• Mayya Kalenova
• Melanie Müller
• Michael Krachler
• Michal Pokorný
• Michiko Fukushima
• Michio Aoyama
• Miia Lampén
• Mikhail Alyapyshev
• Milan Bunata
• Min Hoon Baik
• Ming-Chee Wu
• Mingli Zhang
• Miroslava Stilijanova
• Mojmír Němec
• Myroslav Zoriy
• Nadine Mariel Chiera
• Najat Kassim Mohammed
• Natalia Gomzina
• Natallia Torapava
• Nicholas Evans
• Nikolay Aksenov
• Nora Vajda
• Oldrich Navratil
• Oleksiy Itsenko
• Olga Gorbunova
• Olga Mokhodoeva
• Olga Shudegova
• Ondřej Lebeda
• Otilia Ana Culicov
• Pavel Bartl
• Pavel Bláha
• Pavel Bobrov
• Pavel Krist
• Pavel Povinec
• Pavol Rajec
• Peter Burns
• Peter Ivanov
• Peter Medley
• Petr Distler
• Petr Večerník
• Petr Vokac
• Petra J. Panak
• Petra Količová
• Petra Kudejova
• Petra Mičolová
• Piotr Szajerski
• Przemyslaw Kozminski
• Qiuxiang Cao
• Rajamani Natarajan
• Remi Poirot
• Rick Paul
• Robin de Kruijff
• Rolf Zeisler
• Ruveyda Kubra ILERI
• Sami Alwaer
• Sandor Takacs
• Sascha Wisser
• Semen Zavarzin
• Sergey Vinokurov
• Sergio Ramos-Bernal
• Seung Soo KIM
• Seweryn Krajewski
• Shan Xing
• Silvia Dulanská
• Sinikka Virtanen
• Sobeslav Neufuss
• Sofia Jonsson
• Stanislav ERMOLAEV
• Stefan Neumeier
• Steffen Happel
• Sukiman Sarmani
• Sung-Hee Jung
• Svetlana Tretyakova
• Svyatoslav Nikitin
• Tatiana Boytsova
• Tatiana Khaustova
• Tatiana Kuzmina
• Tatiana Livshits
• Tatiana Semenova
• Teija Koivula
• Tereza Pavelková
• Terezia Nemcova
• Thierry MENNECART
• Tibor G. Kocsor
• Timothy Payne
• Tobias Wels
• Tomas Koubsky
• Tomas Prajs
• Tomas Rosendorf
• Valeriy Luchnikov
• Valiantsina Torapava
• Vallín García Cruz
• Vanessa Sanders
• Vasiliy Babain
• Vera Mazgunova
• Veronika Kocurova
• Veronika Mocko
• Viktor Golias
• Viktoria Damberger
• Viktória Sántáné Gerse
• Vojtech Brynych
• Václav Čuba
• Václava Havlová
• Věra Bečková
• Weiqun Shi
• Wilhelm Hans EUGEN SCHWARZ
• Xiaolin Hou
• Yuichiro Nagame
• Yulia Buchatskaya
• Yulia Konevnik
• Yulia Voskresenskaya
• Yuriy Demidov
• Yutaka Miyamoto
• Zana Bikbajeva
• Zeljko Grahek
• Zsolt Révay
• Zsolt Varga
• Łukasz STECZEK
• Štěpánka Maliňáková
Support
• Sunday, May 11
• Registration Foyer

### Foyer

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Welcome drink / Opening ceremony Marble Hall

### Marble Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Hevesy Medal Award Ceremony Mirror Hall

### Mirror Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Prof. Amares Chatt (Dalhousie University), Prof. Jan John (CTU in Prague, FNSPE, Department of Nuclear Chemistry)
• 1
In the spirit of the Hevesy Award, this talk will cover selected examples of my research during the last four decades. My work has been focused on the chemistry of the actinides and the superheavy elements. I will discuss research within actinide chemistry related to solution thermodynamics of uranium, neptunium, plutonium, and americium, as well as their sorption and biological interactions with geologic matrices, for the performance assessment of potential high-level nuclear waste repositories and environmental remediation. Additionally, I will present my work on the physics and chemistry of the heaviest elements, including the confirmation of new elements, discovery of new isotopes, and one-atom-at-a-time chemistry.
Speaker: Prof. Heino Nitsche (UC Berkeley and Lawrence Berkeley National Laboratory)
• Welcome reception Marble Hall

### Marble Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Monday, May 12
• Registration Foyer

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Plenary session 1 Mirror Hall

### Mirror Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Prof. Heino Nitsche (UC Berkeley and Lawrence Berkeley National Laboratory), Prof. Jan John (CTU in Prague, FNSPE, Department of Nuclear Chemistry)
• 2
Fukushima Accident: Radioactivity Impact on environment, land and ocean
Speaker: Prof. Michio Aoyama (Institute of Environmental Radioactivity, Fukushima University)
• 3
Progress and Status of Radioanalytical Chemistry of Radionuclides
Speaker: Prof. Xiaolin Hou (Technical University of Denmark, Center for Nuclear Technologies)
• 4
Positioning the New Elements in the Periodic Table
With the discovery of six new elements in the past decade an extraordinary expansion of the Periodic Table took place, so that now all elements of the 7th period have been synthesized. This success was possible by exploiting the concept of “warm” fusion using the available, neutron-rich actinide target materials and the tightly bound, doubly magic projectile 48-Ca [1]. Most of these discovery experiments were conducted by the Dubna-Livermore collaboration at the Flerov Laboratory in Dubna, Russia and a number of independent experiments have been able to confirm these findings [2-4], most recently for element 117 [5]. Due to the discovery of relatively long-lived isotopes of copernicium (element 112) and flerovium (element 114) first chemical experiments have successfully been conducted, revealing the special chemical properties of these elements, which can be attributed to the influence of strong relativistic effects [6,7]. Substantial progress has also been achieved in investigating the lighter heavy actinide and transactinide elements, where new properties of heavy actinide elements and new classes of tansactinide containing compounds have been synthesized. In my lecture I will review these recent developments and give an outlook on upcoming opportunities for chemical investigations of heavy and superheavy elements. [1] Yu.Ts Oganessian, J. Phys. G: Nucl. Part. Phys. 34, R165 (2007) [2] L. Stavsetra et al., PRL 103, 132502 (2009) [3] Ch.E. Düllmann et al., PRL 104, 252701 (2010) [4] S. Hofmann et al., EPJA 48, 1 (2012) [5] J. Khuyagbaatar et al., PRL in press (2014) [6] A. Türler, V.G. Pershina, Chem. Rev. 113, 1237 (2013) [7] A. Yakushev et al., Inorg. Chem. 53, 1624 (2014)
Speaker: Prof. Andreas Türler (Paul Scherrer Institute and Bern University)
• 10:00 AM
Coffe Break Marble Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Plenary session 2
Conveners: Prof. Andreas Türler (Paul Scherrer Institute and Bern University), Prof. Michio Aoyama (Institute of Environmental Radioactivity, Fukushima University)
• 5
Comparison of eight possible 99-molybdenum production routes
The present paper addresses eight possible routes of producing 99Mo, and discusses both yield and 99Mo specific activities (SA) in the context of future anticipated worldwide demand. The dimensions of the targets are modelled by considering both the limits set by cooling and those by inside-target radiation attenuation characteristics. Energy deposition profiles are modelled by MCNP6, the reaction probabilities are taken from TALYS/TENDL and JANIS codes, and both are used in calculating produced 99Mo. The results suggest that U neutron-fission may remain one of the most relevant and efficient means of producing 99Mo, but that new developments may surface, such as ADSR or AHR production modes. Accelerator- based 99Mo production is discussed as asking for developments in both the cooling of targets and new concepts in post-EOB upgrading of 99Mo SA, and/or new concepts for 99Mo/99mTc-generators, the latter possibly in both volumes (mass) and 99Mo capacities.
Speaker: Prof. Bert Wolterbeek (Delft University of Technology)
• 6
Chemistry for the Future Nuclear Fuel Cycles
Speaker: Dr Stéphane Bourg (CEA, Nuclear Energy Division, RadioChemistry & Processes Department)
• 7
Targeted Alpha Therapy Research - a Radiochemistry Perspective
Speaker: Dr Emma Aneheim (Sahlgrenska Academy at Gothenburg University)
• 12:15 PM
Lunch Marble Hall

### Marble Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Chemistry of Actinide and Trans-actinide Elements 1 Red Hall

### Red Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Prof. Andreas Türler (Paul Scherrer Institute and Bern University), Dr Ladislav Havela (Charles University)
• 8
Gas Phase Chemistry of Superheavy Elements
Gas Phase Chemistry of Superheavy Elements A. Yakushev1 1GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt, Germany a.yakushev@gsi.de Long-lived isotopes of superheavy elements (SHE) beyond Rf, i.e., with atomic number Z ≥ 104 can be produced via fusion reactions between heavy actinide targets and neutron-rich projectiles at a rate of only single atoms per minute (Z=104) or per week (Z=114). Investigating these neutron-rich SHE nuclei using rapid gas-chemical separation and subsequent on-line detection provides an independent chemical characterization and an alternative separation technique to electromagnetic recoil separators. Approaching the heaviest elements, the coupling of chemistry setups to a recoil separator promises extremely high sensitivity due to strong suppression of background from unwanted species. The use of a combination of two separation techniques, physical pre-separation and gas phase chemistry opens the possibility for investigating new compound classes of superheavy elements [1,2]. Electron shells of SHE are influenced by strong relativistic effects caused by the high value of Z. The lighter transactinides with Z = 104-108 were experimentally shown to be members of groups 4 through 8 of the Periodic Table of the elements [3]. Early atomic calculations predicted copernicium (Cn, element 112) and flerovium (Fl, element 114) to be noble gas-like due to the strong relativistic stabilization of the closed-shell configuration 6d107s2 in Cn, and the very large spin-orbit splitting in 7p AOs resulting in the quasi-closed-shell configuration 7s27p1/22 in Fl [4]. Recent fully relativistic calculations studying Cn and Fl in different environments suggest those to be less reactive compared to their lighter homologues in the group, but still exhibiting metallic character [5]. The dilemma whether Cn and Fl are noble gases or rather noble metals calls for experiments. Experimental gas-chromatography studies on Cn have, indeed, revealed a metal-metal bond formation with gold [6]. In contrast to this, for Fl, the unexpected formation of a weak physisorption bond upon adsorption on gold was inferred from first experiments [7]. The recent gas chromatography study on Fl upon the adsorption on gold was performed exploiting clean Fl samples, provided after the pre-separation with the gas-filled separator TASCA [8]. Two Fl decay chains were detected under background-free conditions. The observed behavior of Fl in the chromatography column is indicative of Fl being less reactive than the nearest homolog Pb. The evaluated lower limit of the adsorption enthalpy −ΔHads(Fl) > 48 kJ/mol (95% confidence level) reveals the formation of a metal-metal bond with Au, which is at least as strong as that of Cn, and thus demonstrates the metallic character of Fl [9]. In other experiments, a first molecule of a compound class, which was previously inaccessible for superheavy elements, was recently investigated. The adsorption behavior of Sg(CO)6 was studied by gas-solid chromatography in comparison with that of its nearest homologs in the group, Mo and W [10-12]. References /1/ Ch E. Düllmann et al., Nucl. Instr. Meth. A 2005, 551, 528–539. /2/ Ch.E. Düllmann et al., Radiochim. Acta 2009, 97, 403-418. /3/ A. Türler and V. Pershina, Chem. Rev. 2013, 113, 1237−1312. /4/ K.S. Pitzer. J. Chem. Phys. 63, 1032 (1975). /5/ V. Pershina et al. J. Chem. Phys. 131, 084713 (2009). /6/ R. Eichler et al. Angew. Chem, Int. Ed. 47, 3262-3266 (2008). /7/ R. Eichler et al. Radiochim. Acta 98, 133-139 (2010). /8/ A. Semchenkov et al. NIM B 266, 4153-4161 (2008). /9/ A. Yakushev et al. Submitted to Inorg. Chem., 2013. /10/ J. Even, et al., Inorg.Chem. 2012, 51, 6431-6422. /11/ J. Even, et al. Submitted to Radiochim. Acta, 2013. . /12/ J. Even et al., to be submitted to Science.
Speaker: Dr Alexander Yakushev (GSI Helmholtzzentrum für Schwerionenforschung GmbH)
• 9
Decomposition studies of W and Mo carbonyl complexes and their implications for future experiments with Sg(CO)6
Recent experiments at RIKEN (Japan) showed that Sg carbonyl (Sg(CO)6) can be produced with yields high enough for experimental investigation of its chemical properties [1]. According to theoretical calculations [2], which include so-called relativistic effects, Sg(CO)6 is expected to be slightly more stable than W(CO)6. In this work we aimed at designing an experimental setup for testing this theoretical prediction. Carbonyl complexes of W and Mo, as lighter homologues of Sg, were chosen for testing the setup. Gas-jet systems as well as the detection system used in our work are described in [1]. Two alpha-active tungsten isotopes were produced in fusion-evaporation reactions 144Sm(24Mg,xn)163-164W, while natZn(24Mg,xn)87-88W allowed for formation of β+-decaying molybdenum. The Gas-filled Recoil Ion Separator (GARIS) provided an effective separation of evaporation residues from the beam and from multinucleon transfer reaction products. Evaporation residues were thermalized in a recoil transfer chamber [3], flushed by a He/CO gas mixture. Formed carbonyl products [4] were transported to a decomposition column, held at different temperatures, and bypassed by a column of the same size made of PFA Teflon. Complexes transported through this bypass or the decomposition column were deposited at the low-temperature end of the COMPACT detector [1] according to their adsorption enthalpy and thus provided quantitative information about the production and the decomposition rates, respectively. Obtained results are discussed in the light of future experiments with Sg(CO)6. [1] J. Even et al., in preparation , and A. Yakushev, presentation at this conference. [2] C. S. Nash and B. E. Bursten, J. Am. Chem. Soc. 121, 10830-10831 (1999). [3] J. Even et al., Nucl. Instrum. Meth. A 638, 157-164 (2011). [4] J. Even et al., Inorg.Chem. 2012, 51, 6431-6422.
Speaker: Ilya Usoltsev (Paul Scherrer Institut)
• 10
Towards selenides of the superheavy elements copernicium and flerovium
Transactinide’s chemical behavior is similar to their lighter homologues in the corresponding group of the periodic table. However, with increasing nuclear charges, superheavy elements (SHE) show deviations from the periodicity of chemical properties [1]. An experimentally exceptionally favourable case for comparative studies is the possibility of a simultaneous production of Cn (Z=112) and Fl (Z=114) in Ca-48 induced nuclear fusion reactions with Pu-242 / Pu-244 [2]. Since these superheavy elements are characterized by short half-lives and low production rates, their chemical behavior has to be explored on a single atomic scale. For this purpose gas chromatography is used, allowing for efficient studies of the interaction of volatile gas-phase species with stationary surfaces [1]. Sulphur was chosen as stationary chromatography material for such a comparative studies. In fact, extrapolative predictions, in which thermochemical state functions are correlated mutually, showed that both Cn and Fl may form stable sulfides, and since the stability trends of sulfides formation in group 12 and 14 were predicted to be opposite, FlS was expected to be more stable than CnS. In preparation of the chemical investigations of these superheavy elements, isothermal model experiments with Hg (copernicium homologue) and sulfur surfaces were conducted. Although the formation of HgS(s) is thermodynamically favored (ΔHadsHg(S) < -75 kJ/mol), it was difficult to obtain reproducible results due to the slow interaction kinetics between the sulfur S8 rings (dominant sulfur allotrope at room temperature), and Hg. Recent studies reported amorphous nano-selenium as an efficient mercury sorbent, due to the high affinity of Se towards Hg and the high surface-to-mass ratios of the nanoparticles [3]. Hence, extrapolative predictions for the group 12 and 14 selenide formation were done. Again, stability trends in group 12 and 14 are predicted to be opposite: the formation of FlSe is expected to be favored or at least similar to the homologue selenides, while the interaction between Cn and selenium is expected to be a weak physisorption. The chemical system Hg / Se is an ideal model system to investigate the kinetics and thermodynamics of the adsorption and reaction of a volatile noble metal with selenium surfaces. Hence, first model experiments on the interaction of elemental Hg with red amorphous selenium surfaces, obtained through supercooling of high temperature Se vapors on quartz tubes, were performed. Here, first results from these investigations will be presented. Some conclusions will be drawn, which are important for the preparation of further chemical investigations of Cn and Fl. [1] M. Schädel in “The chemistry of Superheavy Elements” 2-d ed., Springer (2014). [2] Yu.Ts. Oganessian, J. Phys. G: Nucl. Part. Phys. 34, R165 (2007). [3] N. Ralston, Nature Nanotech. 9, 527 (2008).
Speaker: Mrs Nadine Mariel Chiera (Paul Scherrer Institute, University of Bern)
• 11
Production of 261Rf, 262Db, and 265Sg for chemical studies using GARIS at RIKEN
Recently, chemical characterization of superheavy elements (SHEs) with atomic numbers Z ≥ 104 is an extremely interesting and challenging research subject in modern nuclear and radiochemistry [1,2]. At RIKEN, we have been developing a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS as a novel technique for SHE chemistry [3–5]. This system is a promising approach for exploring new frontiers in SHE chemistry; (i) background radioactivities originating from unwanted by-products are strongly suppressed, (ii) an intense primary heavy-ion beam is absent in the gas-jet chamber and hence a high gas-jet yield is achieved, and (iii) the beam-free conditions also make it possible to investigate new chemical reactions. In this work, we investigated production and decay properties of long-lived radioisotopes of Rf (Z = 104), Db (Z = 105), and Sg (Z = 106) available for chemical studies [6–9]. Oxygen-18, 19F, and 22Ne beams were extracted from the RIKEN linear accelerator. The isotopes of 261Rfa,b, 262Db, and 265Sga,b were produced in the reactions of 248Cm(18O,5n)261Rfa,b, 248Cm(19F,5n)262Db, and 248Cm(22Ne,5n)265Sga,b, respectively. The evaporation residues of interest were separated in flight from the beam particles and the majority of the nuclear transfer products by GARIS and were guided to a gas-jet chamber at the focal plane of GARIS. The evaporation residues were then thermalized in He gas, attached to KCl aerosol particles, and were extracted through a Teflon capillary to the chemistry laboratory. Alpha and spontaneous fission (SF) decays of 261Rfa,b, 262Db, and 265Sga,b were measured with the rotating wheel apparatus MANON under low background conditions. In the conference, perspectives of the next-generation SHE chemistry opened by GARIS will be also presented. References [1] M. Schädel, Angew. Chem. Int. Ed. 45, 368 (2006). [2] A. Türler and V. Pershina, Chem. Rev. 113, 1237 (2013). [3] H. Haba et al., J. Nucl. Radiochem. Sci. 8, 55 (2007). [4] H. Haba et al., Eur. Phys. J. D 45, 81 (2007). [5] H. Haba et al., J. Nucl. Radiochem. Sci. 9, 27 (2008). [6] H. Haba et al., Chem. Lett. 38, 426 (2009). [7] H. Haba et al., Phys. Rev. C 83, 034602 (2011). [8] H. Haba et al., Phys. Rev. C 85, 024611 (2012). [9] H. Haba et al., Phys. Rev. C (in press).
Speaker: Dr Hiromitsu Haba (RIKEN)
• 12
Excitation functions for production of rutherfordium isotopes in the 248Cm + 18O reaction
Rutherfordium-261 (261aRf; T1/2 = 68s) has been used in chemical studies of element 104, Rf [1]. In recent years, it was reported that there exists a spontaneously-fissioning (SF) isomer (261bRf; T1/2 = 2.6 s) in 261Rf [2-6]. On the other hand, a SF isomer with the similar half-life of 2.1 s also had been reported as 262Rf (T1/2 = 47 ms) [7,8]. It is possible that these two SF isomers are the same and one of these is misassigned. In this work, the excitation functions of Rf isotopes in the 248Cm + 18O reaction were measured to clarify the ambiguity on the assignment of the fissioning isomers in 261,262Rf [9]. Rutherfordium isotopes were produced by bombarding the 248Cm target with an 18O beam supplied from the RIKEN linear accelerator. The beam energies were 88.2, 90.2, 94.8, and 101.3 MeV at the center of the target. A gas-filled recoil ion separator (GARIS) was used to separate the evaporation residues (ERs) in-flight from the incident particles and majority of by-products. ERs were then implanted into a position-sensitive Si strip detector mounted at the focal plane of GARIS. The beam on-off method was applied to measure the decay events of Rf isotopes under low background conditions. At each beam energy, beam on-off periods were set to 6 s-6 s and 0.1 s-0.1 s. The shape of the measured excitation function of 261aRf agreed with the previously reported one [10]. The excitation function of a-few-second SF nuclide exhibited the maximum cross section at 94.8MeV, and the shape of the excitation function was almost the same as that of 261aRf. On the other hand, short-lived SF decays were observed at 88.2 MeV and 101.3 MeV, and they were assigned to 262Rf and 260Rf, respectively. Such the short-lived SF decay was not observed at 94.8MeV. Therefore, we concluded that a-few-second SF nuclide previously assigned to both 261bRf and 262Rf is not 262Rf but 261bRf. References [1] M. Schädel, Angew. Chem. Int. Ed. 45, 368 (2006). [2] S. Hofmann et al., Eur. Phys. J. A 14, 147 (2002). [3] J. Dvorak et al., Phys. Rev. Lett. 97, 242501 (2006). [4] J. Dvorak et al., Phys. Rev. Lett. 100, 132503 (2008). [5] H. Haba et al., Phys. Rev. C 83, 034602 (2011). [6] H. Haba et al., Phys. Rev. C 85, 024611 (2012). [7] L. P. Somerville et al., Phys. Rev. C 31, 1801 (1985). [8] M. R. Lane et al., Phys. Rev. C 53, 2893 (1996). [9] M. Murakami et al., Phys. Rev. C 88, 024618 (2013). [10] Y. Nagame et al., J. Nucl. Radiochem. Sci. 3, 85 (2002).
Speaker: Mr Masashi Murakami (Nishina Center, RIKEN)
• Chemistry of Nuclear Fuel Cycle 1 Mirror Hall

### Mirror Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>

(1st ASGARD International Workshop)

Conveners: Prof. Christian Ekberg (Nuclear Chemistry, Chalmers), Mrs Václava Havlová (ÚJV Řež, a.s.)
• 13
Experiences of reprocessing plutonium rich mixed carbide fuels
The mixed carbide (70% Pu, 30% U) spent fuel from the Fast Breeder Test Reactor (FBTR) at Kalpakkam, India is being reprocessed at the CORAL facility since 2003. Several campaigns with progressively increasing burnups and reducing cooling periods have been carried out in this facility. Presently spent fuels with a burn up of 155 GWd/Te with cooling periods as around two years are being reprocessed. The satisfactory operation of this facility has provided valuable inputs for the design of process, equipment and other systems. Sustained operation of critical process equipment such as chopper, dissolver and solvent extraction equipment enabled in the fine tuning of design for reliable operation and easier maintenance. Design optimization for the future plants DFRP and FRP which are under construction for closing the fuel cycle of FBTR and Prototype Fast Breeder Reactor (PFBR) respectively could be carried based on the operating experience with single pin chopper. The apprehension that mixed carbide fuel would be difficult to dissolve and not give a satisfactory solvent extraction performance, is alleviated by the experience of quantitative dissolution and recovery of plutonium. Typical hull losses have been experimentally found to be less than 0.08% for plutonium. Though some carbide carbon was found to be there in the dissolver solution, it does not affect the solvent extraction performance. The highly oxidative dissolution conditions required for the dissolution of the spent fuel, call for material of construction other than the conventional stainless steel, as its corrosion rate of under such condition is unacceptably high. Alternate material of construction has been identified and deployed for the CORAL dissolver. Inspection of the dissolver after around three years of operation has revealed satisfactory performance. Though three solvent extraction cycles have been provided in the plant, it has been found that the required decontamination could be achieved with a single cycle. Typical decontamination factors of greater than 10**3 for Ru-106 and 10**4 for Cs-137 have been achieved. The recovery of plutonium and uranium are greater than 99.9% and 99.8% respectively. The centrifugal extractors have provided extremely satisfactory performance with progressive improvement in the performance in terms of reduced maintenance requirements with incorporation of design changes during the campaigns. R&D work has been concurrently taken up based on the performance evaluation of the facility for improving the recovery, decontamination factors, economy and reducing the waste volumes. With the computer code PUSEP(Ver-II) developed by the reprocessing group, IGCAR, an innovative extraction flowsheet is formulated to meet the decontamination requirements of both 95Zr and 106Ru while reprocessing fuels with less than two years cooling period. With this code it has been possible to establish the flow rate controls required for avoiding the third phase formation due to excessive plutonium loading in the solvent phase. Also, it has been found that closer to the stoichiometric requirement of uranous for separation of plutonium from uranium is possible. These findings will substantially reduce the number of solvent extraction cycles and hence the waste volumes. Reduction of solvent waste using vacuum distillation and the removal of dissolved organic by diluent wash using efficient contactors to address the red-oil formation during waste evaporation, are a few R&D activities in progress to improve the plant performance. Another important offshoot of the operation of the CORAL facility is the development of a variety of hot cell equipment and systems for remote operation and maintenance with least plutonium contamination in the operating area. Based on the satisfactory experience, it is expected that the reprocessing of PFBR spent MOX fuel would not pose a challenging problem as the plutonium content in PFBR is much less (around 25%).
Speaker: Dr Natarajan Rajamani (Indira Gandhi Centre for Atomic Energy)
• 14
Dissolution of carbide fuel materials
As part of the strategic research agenda for sustainable nuclear energy in Europe [1], carbide fuel is proposed as a potential candidate fuel for sodium cooled fast reactors and is the fuel of choice for gas cooled fast reactors. Carbide fuels have also been demonstrated to achieve high burn-up (> 155 GWd/t) in the sodium cooled Fast Reactor Fuel Reprocessing technology being pursued at the Indira Gandhi Center for Atomic Research (IGCAR), Kalpakkam. There are a number of issues that need to be addressed in the reprocessing of carbide fuel in order to demonstrate a sustainable closed nuclear fuel cycle. Carbide fuel can be problematic when applying the traditional PUREX reprocessing technology of solvent extraction from a nitric acid solution. The dissolution of uranium carbide (UC) in hot nitric acid can lead to the formation of soluble organic molecules that can interfere with the extraction of uranium and plutonium reducing their extraction and recovery efficiencies. The organics can also lead to emulsions causing difficulties within industrial processes. Even when the U and Pu have been removed from the soluble organics the remaining liquor contains highly radioactive fission products in the presence of organic material that requires volume reducing before immobilising in a glass matrix. The presence of organics can present a safety issue and needs to be effectively managed. In this paper we present the dissolution results from first titanium carbide (a potential barrier material in GCFRs) and then from unirradiated uranium carbide fast reactor blanket fuel pellets. The kinetics of dissolution will be discussed together with comments on the organic materials produced and carbon mass balance. [1] SNETP Strategic Research Agenda May 2009; Strategic Research and Innovation Agenda, Feb 2013.
Speaker: Mr Chris Maher (National Nuclear Laboratory)
• 15
Dissolution of Mo-based CERMET fuel: ESI-TOF MS Speciation in nitric acid medium
The main long term contributors to spent fuel radiotoxicity are plutonium followed by the minor actinides (MA = Np, Am, and Cm). A possibility to reduce the radiotoxic inventory and the footprint of the repository is to separate the most radiotoxic and long-lived elements from spent fuel and to transmute them into nonradioactive elements or elements with a much shorter lifetime. For the transmutation in accelerator-driven systems (ADS) fuels with a high content of Pu and MA are preferred. To increase the burn-up of transuranium elements (TRU) and to reduce the formation of new TRU inert matrix fuels (IMF) [1-3] are favored. These are ceramic substrates or metallic matrices with high thermal conductivity, which are free of uranium and also have small cross sections for reactions with neutrons. The reprocessability of (Pu,MA)-oxide within a metallic 92Mo matrix (CERMET) is under investigation within the EU project ASGARD [4]. Dissolution in nitric acid is the first step in reprocessing. Therefore, detailed knowledge of the speciation of molybdenum in nitric acid medium is crucial on the one hand to understand this dissolution process and on the other hand as a basis for the design of a tailored extraction process. The speciation of molybdenum has been studied intensively in hydrochloric and perchloric acid medium[5,6], but little is known about the speciation in nitric acid medium, especially at high acidities, which are relevant for the dissolution of IMF. The solution species of molybdenum in strongly acidic nitric acid medium need to be extensively characterized and quantified. Therefore, electrospray ionization mass spectrometry, which can probe the stoichiometry and relative abundances of solution species, was applied. Here, we present new experimental data on the speciation of molybdenum as a function of nitric acid concentration. Isotopically pure 98Mo powder was dissolved in nitric acid and measured with the ALBATROS ESI-TOF [7]. Monomeric, dimeric, trimeric, tetrameric, and pentameric cationic molybdenum species have been detected. Besides the presence of hexavalent Mo species the spectra show that pentavalent Mo species are present in solution in spite of the oxidizing condition in strong nitric acid. 1. Haas, D., et al., Energ Convers Manage, 2006. 47: p. 2724-2731. 2. Ouvrier, N. and H. Boussier, Procedia Chemistry, 2012. 7: p. 322-327. 3. Degueldre, C., J Alloy Comp, 2007. 444: p. 36-41. 4. http://asgardproject.eu/. 5. J. J. Cruywagen, J. B. B. Heyns, Polyhedron 2000, 19, 907-911. 6. P. Tkac and A. Paulenova, Separ Sci Technol, 2008, 43, 2641. 7. T.Bergmann et al., Rev. Sci. Instrum., 1989. 60: p. 347.
Speaker: Ms Elena Laura Ebert (Forschungszentrum Jülich GmbH IEK-6)
• 16
Radionuclide distribution in corrosion layers of historic radioactive waste of NPP A1
Speaker: Mr Boris Andris (VUJE a.s.)
• 17
Study on sorption and diffusion of Sr in crushed and intact basalt and granite investigated in column method
This study investigates sorption and diffusion of Strontium (Sr) in two potential host rocks (granite from Kinmen Island and basalt from Penghu Island) by using batch and through-diffusion methods in order to establish a reliable safety assessment methodology. These methods were applied to crushed and intact rock samples to investigate the actual geological environment. According to solid-phase analysis, including X-ray diffraction, elemental analysis, auto radiography, and polar microscopy, the sorption component primarily contained iron–magnesium (Fe–Mg) minerals in basalt and granite. Moreover, the distribution coefficient (Kd) of Sr in various concentrations (~10−2–10−7 M) obtained from batch tests indicated a higher sorption capacity in basalt than that in granite because of the 10% Fe–Mg mineral content. The diffusion of Sr both in granite and basalt reach steady state after 100 days and apparent diffusion coefficient (Da) were 3.29×10-11 m2/s (for Sr in crushed granite), 4.17×10-12 m2/s (for Sr in crushed basalt), respectively. However, diffusive result (Da) of Sr in intact rocks was estimated a lower value than those obtained using crushed rocks. According to the diffusive results in crushed and intact rocks, it showed that major retardation of Sr depended on the microporous structure of tested media, such as decreases of constrictivity (δ) and increases of tortuosity(τ). In fact, the solid/liquid (S/L) ratio decreased as is the case when switching from batch to column experiments and the sorption effect on minerals became even more negligible in retardation of radionuclide migration.
Speaker: Prof. Ming-Chee Wu (Department of Earth Sciences, National Cheng Kung University, Tainan, Taiwan)
• 3:00 PM
Coffe Break Marble Hall

### Marble Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Nuclear Analytical Methods 1 Mirror Hall

### Mirror Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Dr Jan Kučera (Nuclear Physics Institute), Prof. Xiaolin Hou (Technical University of Denmark, Center for Nuclear Technologies)
• 18
Biochemical neutron activation analysis (BNAA) in pre- and post-genomic era of proteomics and metabolomics
Neutron activation analysis (NAA) is a well-established analytical technique for the simultaneous measurement of multielement concentrations. The most common forms of NAA are instrumental (INAA), radiochemical (RNAA) and preconcentration (PNAA). We have previously reported the development of speciation NAA (SNAA). We are also interested in the development of biochemical NAA (BNAA) methods for the separation, purification, characterization, and measurement of metalloproteins and organic compounds containing trace elements which are of biological/biochemical importance. We take advantage of the unique features of both techniques. For example, we need an analytical technique capable of analyzing a few milligrams of solid as well as liquid samples non-destructively and independent of chemical species, and of determining trace levels of several elements simultaneously within a short time in a matrix largely composed of carbon, hydrogen, nitrogen, oxygen and sulfur. Of course, the technique should provide excellent precision, accuracy, sensitivity, and detection limits. NAA meets all of these requirements. The biochemical techniques of interest are dialysis, ammonium sulphate precipitation, gel filtration, ion exchange and hydroxyapatite chromatography, high-performance liquid chromatography, chromatofocusing, isoelectrofocusing, isotachophoresis, sedimentation equilibrium and enzymatic assay. We called this combination of two techniques BNAA which is ideally suited for studying metalloproteins, protein-bound trace elements, and organometallic compounds. We observed that most of the trace elements in bovine kidneys, for example, were largely concentrated in the cytosol fraction. More than 70% of As, Br, Cl, Co, K, Na and Rb, about 65% of Cd, and 30-35% of other elements except Se (14.4%), Cr (15.6%) and Mo (24.6%) were detected in this fraction. Elements such as Ca, Cr, and Se were more abundant in the nuclei fraction with concentrations of 34%, 75% and 73%, respectively. The dialysis experiments showed that more than 90% of Ca, Cd, Cu, Fe, Mg, Mn, Mo, Se, V and Zn, and possibly As, and I, and about 20% of Br were bound to macromolecules, mainly proteins. Most of these proteins were stable in the pH range of 3.5 to 10.5. We separated and purified several metalloprotein species. Examples of these species with particular emphasis on Se will be presented.
Speaker: Prof. Amares Chatt (Dalhousie University)
• 20
Measurement of selenium levels in cultivated Japanese and Korean oysters and Japanese rock oysters using the 17.4-s neutron activation product 77mSe
Oysters in Japan are mainly cultivated in Miyagi, Hiroshima, and Hokkaido Prefectures. Sometimes baby cultivated oysters are exchanged between Japan and Korea; so both cultivated oysters are said to be genetically similar. Since Japanese consume a fair amount of raw oysters, it is of interest to compare the elemental levels of oysters from different areas. Soft tissues of cultivated Japanese oysters (Miyagi Prefecture, 2004 Nov, at 1, 6 and 11 m depths), Korean oysters (Koje-do and Kosong in Busan, 2002 Oct, 2004 Jan, and 2005 Dec), and Japanese rock oysters (Honshu Island) were analyzed for selenium levels. The soft tissues, namely hepatopancreas, gill, muscle, and mantle were separated, freeze-dried, pulverized, and analyzed by an instrumental neutron activation analysis (INAA) method in conjunction with Compton suppression spectrometry (INAA-CSS). The method consisted of irradiation of samples for 12 s in a neutron flux of 5x1011 cm-2s-1 using the rapid cyclic pneumatic sample transfer system at the Dalhousie University SLOWPOKE-2 reactor (DUSR) facility, decay for 15-20 s, and counting for 60 s. The 161.9-keV gamma-ray of the 17.4-s nuclide 77mSe was used for assaying selenium. The method was validated using NIST, NRC and NIES certified reference materials. An absolute detection limit of 0.15 µg selenium using NIST SRM 1566b Oyster Tissue was achieved. Selenium levels between Japanese and Korean oysters did not show much difference. The selenium concentrations in Japanese rock oysters showed the following trend: gill > hepatopancreas > mantle > muscle.
Speaker: Dr Michiko Fukushima (Ishinomaki Senshu University)
• 21
Comparison of INAA and LC-ICP-MS for the determination of As species in marine tissues
The aim of this work was to acquire traceable quantitative results for total As in whole samples as well as in extracts containing As species. Instrumental neutron activation analysis (INAA) is well suited for such measurements and is used in this work to validate the As mass fraction determined by liquid chromatography combined with inductively coupled plasma mass spectrometry (LC-ICP-MS) in tuna fish and kelp candidate RMs and other marine samples, including certified RMs. INAA was used to determine total As and trace elements in original solids, extracted solids, and in extracts as well as LC fractions; LC-ICP-MS was limited to the determination of As species in extracts. Extraction yields were determined by INAA for a number of common solvents and extraction techniques; the best results were acquired after methanol/acetone/water extraction with sonication. This procedure was used for quantitative As species evaluation with LC-ICP-MS incorporating internal standards and single point standard addition, while the sum of all As fractions was monitored by INAA. In the case of tuna tissue, AB was the predominant species determined by LC-ICP-MS and its As mass fraction was 4.41 ± 0.09 mg/kg. The total extracted As by INAA was 4.88 ± 0.27 mg/kg. In case of the BCR 627 certified RM the sum of AB + DMA was 4.15 ± 0.10 mg/kg, measured as AB = 3.99 ± 0.08 mg/kg and DMA = 0.148 ± 0.010 mg/kg in good agreement with the certified values, and the total As extracted was 4.28 ± 0.18 mg/kg by INAA summing up with As in the residue to 4.75 ± 0.17 mg/kg in excel-lent agreement with 4.81 ± 0.11 mg/kg determined by INAA in the original material. These differences between the techniques may be explained by relatively too high dissolution required by LC-ICP-MS not detecting very low mass fractions of other species in the extracts, and/or retention of As on the column. To completely evaluate the LC-ICP-MS process INAA detection limits were lowered utilizing the Compton suppression technique in the gamma spectrometry to reach below 0.2 ng sensitivity, which is sufficient to determine As in LC effluent fractions. LC effluent fractions were collected according to the time intervals recorded by the ICP-MS, reduced in volume, and transferred and dried on Whatman 542 filter substrate. These were subsequently submitted to INAA. The initial results showed As in the background (blank) fractions of the chromatogram, however most of it due to solvent blank. Arsenic in these fractions is not captured by ICP-MS and thus would explain the difference. Further, the quantitative determination of As by INAA in the chromatogram peaks provided a direct measurement of each separated species and allowed for calibrated determination of each species. Species, including those not available as standards, e.g., the arsenosugars found in kelp, can be accurately determined by INAA and used as calibrants. INAA and LC-ICP-MS thus were successfully used as complementary techniques for characterization and traceability studies related to the development of RMs for As species.
Speaker: Dr Rolf Zeisler (National Institute of Standards and Technology)
• Separation Methods, Speciation 1 Red Hall

### Red Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>

(session dedicated to the memory of prof. Věra Jedináková-Křížová)

Conveners: Andreas Geist (Karlsruhe Institute of Technology (KIT)), Dr Mojmír Němec (CTU FNSPE, Department of Nuclear Chemistry)
• 22
Complexation and Extraction of An(III) and Ln(III) with water-soluble SO3-Ph-BTBP
The recycling of minor actinides as nuclear fuel is complicated by the presence of curium due to its short term thermal power and neutron dose rate. Thus the development of processes for separating americium from curium are of particular interest. A new system was developed to separate only americium, addressing some of the challenges with the EXAm process such as a narrow pH window. The so called AmSel process uses water soluble SO3-Ph-BTBP and TODGA’s for Am(III), Cm(III), and Ln(III) separation. Am(III) + Cm(III) + Ln(III) distribution ratios as a function of HNO3 and SO3-Ph-BTBP concentrations were determined in extraction experiments. At low nitric acid concentrations the separation factor of Am(III) over Eu(III) exceeded 1000 and decreased with increasing acid concentration. The formation of 1:2 An(III)- and Ln(III)-aq-BTBP complexes was proven by time-resolved laser fluorescence spectroscopy (TRLFS) investigations of the aqueous phase after extraction. Furthermore, separation factors of Am(III) and Cm(III) for the aq-BTBP/TODGA system were determined at various experimental condition, varying between 1.5 and 3.2. The extraction studies revealed that stripping Am(III) from a loaded TODGA solvent is not impeded by slow kinetics. Buffers or salting out agents are not required. For a better understanding of the selectivity of SO3-Ph-BTBP towards An(III) over Ln(III) the complexation of Cm(III) and Eu(III) with SO3-Ph-BTBP was studied by time-resolved laser fluorescence spectroscopy (TRLFS). Conditional complex formation constants of the 1:2 An(III) and Ln(III) complexes were determined at pH 3 and in 0.5 mol/L HNO3. Though the stability constants of the 1:2 An(III) and Ln(III) complexes at 0.5 mol/L HNO3 were lower than at pH 3 by several orders of magnitude, the difference in the stability constants of two orders of magnitude between Cm(III) and Eu(III) remained constant. These results are in excellent agreement with the selectivity determined in the extraction studies and proves that the selectivity of SO3-Ph-BTBP towards An(III) over Ln(III) is preserved even at highly acidic conditions. Furthermore, to explain the significant decrease of the stability constants of the 1:2 An(III) and Ln(III)-SO3-Ph-BTBP complexes at 0.5 M HNO3, fundamental studies on the impact of different parameters such as ionic strength, nitrate complexation and protonation of the ligand were performed. These studies revealed valuable mechanistic information on complexation reactions including the impact of competing reactions and/or ionic strength effects at various experimental conditions.
Speaker: Prof. Petra Panak (University of Heidelberg)
• 23
Separation of Minor Actinoids(III) over Lanthanoids(III) by BTBP or BTPhen Extracting Compounds
Different extraction systems for the separation of trivalent minor actinoids over lanthanoids were studied during last years. The CyMe4-BTBP and its derivatives have been demonstrated to be prospective extractants for the solvent extraction of minor actinoids over lanthanoids from high-level liquid waste issuing the reprocessing of irradiated nuclear fuel (the r-SANEX process). The presentation will be focused on different effects of 1,2,4-triazine extracting compounds and diluents on extraction systems properties. The results of testing the CyMe4-BTBP ligand and its new derivatives (such as Cy5-S-Me4-BBP, Cy5-O-Me4-BTBP, MeCyMe4-BTBP or t-BuCyMe4-BTBP) for the separation of Americium(III) over Europium(III) from HNO3 solutions and influence of the used diluents (both polar and non-polar) will be discussed. Moreover, complexing properties of several novel hydrophilic ligands, such as (PhSO3Na)2-BTBP, (CH2NMe3)2-BTBP or (PhSO3Na)2-BTPhen will be described as prospective agents for i-SANEX process. In addition to the dependences of Americium(III) and Europium(III) distribution ratio values and their mutual separation factor values on HNO3 concentrations, the results of the thermodynamic and kinetic studies will be presented.
Speaker: Mr Petr Distler (CTU in Prague)
• 24
Actinide stripping by a hydrophilic BTP ligand in aqueous HNO3 from TODGA-containing organic phase
N,N,N′,N′-tetraoctyl-diglycolamide (TODGA) is broadly studied as a non-specific extractant for actinides and lanthanides from HNO3 solutions of nuclear waste, in particular for group actinide extraction (GANEX process). Geist and his coworkers proposed a novel hydrophilic ligand, 2,6-bis(5,6-di-(sulfophenyl)-1,2,4-triazin-3-yl)pyridine (SO3-Ph-BTP) for selective stripping of actinides(III) from the loaded organic phase [A. Geist et al., Solvent Extr. Ion Exch., 30, 433 (2012)], and determined (by TRLFS) the stability constants of its consecutive (from 1:1 to 1:3) complexes with Cm(III) and Eu(III) in aqueous solutions [C.M. Ruff et al., Dalton Trans., 41, 14594 (2012)]. In the present work, we studied the distribution of some actinides(III-VI) in the two-phase systems: TODGA (in kerosene) / SO3-Ph-BTP (0–100 mM in aqueous HNO3); and determined the apparent stability constants of their complexes in the aqueous phase, based on the distribution ratios of the metal ions. The effect of protonation of the SO3-Ph-BTP ligand in the acidic solutions was discussed. This work was financed from the National Centre for Research and Development through the Strategic Program Technologies Supporting Development of Safe Nuclear Power Engineering, task 4: Development of spent nuclear fuel and radioactive waste management techniques and technologies.
Speaker: Mr Łukasz Steczek (Institute of Nuclear Chemistry and Technology)
• 25
Various Flowsheets of Actinides Recovery with Diamides of Heterocyclic Carboxylic Acids
Various neutral ligands are studied as potential ligands for separation of actinides from lanthanides. The most effective extractants for selective recovery of actinides from high level wastes are poly nitrogen compounds. The presence of several “soft” donor atoms in ligand structure allows to reach very high Am/Eu separation factor values. Recently a new class of neutral polydentate compounds – diamides of heterocyclic dicarboxylic acids – was proposed for recovery of f-elements from nitric acid. Ligands belonged to this class possess in their structure both “hard” oxygen and “soft” nitrogen atoms. Such combination of coordination centers provides high extraction ability of ligand toward f-elements and better affinity to actinides than lanthanides. Diamides of 2,6-pyridine-dicarboxylic acid, diamides 2,2'-dipyridil-6,6'-dicarboxylic acid, diamides of 6,6’’-(2,2’:6’,2’’-terpyridine)dicarboxylic acid, amides of 1,10-phenanthroline-2-carboxylic acid and diamides of 1,10-phenanthroline-2,9-dicarboxylic acid were synthesized and tested for extraction of actinides (III, IV, V, VI) and lanthanides (III) from nitric acid solutions. In our work we studied extraction properties of diamides of 2,6-pyridine-dicarboxylic acid (DPA) and diamides 2,2'-dipyridil-6,6'-dicarboxylic acid (Dyp). DPA effectively extract actinides (III, IV, VI) and lanthanides (III) from nitric acid solutions. Actinides are extracted better than lanthanides. The Am/Eu separation factor up to 6 for extraction from 1-2 M HNO3 can be reached. Solutions of DPA in polar fluorinated diluents have very high loading capacity on extracted metals and can be used for recovery of actinides from wasted with high lanthanides content (more than 17 g/L) Dyp have in their structure two pyridine rings and are more selective extractants than DPA. Americium can be selectively extracted from lanthanides with separation factors more than 10. In the present work two flowsheets for actinides recovery and separation them from lanthanides on the base of DPA and Dyp were developed. Both schemes were tested in laboratory scale using simulate solutions of raffinates with high content of fission products.
Speaker: Dr Mikhail Alyapyshev (Khlopin Radium Institute)
• Poster Session - Nuclear Analytical Methods
• 26
90Y Cherenkov radiation measurement for 90Sr determination
Isotope of strontium 90Sr (one of the nuclear fission products with half-life 28.9 years) is well known for its biochemical similarity with calcium and possible consequent incorporation into human body. Main risk presents its daughter product 90Y (half-life 64.1 hours), which is a high energy β-emitter (Eβ,max=2.28 MeV). That is why the development of fast and effective method of 90Sr determination or monitoring is ongoing last 50 years and it is still one of the important topics. Hence, current demands call for advanced and less time-consuming methods for 90Sr determination. Main aim of this research was focused on the 90Sr determination in simulant solutions of environmental samples without the necessity to wait for the equilibrium with 90Y. This approach is crucial for the development of rapid method of 90Sr determination in environmental samples. Activity of 90Sr was measured through its daughter product 90Y using Cherenkov counting on HIDEX 300 SL and TRIATHLER (both Hidex Oy, Finland) liquid scintillation counters. Two type of samples were used for measurement. The Cherenkov radiation was measured from samples containing equilibrium amount of 90Y or from samples where 90Y growth is observed. A set of solutions with different diffraction indexes and set with different wavelength shifters for increasing Cherenkov radiation yield/detection was studied. It was find out that composition of the solution strongly affects measured background and hence further optimization of the sample content and parameters measurement is necessary. The activity obtained via Cherenkov counting were compared and verified using liquid scintillation counting of 90Sr, similar comparison was done between Triathler (1-photomultiplier) and HIDEX 300 SL (3-photomultipliers, TDCR) measurements.
Speaker: Mr Soběslav Neufuss (CTU in Prague)
• 27
A Comparison of expanded uncertainties for measuring iodine levels in nutritional materials by pseudo-cyclic epithermal INAA-AC using single comparator and k0 methods
A combination of different types of instrumental neutron activation analysis (INAA) technique was developed for the determination of iodine in various food items from Ghana [1]. The methods involved conventional INAA, epithermal INAA (EINAA), pseudo-cyclic INAA (PC-INAA) and pseudo-cyclic EINAA (PC-EINAA) in conjunction with conventional and anti-coincidence (AC) gamma-ray spectrometry using both single comparator and k0 standardization methods. The uncertainties associated with these methods were evaluated following ISO GUM procedures. The trueness of the methods were checked by analyzing several reference materials (RM) and standard reference materials (SRM) provided by the U.S. National Institute of Standards and Technology (NIST). Our results were in good agreement with the certified values. The expanded uncertainties associated with the measurement of iodine levels in NIST RM 8415 Whole Egg Powder by a PC-EINAA-AC method using the single comparator and k0 standardization procedures will be presented. The expanded uncertainty (κ = 2, ~95% CL) of 1.81 ±0.48 was obtained for the k0 procedure compared to that of 1.85 ±0.22 for the single comparator procedure. The value for the k0 procedure appears to be slightly influenced by the uncertainties in the nuclear constants and detector full photopeak efficiency determination. Reference 1. B.J.B. Nyarko, Ph.D Thesis, University of Cape Coast, Cape Coast, Ghana (2007)
Speaker: Prof. Amares Chatt (Dalhousie University)
• 28
A new formulation of effective states of “atoms in compounds”. application to study hyperfine structures and chemical shifts of x-ray emission lines.
Concepts of oxidation number state of an atom in a molecule and related theories are extremely useful in chemistry. At the same time, a good (clear and unambiguous) definition of the state of an atom in a molecule does not exist. Various methods of determining it from calculations lead to different results [1]. Each of known definitions has its drawbacks. The methods based on the use of one-electron density matrices (Mulliken or Löwdin populations analyses, etc.) are basis set dependent. The methods that use the electron densities (Bader or Hirschfield charges, Voronoi cells), suggest introduction of some complementary (artificial) notions or partitioning a molecule (solid) on regions in a manner that is not arising from any of physical principles. There is a number of experimentally observed properties of compounds, depending on a distribution of the valence electron densities or their changes in the atomic core regions. They include chemical shifts of X-ray emission spectra [2], hyperfine structure constants, isotope (volume) shifts, etc. Earlier our group has developed a two-step method to calculate these properties through first-principle based electronic structure calculations within the generalized relativistic pseudopotential approximation followed by a posteriori restoration of the information on the wave functions in the atomic core regions that is missed in the results of pseudopotential calculations [3]. On the basis of this two-step method one can formulate an approach for determining the state of an atom in a molecule (compound). A radius Rc of the core region is determined by the smallness of interaction of valence electrons located within a sphere (r < Rc) with the external (chemical) environment (r > Rc) compared to their interaction with the nucleus and core electrons of a considered atom. Using the properties of proportionality of valence spinors in the atomic core region with the radius Rc [4], one introduce some new terms: "charges of partial waves" for valence electrons in the core region, "reduced population numbers" and one-center density matrices "reduced on the radial quantum number nr". It is shown that the above-discussed properties characterized by the state of an atom in a compound rather than by chemical bonds are well described by only these terms. Results of calculations of the properties of atoms and molecules are presented. The work is supported by the SPbU Fundamental Science Research grant from Federal budget #0.38.652.2013 and RFBR grant #13-03-01307-a. 1. C.J.Cramer, Essentials of Computational Chemistry: Theories and Methods, (2002,Wiley). 2. Y. V. Lomachuk and A. V. Titov, Phys. Rev. A 88, 062511 (2013). 3. Titov A.V. et al., Int. J. Quant. Chem., 104(2), 223 (2005). 4. Titov A.V., Mosyagin N.S., Int. J. Quant. Chem., 71(5), 359 (1999).
Speaker: Yuriy Lomachuk (Petersburg Nuclear Physics Institute, Gatchina, Russia; Dept. of Physics, St. Petersburg State University, Petrodvoretz, Russia)
• 29
A simple determination of 41Ca by ICPMS in concrete samples as a tool for the decommissioning of nuclear facilities
Speaker: Dr MAURO CAPONE (ENEA)
• 30
Accelerator mass spectrometry of uranium: comparison of U<sub>3</sub>O<sub>8</sub> and UF<sub>4</sub> target matrices
For determination of 236U/238U ratios in environmental samples by accelerator mass spectrometry, the U3O8 targets are usually used for the UO- beam production. Uranium fluoride targets containing no oxygen and hydrogen may offer higher molecular isobar suppression together with a higher accuracy and sensitivity of uranium isotope analysis1. However, the preparation of anhydrous UF4 targets is more complicated than the preparation of U3O8 targets. When introducing inert atmosphere into the dehydration step of the preparation the only partial reduction of oxygen and hydrogen content in the final product of the preparation method was assured. In this work, several U3O8 and UF4 targets were tested in the CENTA laboratory using the MC-SNICS ion source and double focusing injection magnet and the targets were prepared using the Vienna KKU standard with 236U/238U isotopic ratio of 10-11. The detailed study of anhydrous UF4 preparation method will be performed in CTU laboratories. The ion current from only one UF2- sample was in average higher by about 50 % than the UO- current from the U3O8 samples. The targets were completely sputtered away, and the estimated ionization yields of UO- and UF2- were of the order of 10-3. However, with the improved procedure of the UF4 targets production, we expect that even higher ionization yields could be obtained. REFERENCES 1. Wang X.: Nucl. Technol., 2013(182), 235.
Speaker: Irena Špendlíková (Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, 115 19 Prague, Czech Republic)
• 31
Americium winning for its determination in boric-acid containing NPP evaporator concentrate
The aim of this research was to develop a method for pre-concentration of americium from operational radioactive waste for its determination. In these experiments, the attention was paid to separation of americium from boric acid containing evaporator concentrate coming from the Dukovany Nuclear Power Plant by an extraction chromatographic system, where extraction agent used was N,N,N’,N’-Tetraoctyl Diglycolamide (TODGA) incorporated in polyacrylonitrile (PAN) matrix. For the elution of retained americium, the oxalic acid solution was chosen. Eluted americium has been, subsequently, determined by alpha spectrometry. Alpha samples were prepared using constant current electrodeposition technique from oxalate-sulfate electrolyte. The system characterization consisted of several experiments. At first, the dependence of americium weight distribution ratios on pH (ranging between 1.5 and 5.5; adjusted with nitric acid solutions) for four different dilutions of evaporator concentrate was studied, as well as blank experiments where americium weight distribution ratios dependences on pH for every dilution curve were determined for sorption on polyacrylonitrile matrix itself. Next, kinetics of this process, capacity of the used solid phase extractant, and elution profile of americium stripped by oxalic acid and loaded from various solutions were determined. Also the extraction behavior of americium in presence of various anions (namely nitrates, sulfates, oxalates, citrates and chlorides) in scale which can occur in real samples was investigated. The parameters of the electrodeposition process were optimized in an independent series of experiments; the most effective parameters were applied for the alpha samples preparation. Effectiveness of the electrodeposition method was monitored by comparing with simultaneously used liquid scintillation counting (LSC) method. As a result of a kinetics study, it was found out that about 97 % of americium uptake has been reached after half an hour of phase contact. The study of americium elution from TODGA-PAN resin filled column of bed volume equal to 0.24 mL, after its loading from the boric acid containing evaporator concentrate, revealed that almost all of the approximately 6 kBq of Am-241 loaded (97.43 ± 0.97 % or 98.26 ± 1.77 %, depending on the detection method used) could be eluted by about 1.7 mL of 0.25M oxalic acid solution.
Speaker: Mr Pavel Bartl (CTU in Prague)
• 32
An elemental portrait of the Portuguese wheat collection (in 2013) by instrumental neutron activation analysis
More than just being one of the "big three" cereal crops (with maize and rice), wheat is the staple food of humankind, with a history that is closely intertwined with humanity's own. Even if up to 100,000 plant species have been used -- on a regular or occasional basis -- since prehistoric times to meet the various needs (food, clothing, shelter, health) of an ever growing human population, wheat and its wild ancestors most likely were at the locus of an amazing evolutionary step that turned hunting and foraging/gathering individuals into settlers and, eventually, farmers. Domestication of diploid wild einkorn and tetraploid wild emmer is arguably thought to have begun some 10,000 years ago, although incipient cultivation of autochthonous landraces may have started well before that, in the early Holocene. The origins of such an agricultural beginning can be traced back to the vast and geographically diverse expanses of the Fertile Crescent in southwest Asia and the Middle East, while agriculture itself is, of course, the prominent feature of the so-called Neolithic Revolution, especially in what concerns cereal domestication (the above-mentioned einkorn and emmer wheats, and also wild barley). The status of wheat as the universal cereal of ancient agriculture has been kept through this day. Tonnage (though not acreage) of wheat grown worldwide may have been overtaken by both maize's and rice's shortly before the turn of last century, yet wheat remains unrivalled as to its latitudinal range of cultivation, crop area proper, caloric and nutritional relevance, and, last but not least, cultural significance at large. Current production is unevenly split between an overwhelming majority of hexaploid bread wheat (about 95 %), and a remaining share of (mostly) tetraploid durum wheat plus small amounts of hulled-grain wheat species (einkorn, emmer, spelt). Given such a background, no wonder that wheat germplasm was among the first to be stored in archival collections and seed banks, despite early general (technical) difficulties in preserving genetic resources as germplasm holdings. Besides, it is only fitting that wheat was the founding subject of one of the longest-running experiments in the history of science, the Broadbalk experiment at Rothamsted, UK (1843-present) -- 170 years and counting! Following the first morphological and taxonomic inventory of Portuguese wheats (1933), a collection of wheat cultivars has been maintained, replanted and documented by the National Institute of Agricultural and Veterinary Research, specifically by its former division known as the National Station for Plant Improvement (ENMP, Elvas). The ENMP collection has always been an invaluable asset in studies of agronomic and/or genetic development of wheat lines, as well as providing a reference frame for the nutritional evolution of Portuguese wheat crops. This work addresses the current status of major elemental nutrients and contaminants in a pool of 97 accessions of bread (52) and durum (45) wheat. All grain samples were irradiated at the Portuguese Research Reactor (RPI; CTN-IST, Sacavém) for 5 h, at a thermal-neutron flux density of 2.25E12 neutron per square cm and s, together with comparator disks of Al-0.1%Au. Gamma spectra were acquired with a liquid nitrogen-cooled, high-purity Ge detector. Elemental concentrations were determined through k0-standardized, instrumental neutron activation analysis (k0-INAA), and quality control was carried out by concurrent analysis of NIST-SRM 1567a, NIST-SRM 1568a and INCT-OBTL-5. In the discussion, focus will be given to essential nutrients like Fe, Mg, Se and Zn, and also to historical trace contaminants like As, as compared to current ionomic traits in modern European wheats. Special attention is paid to the (low) levels of Se, for which wheat acts as an important source in human diets, with a view to curbing its deficiency in Portuguese cultivars through agronomic biofortification.
Speaker: Ms Catarina Galinha (CERENA-IST, University of Lisbon)
• 33
Analysis of Hg and Pb by ICP-MS for the study of phytoremediation of Pb and Hg by Scirpus mucronatus
Phytoremediation is a procedure that uses plants to remove contaminants from the environment and it is a better option of recovery technique because of its cost-effectiveness and environmentally friendly especially for hyperaccumulator plants. Since heavy metals such as lead (Pb) and mercury (Hg) have limited bioavailability in the soil, methods to facilitate their transport to the shoots and roots of plant are required for efficient phytoremediation. The objective of this study was to investigate the effects of adding different heavy metal-tolerant bacterial inoculums (Brevundimonas diminuta SF-S1-5 and Alcaligenes faecalis SF-S1-60) on Pb and Hg accumulation in the shoots and roots of Scirpus mucronatus. The experiment was done in a greenhouse by planting acclimatized S. mucronatus in crates (52 cm length x 30 cm width x 25 cm height) with 30 kg sand and spiked with 100 ppm Pb and 1 ppm Hg, separately. The bacterial inoculums were added into the soil and the plants were watered using tap water to ensure the growth. The plants and sand samples were collected on day 1, 7, 14, 28 and 42, and the heavy metals in plant samples were extracted by using wet digestion method. The total concentration of Pb and Hg in samples was analyzed using Inductively Coupled Plasma-Mass Spectrometry(ICP-MS) and Atomic Absorption Spectrometer (AAS), respectively, and the phytoextraction ability was assessed in terms of its metal transfer factors; bioaccumulation factor (BAC), bioconcentration factor (BCF) and translocation factor (TF). Experimental results showed that after 42 days of treatment, the highest accumulation of Pb in shoot (265.8 ± 47.3 mg/kg-1 dryweight) was found in control plant (no addition of bacteria), while in root (697.2 ± 8.5 mg/kg-1dryweight) was found in plant inoculated with A. faecalis SF-S1-60. On the other hand, the highest accumulation of Hg (2.21 ± 0.08 and 5.71 ± 0.31 mg/kg-1 dryweight in plant shoot and root, respectively) were obtained in plant inoculated with A. faecalis SF-S1-60. In addition, plant inoculated with A. faecalis SF-60 showed the highest BAC and BCF values, and the lowest TF value compared to plant inoculated with B. diminuta SF-S1-5 and the control plant. This suggests that A. faecalis SF-60 can be utilized as an enhancer for accumulation of Pb and Hg in soil by S. mucronatus.
Speaker: Prof. Ainon Hamzah (Universiti Kebangsaan Malaysia)
• 34
Analysis of Lithium and Boron of Production and Real Samples using Cold Neutron Depth Profiling Method
Neutron Depth Profiling (NDP) is a nondestructive near surface method that can analyze the component nuclide concentration versus depth distribution in a sample by detecting the charged particles emitted after the neutrons are absorbed. NDP technique has became an important method to measure depth profiles of light elements such as lithium and boron in lithium battery and semiconductor materials. The Korea Atomic Energy Research Institute NDP (KAERI-NDP) facility has been installed at the HANARO research reactor. For the first application of the KAERI-NDP system, boron implanted and lithium deposition samples were prepared for depth profiling of 6Li and 10B. Additionally, electrode film samples were prepared by disassembling the lithium ion battery used in the mobile phone. The production and real samples were installed at the target chamber of the KAERI-NDP system and irradiated for different times with cold neutrons at the CG1 guide of the HANARO. The charged particle spectra were measured by using ion implanted Si detector. Measured spectra were analyzed and depth profiles of 6Li and 10B were determined. For the production samples where 10B implanted into the Si wafer, peak depth, peak concentration and aerial density was matched with those of SIMS method within 2, 6, 9%, respectively. In the case of lithium deposition samples, there was a difference of 6Li concentration profile in the deep region for the thick sample. 6Li concentration of the cathode of lithium battery was 5 times higher than that of the anode sample.
Speaker: Dr Byung Gun PARK (KAERI)
• 35
Application of ICP-MS for the determination of 99Tc and 90Sr in primary coolant water. Optimalization of measurements and analysis of potential interferences.
Sr-90 and Tc-99 are produced by the fission of U-235. Information on Sr, Tc and other fission and activation product content in the primary coolant and at various locations in the purification system can be of considerable value in assessing fuel integrity and performance of purification system component. Using inductively coupled plasma mass spectrometry (ICP-MS) for long-lived radionuclides improves detection limit and accuracy. However, in accurate measurements by ICP-MS method, the contribution of isobaric interferences from atomic- and molecular ions created by plasma gas and/or solvent used should be defined and appropriate ways of their elimination should be introduced. Also, to obtain accurate results in trace and ultra-trace analysis of Tc-99 and Sr-90, optimatization of measurements is necessary. In this work, the influence of different parameters (eg. sample flow rate, nebulizer type) on the strontium and technetium measurements have been taken into account. Acknowledgments: Research task No. 8 „Study of processes occurring under regular operation of water circulation systems in nuclear power plants with suggested actions aimed at upgrade of nuclear safety" partly financed by the National Research and Development Centre in the framework of the strategic research project entitled „Technologies Supporting Development of Safe Nuclear Power Engineering”.
Speaker: Ms Iwona Bartosiewicz (Institute of Nuclear Chemistry and Technology)
• 36
Application of the two-step approach to investigaion of chemical shifts and other electronic properties determined by core region of heavy atoms
Modeling of electronic structure and properties of actinide compounds is of considerable importance for modern radiochemistry. However, reliable and accurate estimates are a great challenge for quantum chemistry of actinides due to strong relativistic and correlation effects in such compounds. A development of theoretical approaches to this problem will stimulate application of a number of experimental techniques of analytic chemistry such as the method of chemical shifts in X-ray emission spectroscopy (XES). We report application of the theoretical method of generalized relativistic effective core potential [1] followed by the method of one-center nonvariational restoration [2] of valence electron wave function in the vicinity of heavy atoms to calculation of different properties of compounds containing heavy elements including actinides. Basing on the developed atom-in-compound (AiC) concept we demonstrate a possibility to use XES to control a number of properties that are determined by the core region of valence wavefunction. We show its applicability to provide a unified tool for indirect and independent accuracy check of the evaluated AiC characteristics. This is of great importance to the cases where an experimental check is difficult or even impossible [3]. The work is supported by the SPbU Fundamental Science Research grant from Federal budget #0.38.652.2013 and RFBR grant 13-03-01234-a. L.S. is also grateful to the President of RF grant no 5877.2014.2 and to the Dmitry Zimin Dynasty'' Foundation. 1. N.S. Mosyagin, A.V. Zaitsevskii, and A.V. Titov, Rev. At. Mol. Phys. 1, 63 (2010). 2. A.V. Titov et al., Int. J. Quant. Chem., 104, 223 (2005). 3. L.V. Skripnikov, A.N. Petrov, A.V. Titov, J. Chem. Phys. 139, 221103 (2013).
Speaker: Mr Leonid Skripnikov (St. Petersburg State University, Petrodvoretz, Russia; Petersburg Nuclear Physics Institute, Gatchina, Russia)
• 37
Characterization of multicrystalline silicon for photovoltaics by methods of neutron activation analysis
The improvement of solar cells by achieving higher efficiencies and lower production costs is getting more important because of the worldwide increase of photovoltaics as a renewable energy source. In this framework, the aim of DFG-Project HA 5471/4-1 (Department of Nuclear Chemistry, Johannes Gutenberg-University, Mainz, “Fraunhofer Institute for Solar Energy Systems” (ISE), Freiburg) is to optimize the methods of manufacturing and analysis of solar silicon. One manufacturing method is the directional solidification of raw and partly purified silicon (called “feedstock”). Based on their lower segregation coefficients, the impurities accumulate in the liquid stage during the solidification. The so produced silicon has acceptable concentrations of impurities and is called “solar grade silicon” (SoG-Si). For the analyses by means of Instrumental Neutron Activation (INAA) and Prompt Gamma Activation (PGAA) samples from SoG silicon as well as from highly purified silicon after the final solidification step are irradiated at three different research reactors: TRIGA Mainz, BR 2 Mol and FRM II Munich. Of special interest are the dopants boron and phosphorus and the 3d transition metals, which decrease the efficiency of solar cells by recombination of charge carriers. Profiles of these element concentrations in the produced silicon ingot as well as analyses of the impurity concentration in feedstock material and melting pot samples can help to improve the manufacturing method [1]. First results of measurements have shown a specific element distribution in produced silicon, caused by processes of diffusion and segregation [2]. Most of the elements, especially cobalt and boron, follow the Scheil-Equation [3] for distribution during directional solidification. With INAA the elements cobalt, iron, copper, chromium, antimony and scandium could be detected in silicon with a very low detection limit; with PGAA it was possible to measure boron at the ppb-level. [1] J. Hampel, F.M. Boldt, H. Gerstenberg, G. Hampel, J. V. Kratz, S. Reber, N. Wieh, Fast determination of impurities in metallurgical grade silicon for photovoltaics by INAA, Applied Radiation and Isotopes, 2011 [2] D. Macdonald, A. Cuevas, Transition-metal profiles in a multicrystalline silicon ingot, Journal of Applied Physics, 2005 [3] E. Scheil, Zeitschrift für Metallkunde, 1942
Speaker: Ms Barbara Karches (Department of Nuclear Chemistry of Johannes Gutenberg-University of Mainz, TRIGA)
• 38
Determination of 3H, 36Cl, 22Na, 85Sr and 133Ba by means of precipitation method
Spent nuclear fuel from the nuclear power plants owned by TVO (Teollisuuden Voima Oy) and Fortum, is planned to be disposed at a repository at a depth of more than 400 meters in the bedrock of Olkiluoto (Eurajoki, Finland). The repository system includes multiple release barriers: the nuclear fuel, copper canister with a cast iron insert, bentonite buffer around the canister and backfilling of the tunnels. Furthermore, the surrounding rock is the last barrier if the man-made barriers fail during the passage of time. Safe disposal of spent nuclear fuel requires information about the radionuclide transport and retention properties within the porous and water-containing rock matrix along the water conducting flow paths. The second in-situ experiment within ONKALO, the underground rock characterization facility in Olkiluoto, as part of the project “rock matrix REtention PROperties” (REPRO) was performed during 2013 using 3H, 36Cl, 22Na, 85Sr and 133Ba as tracer nuclides. The aim is to study the diffusion and sorption properties of nuclear compounds in the rock matrix under real in-situ conditions. A straightforward way to investigate properties of rock matrix under in-situ conditions is to carry out a water phase matrix diffusion experiment (WPDE2) in a two-meter artificial flow channel along the perimeter of the drillhole. The volume and aperture of the flow channel are minimized by an impermeable cylindrical flow guide inside the packer system. The inlet and outlet positions of water are located at the opposite ends of the packed-off section. WPDE2 tracer test is performed using a slow flow rate that is generated using a piston pump. The experiment is executed using synthetic groundwater to carry the tracer solution. This work presents the determination of radionuclides activities from the WPDE2 experiment giving the breakthrough curves of the radionuclides as a result. Rapid and precise determination of 3H, 36Cl, 22Na, 85Sr and 133Ba is of vital importance in the project. The activity of 22Na, 85Sr and 133Ba can be measured using gamma detector. Due to their electron emissions 22Na, 85Sr and 133Ba disturb the LSC measurement of 36Cl and 3H. So it is essential to seek a simple, convenient way to separate these radionuclides before spectrometric analyses. From the initial water sample 22Na, 85Sr and 133Ba are measured by gamma spectrometry first. Then NaCl carrier is added in solution. AgCl precipitation is produced and Ag(NH3)2Cl solution is measured with liquid scintillation analyzer to obtain the 36Cl activity. Sr(NO3)2 and Ba(NO3)2 carriers are added to the supernate and 85Sr and 133Ba are precipitated as carbonates; SrCO3 and BaCO3. This supernate contains 3H and 22Na and remains of 85Sr and 133Ba. Gamma emitting nuclides are measured first and then 3H with liquid scintillation analyzer. 22Na, 85Sr and 133Ba disturb the counting of LSC measurement. Thus using the quench curves determined for each of gamma emitting nuclides in 3H window of LSC, the amount of counts from the disturbing nuclides in 3H window can be calculated and reduced from the actual 3H counts. Then the “clean” 3H activities are determined by using the 3H quench curve. The separation procedure is optimized. The recovery of 36Cl is about 100% as well as the recovery of 85Sr while the recovery of 133Ba is slightly less, being about 85%. The detection limit for 3H in this solution is 1Bq/g. The precipitation procedure is easy and fast to separate 36Cl from the solution. 85Sr and 133Ba can be removed from the solution by carbonate precipitation in a way that 3H is measurable.
Speaker: Dr Lijuan Qian (Lanzhou University)
• 39
Determination of distribution coefficients of 134-Cs from Baltic Sea water using Cs-selective sorbents.
Radiocaesium is one of the most important radionuclides introduced into natural environment by human activity. In spite of its small concentration 137Cs and 134Cs may cause serious hazard in case of spread of fission products in the air or contamination water reservoirs. This risk is a result of high radioactivity and long decay time of mentioned radioisotopes. Decontamination of fresh or salty water needs special handling as a result of specific properties of caesium ions. Unlike to transition metals, caesium does not create insoluble precipitates and is weakly sorbed onto conventional cationic ion exchangers. Highly selective sorbents are used for that purposes. The most frequently used sorbents are titanates and silicotitanes, transition metal(II) hexacyanoferrates(II) and heteropolyacid salts. The minor role plays zeolites and natural organic sorbents. According to the Polish energy policy for the next two decades commissioning of two nuclear power plants is expected. In this poster a results of the determination of distribution coefficients of 134Cs from Baltic Sea water using commercially available and synthesised in a laboratory scale Cs-selective sorbents are presented. Comparison of these values may be important not only as an analytical purposes of radionuclide preconcentration, but also simulates decontamination of large volume salty water as a potential result of radioactive leakage. The research has been executed as a part of research task No. 8 „Study of processes occurring under regular operation of water circulation systems in nuclear power plants with suggested actions aimed at upgrade of nuclear safety" financed by the National Research and Development Centre in the framework of the strategic research project entitled „Technologies Supporting Development of Safe Nuclear Power Engineering”.
Speaker: Dr Krzysztof Borowik (Institute of Nuclear Chemistry and Technology)
• 40
Determination of Strontium Radionuclide Using Flow-Injection Analysis with ICP-MS Detection
Flow analysis is considered an efficient and universal technique of analytical science. Its wide range of advantages as compared to other known techniques is the argument for its increasing use. Thus, there may be distinguished a simple apparatus construction, which provides low sample use, together with an opportunity to implement many measurement concepts which are not always possible to achieve with common laboratory methods. Generally, this is understood as a variety of system constructions which are adapted to the analysts’ ideas and can assure that a sample in the flow is processed chemically i.e. by derivatization, even by multistage reactions, and also physically, for example by sample preconcentration. Another facility of the flow analysis is its automation ability, which means a full control over the fluid flow, its volumes, flow rates and timing. The main objective of the study is to develop and apply flow systems based on MSFIA - LOV (Multi-syringe flow injection analysis—Lab-on-Valve) to radioanalysis of strontium-90 in reactor coolant samples. The initial stage of research is to optimize the method of mechanized processing of samples. What is worth to remark, is that the construction of the system has been miniaturized enough to allow all the processes of sample preparation to take place in a several centimeters big reaction valve (LOV). The analytical procedure included a couple of stages—firstly, the column in the LOV was loaded with Sr-resinTM and conditioned. In the further stages, a sample was injected and its proceeding—the separation and concentration—took place in the LOV. The proposed analytical procedure included also the elimination of interferences from the elements disturbing detection (with similar affinity to Sr-resin i.e. Ba and isobaric interferences of 90Sr) as well as from the elements present in the coolant (boric acid). The optimization of the process included: selection of the solution and its volume to elute the retained strontium on a column with Sr-resin, the selection and optimization of the solution volume for the elution of interfering elements. The results of optimization were checked by using inductively coupled plasma mass spectrometry (ICP MS). The wide scale of implementation of this technique to monitoring and determination of radionuclides is a promising idea esspecialy for continuous monitoring of radionuclides in the reactor coolant.
Speaker: Ms Kamila Kołacińska (Institute of nuclear chemistry and technology)
• 41
Determination of U,Pu, Am /Cm Isotopes in Ash Resulted from the Incineration of NPP Cernavoda Low Level Waste
For the waste management characterization of radionuclides inventory is required. This work presents the method and the results for determination of U, Pu and Am/Cm isotopes in the ash resulted from the incineration of NPP Cernavoda, (Romania) low level activity waste, in order to have accurate information regarding the alpha emitting radionuclide content and a proper classification (LLW, ILW)of the waste. The sample is traced with U-232, Pu-242 and Am-243, then is decomposed in an open microwave digestion system by a mixture of a strong acids and peroxide. Hydrofluoric acid is used for destruction of silicates. Hydrofluoric acid is eliminated by addition of nitric acid several times. The residue is dissolved in nitric acid and aluminum nitrate solution. Uranium, Plutonium and Americium/Cm isotopes are separated from each other and from other radionuclides and matrix constituents by extraction chromatography . Two columns with UTEVA and TRUE Eichrome resine were used for separation .The sample solution is passed first through UTEVA resin that retains U isotopes, then loading and rinsing effluents are passed through TRU resin that retains Pu and Am/Cm isotopes. A redox adjustment of Pu was done before passing through UTEVA column using Fe(II) and NH2OH . HCl , and also into the TRU column using NaNO2. Ascorbic acid was used to reduce Fe(III) to Fe (II) in order to prevent the uptake of Fe (III). Uranium was eluted from UTEVA with diluted hydrocloric acid, americium is eluted from TRU with hydrocloric acid and plutonium is eluted from TRU with amonium bioxalat. The sample preparation for alpha spectrometry was done by cerium carrier co-precipitation. Alpha spectrometry of measurements were performed by Ortec Alpha Spectrometer System. average tracer recovery was about 50,6% for Uranium, 43,7% for Plutonium and 54,1% for Americium
Speaker: Mrs Adina Sandru (MATE-FIN srl)
• 42
Determination of Uranium Isotopes Composition Using LSC
Fast, simple and effective method for determination of enrichment/depletion of uranium samples that can be used not only in the laboratory but also for unknown samples at inspections outdoors, it is for longer time in insistent demand of specialists. The technique of liquid scintillation counting (LSC) in the mobile mode represented by Triathler LSC Counter (Hidex Oy) could be a valuable tool for this type of measurement. Application (usage) of this equipment allows several advantages: determination of enrichment/depletion under off-road conditions, combination of alpha, beta and Cherenkov counting (gives a complete picture required), milligram or even sub-milligram amounts of the sample (comparing e.g. to gamma-ray spectrometry), and easy preparation of the sample by mixing of U-salt with scintillation cocktail (comparing to e.g. alfa-spectrometry). The method can be used as the final step of suitable separation/concentration method. The method was also adjusted as a task for students in “Practical exercises in radiochemistry techniques” in the educational programme “BSc in Nuclear Chemical Engineering”.
Speaker: Dr Kateřina Čubová (CTU FNSPE, katedra jaderné chemie)
• 43
Development and application of method for determination of 89,90Sr in environmental samples by the use of NaOH for separation of strontium from calcium
The method allows cheap, safe and reliable determination of 89Sr and 90Sr in major environmental materials in sizeable quantities – water (500 L), soil (1000 g), milk (20 L), grass (1000 g), bone (1000 g), etc., routinely or in emergency situations (nuclear power plant accidents, “dirty” bombs, nuclear weapons detonation, etc.). Radiostrontium is leached by aqua regia from the ashes of the solid samples (burned at 5500C) or it is preconcentrated from the liquid samples by carbonate precipitation. The separation of strontium from the large quantities of calcium is atained by the use of NaOH – under heating or at room temperatures. Due to difference of solubility of strontium and calcium hydroxides in diluted alkaline solution (0.2-0.3M NaOH) calcium hydroxide can be precipitated while strontium hydroxide remains in the solution. When both 89Sr and 90Sr should be reported radiostrontium is separated from the isotopes of barium/radium/lead by precipitation of the latter as chlorides in hydrochloric acid. Otherwise when only 90Sr is expected to be present in the samples then separation (after ingrowth) of its daughter nuclide 90Y (from 90Sr and isotopes of barium/radium/lead) is carried out in sulfate and ammonium hydroxide media. Measurements are performed by liquid-scintillation spectrometer in Cherenkov mode (without scintillation cocktail) of purified 89,90Sr or purified 90Y. Chemical yields of strontium and yttrium is measured respectively by gamma-spectrometry (of 85Sr-tracer) and by titration (of stable yttrium carrier). The critical steps in the method were examined which resulted in reproducible chemical yields in the range 75 – 95%. The method has been used routinely at 2 laboratories in Bulgaria for analyses of more than 1000 samples in the last 7 years. The analytical quality was checked by analyzing reference materials with different matrices and regular participations in international intercomparisons. References: 1. Popov L, Hou X, Nielsen SP, Yu Y, Djingova R, Kuleff I (2006) J Radioanal Nucl Chem 269:161-173. 2. Popov L, Mihailova G, Hristova I, Dimitrova P, Tzibranski R, Avramov V, Naidenov I, Stoenelova B (2009) J Radioanal Nucl Chem 279:49-64. 3. Chen Q, Hou X, Yu Y, Dahlgaard H, Nielsen SP (2002), Anal Chim Acta 466:109-116. 4. Patti F, Hernandez A (1971), Anal Chim Acta 55:325-. 5. Chang TM, Chen SC, King JY, Wang SJ (1996) J Radioanal Nucl Chem 204:339-347.
Speaker: Dr Lyubomir POPOV (KOZLODUY NPP, Bulgaria)
• 44
Development and validation of robust analytical method for determination of Cr-51 in blood samples by LSC
Cr-51 is a radioactive isotope of chromium having a half-life of 27.7. The decay scheme indicates that 91% of the time, Cr-51 decays by electron capture directly to the ground state of the V-51 and emitting no gamma rays at all. Only 9% of the time the Cr-51 decays directly to the excited state of the daughter (V-51m), which then further decays by isomeric transition to the ground state, emitting a 320 keV gamma ray during the process. At the present, Cr-51 is used in many application fields, in particular, in medicine, where, thanks to its chemical properties, Cr-51 has found to be an excellent tool for the labeling of red blood cells in order to measure of mass or volume, survival time, and sequestration studies, for the diagnosis of gastrointestinal bleeding, and to label platelets to study their survival [1]. Nowadays, for the determination of C-51 activity in blood samples, usually, the conventional -spectrometry is applied [2]. In spite the fact that the method utilise almost no (or minimum) sample preparation steps, the careful attention for the calibration geometry should be paid. For instance, the calibration should be performed with the homogenised calibration standard (that is by blood samples is not always easy). On the other hand, the limit of detection, achieved by -spectrometry (depending on the type of detectors) are normally in the range of 10 Bq/g and relatively long counting times are required. However for some clinical studies, where the incorporated doses are sometimes restricted, a method with better detection capability would be absolutely preferable. Because of the electron capture decays the Cr-51 could be also detected using the Liquid Scintillation Counting [3]. Due to its simplicity, sensitivity and relatively simple sample preparation, this method was proved to be a suitable alternative for -spectrometry in order to determine the Cr-51 in blood samples. To prove this in the present study we developed a robust analytical method for measurement of Cr-51 in blood samples in routine mode by means of LSC. The method was validated with the synthetically prepared blood samples from different subjects. Prior to the measurements the samples were microwave digested in order to eliminate the matrix influence. The figures of merits, such as sensitivity, limits of detection and quantifications, precision and accuracy were studied and confirmed the capability of the method to determine the Cr-51 in blood samples in the range of 0,5 Bq per g of sample. All the results will be presented and discussed in details in the frame of current poster presentation. 1. Vandermeulen, E, et al. (2010). "Determination of optimal sampling times for a two blood sample clearance method using Cr-51-EDTA in cats ". Journal of Feline Medicina and Surgery 12: 577 2. Moreira D, et al. (2009). Determination of Cr-51 and Am-241 X-ray and gamma-ray emission probabilities per decay. Applied Radiation and Isotopes 68: 596. 3. Sheppard, G (1971), The Simultaneous measurements of Cr-51 and C-14 by Liquid Scintillation Counting International Journal of Applied Radiation and Isotopes, 22: 125
Speaker: Dr Myroslav Zoriy (Reserch Center Jülich)
• 45
Development of an in-situ radiotracer method to measure the adsorption phenomena of different alpha-emitters
The so called in-situ radiotracer methods are widely used for the determination of charge- and mass transport on the liquid-solid interfaces. With these methods different phenomena can be investigated, such as adsorption, corrosion, contamination or decontamination. Each technique is based on the thin layer principle of Aniansson, which claims, that the adsorbed amount of a radioactive isotope with soft radiation can be measured with low background noise in case of proper cell arrangement. In the past decades several methods were developed to measure the adsorption phenomena of different beta and soft gamma emitting isotopes in-situ (36Cl, 35S, 32P, 51Cr, 110mAg, etc.), but none for the alpha emitters. The alpha radiation measurement technique is extensive, several measurement methods have been developed to measure both intensity and spectroscopic parameters. However, the existing methods are not capable to measure under in-situ conditions, most of them are presume vacuum technique, in which case a continuous contact with the solution is not possible. To determine the adsorption of alpha emitters under in-situ conditions on compact surfaces development of a new technique is necessary, which is the aim of this work. The main steps of the research and development project are: • Selection of the proper detection technique • Design a cell construction, which fits the Aniansson principle • Preparation of a high activity pure alpha source • Calibration of the cell • Determine the main equations • Measure the adsorption phenomena of different alpha emitting isotopes This research was supported by the European Union and the State of Hungary, co-financed by the European Social Fund in the framework of TÁMOP 4.2.4. A/2-11-1-2012-0001 ‘National Excellence Program’.
Speaker: Mr Dávid Horváth (University of Pannonia, Institute of Radiochemistry and Radioecology)
• 46
Elemental determinations in biological and environmental sample using PGNAA facility at Dalat Nuclear Research Institute
In this paper we present the results of determination of element concentrations in biological, environmental samples by using PGNAA facility which was installed at channel No. 4 of Dalat research reactor. The biological standard samples, Bovine Liver NBS 1577a and Rye Grass BCR 281 and environmental standard samples, Coal Fly Ash NBS 1633a were analyzed to verify the analytical ability of the facility. After that, the concentrations of C, N, S, K, Cl in biological samples and concentration of Al, K, Ti, Mn, Fe, Ca, Gd, Sm, Cd and Si in environmental samples were determined. The detection limits of the above elements were also investigated.
Speakers: Mr Canh Hai Nguyen (Nuclear research institute), Prof. Huu Tan Vuong (Viet Nam Agency for Radiation and Nuclear Safety), Prof. Nhi Dien Nguyen (Nuclear Research Institute)
• 47
Fast procedure for self-absorption correction for low γ energy radionuclide Pb-210 determination in solid environmental samples
Speaker: Dr Magdalena Długosz-Lisiecka (Technical University of Lodz, Faculty of Chemistry)
• 48
Implementation of calculation codes for corrections of systematic effects in measurement laboratories
A vast number of papers are reporting on the development of calculation codes for corrections of systematic effects in gamma spectrometry. Many comparison studies have also been performed where differences and similarities between many of those calculation codes are presented. However, most studies performed in this area are performed for the experienced user or program developers. Despite the high quality of those papers and the important information about the calculations codes, when selecting, implementing and using these codes at different laboratories regular users are often struggling with other issues. This study aimed at considering a user perspective for correction of common systematic effects within gamma spectrometry that measuring laboratories are facing in their daily work. A coincidence free calibration was established for a volume source at an endcap position by characterising the detector geometry using the calculation code VGSL (Virtual Gamma Spectrometry Laboratory). Furthermore, four different calculation codes (ANGLE, EFFTRAN, GESPECOR and VGSL) were compared by calculating corrections factors for true coincidence summing (TCS), fill degree in the sources and new source-detector geometries. Two of the calculation codes are simulation codes and two are semi-empirical codes. The detector model was optimized with VGSL and thereafter the same model was used in the other softwares. There are differences in how the correction factors are calculated in the calculation codes, by Monte Carlo simulation or efficiency transfer. Also the degree of details of the detector and source parameters that can be entered varies between the codes. Within the scope of the investigations in this study this has not shown any effects on the results. Furthermore, despite the fact that the detector model only was optimized with one of the calculation codes no clear differences could be observed as a result from this. The uncertainty of the TCS corrected activities were found to be in the same magnitude as the certified activities in the reference solution itself. When activities were corrected for different filling degrees in the sample sources the deviations from the certified reference solution were generally lower than 5%. Larger deviations were observed, around 10% or less, when activities were corrected for new source-detector geometries. Discrepancies between 5 and 10% are often considered to be acceptable for some applications, i.e. environmental or survey monitoring. This is an important knowledge for cases when it can be motivated to calculate corrections for other source-detector geometries. However, measurements should preferably be performed in source-detector geometries closely resembling the calibration geometry since those corrected activities are associated with lower uncertainties. The user should carefully select the proper calculation code that will cover the need of the measurements that will be performed, i.e. if TCS corrections are needed and what detectors and sources will be used. When implementing the calculation code at the measuring laboratory it is of greatest importance to validate the calculations and thereby identify within what boundaries the corrections are valid. It can be concluded that all the investigated calculation codes in this study are robust and will give reliable measurement results.
Speaker: Dr Sofia Jonsson (1) Swedish Defence Research Agency, FOI, division of CBRN Defence and Security, SE-901 82 Umeå, Sweden)
• 49
In-beam neutron activation analysis at FRM II, Garching
The thermal equivalent neutron flux at the prompt gamma activation analysis (PGAA) facility at the Forschungsneutronenquelle (FRM II) at Garching, Germany is 6x1010 cm–2 s–1 which is the highest beam flux reported. This beam intensity is already strong enough to activate samples for the purpose of neutron activation analysis (NAA), too. This option has been used together with PGAA simply performing decay counting after switching off the beam using the same spectrometer used for the in-beam measurement, and proved to be useful in the case of a handful of elements, like Na, Mn etc. The main advantage of in-beam activation is that the beam contains no epithermal or fast neutrons, thus realizing activation in its purest form. Many elements, like Al, Sb, or Ge could not be analyzed in this way, because they appear in the spectral background. Recently, a low-background counting chamber has been installed a few meters away from the PGAA instrument using a 30-% HPGe detector equipped with a mechanical cooler and covered with 10 cm of lead, boron and lithium-containing sheets against neutrons and tin to attenuate lead x-rays. The background conditions are much better for this spectrometer, at the same time the counting efficiency is also higher. This enables us to analyze a larger number of elements off-line. The first results will be presented at the conference.
Speaker: Dr Krzysztof Kleszcz (Technische Universität München, Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II))
• 50
Innovations at the MT-25 microtron aimed at applications in photon activation analysis
Speaker: Jiří Mizera (Nuclear Physics Institute, Academy of Sciences of the Czech Republic)
• 51
Innovative technique for rapid measurement of post-accidental 89Sr in water: use of the Cerenkov Effect combined with color quenching
Many techniques have been developed in the interest of measuring radionuclides activity concentration in environment in case of a nuclear accident. Some so called “crisis” techniques are currently under development at the Institut de Radioprotection et de Sûreté Nucléaire in France in order to rapidly measure radioactive isotopes of interest and provide information to the authorities. Especially, strontium 89 and 90 can be radioactive isotopes of interest. They are both pure beta emitters. Because of their toxicity and the similarity of their physical and chemical behavior with calcium, these elements may be found through the food chain. Strontium 89 has a half-life of 50.5 days and can reach an activity concentration 10 to 170 times higher than strontium 90 in case of accidental reject. After the Fukushima accident, the necessity of quantifying rapidly strontium 89 and 90 appeared. It is therefore essential to measure their activity concentration in the environment [1]. The technique we are going to present concerns the determination of the activity concentration of strontium 89 and 90 in water, according to the 89Sr/90Sr ratio. It consists of two stages: the chemical separation by ionic chromatography and the measurement of the activity concentration of strontium 89 and 90 with a liquid scintillation counter. The automated separation is performed from the adaptation of an existing ionic chromatography, whose features are not to measure cations but to separate and isolate strontium. It is important to understand that right after the isolation of strontium, the decay product of 90 strontium (yttrium 90) will grow instantly. The measurement step is also singular because of the use of Cerenkov Effect on a quenched sample. The quenching is realized by applying a thin colored film on the sample vial. As beta particles energy of strontium 90 is low for Cerenkov Effect (540 keV), its counting efficiency is very low. The colored quench is therefore used to make disappear the number of counts on the spectrum caused by strontium 90. This way, yttrium 90 ingrowth and strontium 89 decay are exclusively measured (E90Sr < E89Sr < E90Y). Successive countings and modeling of the ingrowth/decay kinetics allow us to evaluate the activity concentration of strontium 89, and 90 depending on the 89Sr/90Sr ratio. The results we are going to present at Radchem 2014 concern the development of the chemical separation by ionic chromatography and measurement of strontium by Cerenkov Effect. Studied parameters such as the quenching parameter to use, the sample geometry and the influence of 89Sr/90Sr ratio will be discussed. Results on proficiency test samples and standard solutions will also be shown. At last, an estimation of the total analyzing time comprising the separation and measurement steps will be given. [1] Tovedal A, Nygren U, Ramebäck H. Methodology for determination of 89sr and 90sr in radiological emergency: i. scenario dependent evaluation of potentially interfering radionuclides. J Radioanal Nucl Chem 2009, 282(2), 455–459.
Speaker: Dr Kevin Galliez (IRSN)
• 52
Instrumental Neutron Activation Analysis for the Determination of Gold Nanoparticles in Mice Tissues
Gold nanoparticles (GNPs) have been utilized in high technology applications such as organic photovoltaics, sensory probes, therapeutic agents, drug delivery in biological and medical applications, electronic conductors and catalysis. GNPs for use as molecular imaging probes and their biodistribution in safety reason have been studied, widely and intensively. The objective of this study was to evaluate the capability of neutron activation analysis (NAA) method to determine GNPs in mice tissues and biological samples. 10 nm GNPs were instilled into a mouse and eleven tissue and biological samples such as blood, bone, brain, gonad, heart, intestine, kidney, liver, lung, spleen and stomach were prepared for NAA. The prepared sample was irradiated for 10 minutes with thermal neutrons using the Pneumatic Transfer System (PTS) at the HANARO research reactor in the Korea Atomic Energy Research Institute (KAERI). Acquisition of the gamma-ray spectrum was carried out using a high purity Ge detector coupled to DSPECPLUS. Intravenously administered GNPs were detected only in the liver and spleen samples. On the contrary, orally administered GNPs were detected in the stomach and intestine samples. High amount of Na in the samples hampered the detection of GNPs and minimum detection limit for GNPs in these samples was approximately 0.01 mg/kg.
Speaker: Mr JongHwa MOON (Korea Atomic Energy Research Institute)
• 53
Instrumental photon activation analysis with the MT-25 microtron
Instrumental photon activation analysis (IPAA) is a useful and complementary method to instrumental neutron activation analysis (INAA). IPAA allows determination of number of elements not determinable by INAA, and determination of many elements with a better sensitivity than INAA. Unlike INAA based mainly on the neutron capture reactions (n,gamma), PAA is based on photonuclear reactions, particularly photodisintegration reactions (gamma, n) and (gamma,p), and photoexcitation reactions (gamma,gamma’). These reactions take place only at photon energies exceeding a threshold. This can be utilized in optimizing beam energy at irradiation of a specific sample, when partial suppression of interfering nuclear reactions can be achieved by keeping the maximum photon energy below or only slightly above their threshold. Particularly in analysis of geological samples (minerals and rocks), this reduces substantially, compared to INAA, matrix effects hindering determination of trace elements. Higher penetration of high energy photons and lower activities produced allow also analysis of larger samples. An effective source of the high energy photon radiation for use in IPAA is the secondary radiation - bremsstrahlung - produced at deceleration of electrons accelerated in a high frequency cyclic accelerator - microtron. The MT-25 microtron built at the Czech Technical University in Prague in the late 1980s, after its takeover and modernization by the Nuclear Physics Institute ASCR in the years 2003-2005, has been utilized regularly for purposes of IPAA. Until recently, IPAA analyses could be carried out only in an offline regime, i.e., in assay of elements providing by photoactivation radionuclides with half-lives long enough for counting with a sufficient count yield even after decay time elapsed between switching off the microtron and manual delivery of sample to a detector. Currently, installation of an automated pneumatic system for rapid sample transport between the beam position and detector in an online regime is being completed which will, regarding numerous short-lived products of photonuclear reactions, provide substantial extension of the analytical range of IPAA. The contribution presents possibilities and recently realized examples of utilization of IPAA with the MT-25 microtron, namely a recently developed and optimized procedures for fast fluorine and nitrogen assay, and their application in analysis of various materials. The work has been supported by the projects 13-27885S and P108/12/G108 of the Czech Science Foundation.
Speaker: Mrs I. Krausová (Nuclear Physics Institute ASCR)
• 54
Investigation of hydrophilic materials as hypoxic phantoms
Cross-linked hydrophilic co-polymers are candidates for use as phantom materials because they can be modified to have similar elemental compositions to that of body soft tissues. Co-polymers contain both hydrophobic and hydrophilic monomers; the molar ratio of which allows the water-uptake ability to be controlled. By controlling the hydration level, it may be possible to imitate various types and different disease stages of tissues, as well as the extent of tissue hypoxia. A series of experiments was carried out for different types of cross-linked hydrophilic co-polymers; hydroxyethyl methacrylate/Vinyl pyrrolidone (HEMA-VP) and methyl methacrylate/Vinyl pyrrolidone (MMA-VP) were hydrated by biological fluids with or without the reducing agent AnaeroGen to obtain hypoxic condition or normoxic condition; respectively. The relative yield of 3γ-to-2γ annihilation photons was determined using the positron emitter, Na-22, with a lanthanum bromide:Cerium (LaBr3:Ce[5%]), scintillation detector. The peak-to-peak method was used to calculate the ratio of the full-energy photopeak area of the 511keV annihilation obtained in the sample and the aluminium reference material. The Na-22 source used has a positron yield of 90.4% and a gamma-ray energy at 1274keV of relative intensity 99.9%, emitted almost simultaneously. The energy resolution and the intrinsic photopeak efficiency figures for LaBr3:Ce were (3.37±0.08)% and (29.1±0.8)%, respectively for the 511keV annihilation energy. The relative yield of 3γ-to-2γ annihilation photons was calculated and discussed in different hydrophilic co-polymers.
Speaker: Dr M Alkhorayef (Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH, UK)
• 55
Natural radionuclide extraction from aqueous solutions by ionic liquids
Natural radionuclide extraction from aqueous solutions by ionic liquids Gabriele Wallner, Orhan Sap, and Regina Krachler Institut für Anorganische Chemie, Universität Wien, Währingerstr. 42, A-1090 Wien, Austria e-mail: gabriele.wallner@univie.ac.at Abstract Ionic liquids (ILs) are salts with a low melting point (below 100 °C) and they are composed of completely dissociated ions. ILs have many advantages and they are of growing interest in the field of green chemistry. Most of the commonly used ILs are composed of large organic cations and the basic compounds consist of e.g. imidazolium, pyridinium, pyrrolidinium, ammonium and phosphonium(1). Some of the unique properties of the most widely studied ILs include the large liquid temperature range, high thermal stability, electrical conductivity, and tunable physical properties. Especially the extraction of uranium by using ILs is of enduring interest in the literature as it may also be relevant to spent fuel reprocessing.(4,5) The presented work is part of a project dealing with purification processes for drinking water. The aim of our work was the extraction of Uranium, Radium and Polonium from aqueous solutions with an IL as well as its back extraction (Pb-210 has not been taken into account here as it is removed together with stable lead). Especially the conventional anion exchange step for uranium separation from water (or other sample matrices) is very time consuming (pre-concentration and column chromatography), while the liquid-liquid extraction into an IL also takes its time, but can be done by automated systems. Investigations in our laboratory a few years ago demonstrated that extraction of uranium from water is possible with [A336][TS]2,3, tricaprylmethylammonium thiosalicylate. The ILs under investigation now are [A336][MTBA], tricaprylmethylammonium 2-(methylthio)benzoate, as well as [Mal][A336], [Thiom.][A336], [Mal][Cyphos], [Thiom.][Cyphos], [A336][Ant], [PR4][Ant], [A336][DBA], [PR4][DBA]. Investigations were performed with an artificial uranyl nitrate solution of a known amount of uranium (e.g. a few µg U in 10 ml diluted nitric acid) and mixed with the respective ILs. After centrifugation the phases were separated and the aqueous phase was analysed by liquid scintillation counting (LSC) to ensure that the uranium was removed. Afterwards acids of different molarity or EDTA solutions were used for back extraction of uranium from the organic phase. For the investigation of the other nuclides, water samples with known amounts of Ra and Po were used (reference samples or mineral waters). For application in the field of drinking water purification we searched also for immobilisation of the ILs on a suitable backing material. Our goal is to find a new method to shorten and simplify the chemical procedure for the determination of radionuclides (especially uranium) in natural (water) samples as well as to look for a new purification method for drinking water supplies. [1] Violina A. Cocalia, Keith E. Gutowski, Robin D. Rogers, Coordination Chemistry Reviews, 250, 2006, 755- 764. [2] Daniel Kogelnig, Anja Stojanovic, Markus Galanski, Michael Groessl, Franz Jirsa, Regina Krachler, Bernhard K. Keppler, Tetrahedron Letters 49, 2008, 2782-2785. [3] Michaela Srncik, D. Kogelnig, A. Stojanovic, W. Körner, R. Krachler, G. Wallner, Applied Radiation and Isotopes 67, 2009, 2146-2149. [4] James E. Quinn, M.D. Ogden, K. Soldenhoff, Solvent Extraction and Ion Exchange 31, 2013, 538-549. [5] Dimitrios Tsaoulidis, V. Dore, P. Angeli, N.V. Plechkova, K.R. Seddon, Chemical Engineering Journal 227, 2013, 151-157.
Speaker: Prof. Gabriele Wallner (Institut für Anorganische Chemie, Universität Wien)
• 56
Neutron Activation Analysis of Children’s Hair from Altai Republic
The study focuses on the chemical composition of human hair as an indicator of the level of income of the chemical elements in the human body and its impact on growth and development of children and teenages in the local geochemical conditions. Neutron activation analysis (NAA) was used to analyze 186 samples of hair of children from four villages of Altai Republic. Data for 54 boys and 132 girls in the age of 7 to 17 were analyzed. Significantly higher content of sodium, aluminum and chlorine was observed in the hair of boys over girls. The following short-lived isotopes were determined: Na, Mg, Al, S, Cl, K, Ca, V, Mn, Cu and I. Concentrations of magnesium and calcium were significantly higher in the hair of girls. Iodine, copper, manganese and sulfur concentrations in the hair of boys and girls are close to each other, the differences between the sexes are not significant. Median concentrations of the studied elements in the hair of boys and girls were, respectively: Na – 75 и50; Mg – 49 и62; Al – 21 и13; S – 41150 и39850; Cl – 1020 и390; Ca – 608 и973; Mn –1,1 и0,82; Cu – 9; I – 0,2 mg/g. It was shown that the high content of calcium and magnesium is observed in the hair of children living in rural areas with high hardness and salinity of drinking water. Iodine concentrations in the hair of studied cohort of children is low, especially in puberty.
Speaker: Ms Zoya Goryainova (Joint Institute for Nuclear Research)
• 57
Nuclear analytical merthods for studying elemental composition of calciofied tissuers
Various nuclear activation techniques have been developed and applied to determine the elemental composition of calcified tissues (teeth and bones). Fluorine was determined by prompt gamma activation analysis through the 19F(p,a)16O reaction. Carbon was measured by activation analysis with He-3 ions, and the technique of Proton-Induced X-¬ray Emission (PIXE) was applied to simultaneously determine Ca, P, and trace elements in well-documented teeth. Dental hard tissues: enamel, dentine, cementum, and their junctions, as well as different parts of the same tissue, were examined separately. Furthermore, using a Proton Micro-probe, we measured the surface distribution of F and other elements on and around carious lesions on the enamel. The depth profiles of F, and other elements, were also measured right up to the amelo-dentin junction. A new technique has been developed for studying the depth profiles of F in teeth, non-destructively, to larger depths than hitherto known. It is further shown that using this technique depth profile of any element/isotope can be determined non-destructively as long as the reaction cross sections of the particular nuclear reaction are available. Some results on the microscopic spatial distributions of various elements in kidney stones, using the powerful technique of Laser-Ablation Inductively-Coupled Plasma Mass Spectrometry (La-ICP-MS) are also presented.
Speaker: Prof. Mohammad Anwar Chaudhri (Institute of Biopphysics, Center for Medical Physics and Technology, University of Erlangen-Nuernberg, Erlangen, Germanyrnberg, Germany)
• 58
On the development of a rapid method for the determination of Pb-210 in water samples based on TK100 Resin
The crown-ether based SR Resin is frequently used for the separation and determination of Pb-210 in aqueous samples via liquid scintillation (LSC) or gas proportional counting (GPC). The resin only shows significant Pb (and Sr) retention at moderate to high acid concentrations; it does thus not allow for direct loading of Pb from acidified or raw water samples, making the additional use of pre-concentration steps such as ion exchange or co-precipitation necessary. In order to simplify and quicken the Pb-210 determination an extraction chromatographic resin (TK100 Resin) allowing the direct load of Pb from water samples and its subsequent purification on the same resin has been developed and characterized. The TK100 Resin is based on the crown-ether also used in the SR Resin; accordingly its selectivity and robustness against interferences from common matrix elements, such as e.g. Ca and Mg, are similar to that of the SR Resin. However, by including HDEHP into its composition Pb can now be extracted at a much wider range of pH conditions, i.e. pH £8. Conditions allowing the removal of other beta emitters (e.g. Sr-90, Bi-210, Y-90) from the resin, and for the final elution of Pb from the resin, have been identified. Elution studies have been performed with the resin in column form as well as in disc form, the latter having the advantage of allowing higher flow rates. It could be shown that Pb uptake was very high even at elevated flow rates (e.g. 10 mL/min for columns and 30 mL/min for discs). The new rapid method was tested on spiked tap water samples. Samples of up to 5 L were directly loaded onto the resin in column or filter geometry at elevated flow rates; Pb was retained on the resin, purified and finally eluted with high chemical yield and purity. The direct measurement of Pb-210 loaded discs by liquid scintillation counting is being evaluated in order to further speed up the method.
Speaker: Dr Steffen Happel (TrisKem International)
• 59
Performance Evaluation (PE) Samples as Part of Laboratory Quality Control.
Role of PE samples in the Laboratory Quality control is briefly discussed. Eckert & Ziegler Analytics (EZA) capabilities are outlined. New Fission products Mixture (FM) is introduced. This mixture of radionuclides represents real fission products resulted from the irradiation of natural or enriched Uranium with thermal neutrons. Analysis of this mixture is real challenge and it can be very valuable tool for training and proficiency testing. Fission mixture has several advantages over existing EZA activation/fission mixture: - FM contains same array of radionuclides as post-accident samples, - Over 20 isotopes with reasonable half-lives can be certified, - Liquid FM samples can test laboratory ability to handle samples properly prior to analysis. Improper sample container, preservation, storage conditions etc. can significantly alter analytical results. - Gamma spectrometry of this mixture requires extensive knowledge of the methodology and particularly the correct application of software used for gamma analysis. Analytical laboratory will need to: - analyze complex isotope mixture, properly identify isotopes using key gamma lines and correctly apply interferences, - properly apply coincidence summing corrections, - decay results for the reference date, - properly recognize and calculate parent/progeny pairs like Zr-95/Nb-95, I-132/Te-132, Mo-99/Tc-99 etc., - identify additional radionuclides. - FM can be used to identify non gamma emitting radionuclides like Sr-89, Sr-90, Pu-239 etc. based on fission yields, nuclear reactions and irradiation conditions. Fission mixture samples can be delivered as liquid samples and other configurations like filters and cartridges.
Speaker: Dr Evgeny Taskaev (Eckert &amp; Ziegler Analytics, Inc.)
• 60
Quality control for routine k0-NAA applications at Nuclear Physics Institute, Řež
Implementation of the k0-NAA in Řež aimed at the development of routine panoramic trace-element analysis method for samples with various matrices and of different origin. To meet the customers’ expectations, procedures and practices have been established to ensure the high quality of the results produced, such as, calibration of the equipment used (scales, pipettes, detectors), in-situ determination of neutron flux parameters in irradiation channels of the multipurpose research LVR-15 reactor, use of replicates (if possible), blank analyses, use of certified reference materials, namely NIST SRMs 1547, 1633B, 2711, and/or others in case of availability, preferably with a good matrix-match to the samples to be analyzed. Using results of the SRMSs, control charts are maintained to monitor the long-term stability and quality of the assays. For most elements, agreement is obtained with the certified values within uncertainty margins. A procedure has also been designed to use noncertified values for quality control in the same way as the certified values. In a few cases, however, results deviating from the certified or noncertified values are consistently being found, although the differences are not of a systematic nature. Such cases are topics of our future studies. To test and improve the quality control measures, our lab also successfully participated in several inter-laboratory comparison rounds organized and sponsored by the IAEA using test samples of plant and soil origin provided by the Wageningen Evaluating Programs for Analytical Laboratories (WEPAL).
Speaker: Dr Marie Kubešová (Nuclear Physics Institute, ASCR)
• 61
Rapid Analysis of Uranium Concentrations in Powder Rock Samples by a Delayed Neutron Counting
A delayed neutron counting system installed at the HANARO research reactor in the Korea Atomic Energy Research Institute was applied to the analysis of elemental uranium concentrations in the rock samples collected at the Samcheok area, northeastern Yeongnam massif, South Korea. For the accurate determination of uranium, the correction of thorium interference was carried out. The resultant values are consistent with the values determined by the ICP-MS. The DNC method was proven to be a very rapid and excellent method for the quantification of the uranium concentration in the geological samples. Keywords: Delayed neutron counting, uranium concentration, thorium concentration, rock samples
Speaker: Dr Gwang-Min SUN (KAERI)
• 62
Rapid separation and determination of 107Pd and 79Se from intermediate level radioactive waste from NPP A1
Speaker: Mr Boris Andris (VUJE a.s.)
• 63
Selenium in bread and durum wheats grown under a soil-supplementation regime in actual field conditions, determined by cyclic and radiochemical neutron activation analysis
Speaker: Ms Catarina Galinha (CERENA-IST, University of Lisbon)
• 64
Sequential determination of 90Sr, 239Pu and 241Am in urine
Speaker: Mr Ján Bilohuščin (Department of Nuclear Chemistry,Faculty of Natural Sciences, Comenius University in Bratislava, Slovakia 842 15)
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• 65
A rapid separation method for Pu and Sr-90 in seawater samples for emergency preparedness
Artificial radionuclides are released into the environment as a result of nuclear facility accidents and nuclear weapon testing. Among them, strontium, plutonium and cesium are the most frequently monitored in environmental studies. After Fukushima accident, changes of Cs-134/137 concentrations in seawater adjacent to Fukushima are well documented. However, radiostrontium or plutonium concentrations are poorly reported. It is reason that the chemical separation is necessary to determine strontium and plutonium, being beta/alpha emitters, while preconcentration of seawater for gamma emitters is relatively easy. Sequential separation method of Sr and Pu in seawater is studied to prepare for emergency. In general, 50~100L of seawater was needed to determine environmental level of strontium or plutonium in seawater. Casauberta (2013) reported that Sr-90 concentrations were increased by 80 times rather than background levels in Pacific oceans (1.2 Bq/m3) after the accident. At the emergency, 10L of seawater is enough to estimate the impact of the accident. We developed the rapid separation method of Sr and Pu in 1L of seawater and applied it for 10L of seawater. Co-precipitation and extraction chromatography (TEVA, Sr-resin) were used for preconcentration and chemical purification of target radionuclides. And precipitates were dissolved in 8M HNO3, and passed through TEVA resin and Sr-resin, in order. TEVA resin does not hold Sr in the 8M HNO3 medium, while Pu shows maximum uptake. A modular automated radionuclide separator (MARS) developed by our laboratory was applied for purification of Pu and Sr-90. Automated approaches show high potential applicability in emergency preparedness in terms of reducing labor, costs, worker exposure and high throughput. For 1L of seawater, yield of Sr and Pu is 90% and 82%, respectively and finished within 3hrs. The separation of Pu and Sr-90 in 10L of seawater was finished within 10 hrs and yield of Sr and Pu was 60% and 55.2%, respectively. References: Casacuberta et al. 90Sr and 89Sr in seawater off Japan as a consequence of the Fukushima Dai-ichi nuclear accident, Biogeoscinece, 2013, 10, 3649-3659.
Speakers: Dr Geun Ho Chung (Korea Atomic Enegery Research Institute), Dr Hyuncheol Kim (Korea Atomic Enegery Research Institute)
• 66
A Study on Arsenic Speciation in Korean marine samples using Ion Chromatography-Inductively Coupled Plasma Mass Spectrometry
As the toxicity of certain element depends very heavily on their physico-chemical form, it is important to be able to monitor levels of the individual species. Arsenic occurs everywhere in the environment in various forms, including trivalent and pentavalent states, inorganic and organic compounds. In general, pentavalent arsenic is considerably less toxic than trivalent arsenic; inorganic arsenic is more toxic than methylated and other organo-arsenicals. Arsenic speciation in food and dietary supplements is essential in order to provide a meaningful assessment of exposure due to differences in toxicities of the chemical forms. In this study, ion chromatography has been coupled with mass spectrometry to quantitatively determine arsenic species in Korean marine samples We made use of Inductively Coupled Plasma-Mass spectrometry as a sensitive elemental detector in combination with a selective separation technique such as ion chromatography provides information on the chemical form of arsenic compound in some samples. The standard seven arsenic species of Arsenite (As3+), Arsenate(As5+), AsC (arsenocholine), DMA (dimethylarsinic acid), MMA (methylarsonic acid), AsB (arsenobetaine) and TMAO (trimethylarsine oxide) were separated with chromatographic methods, then the arsenic species were selectively detected by ICP-MS. Various extraction procedures were also investigated using reference materials to evaluate the extraction efficiency of the different arsenic species in Korean marine samples
Speaker: Dr Lee Joung Hae (Korea Research Institute of Standards and Science)
• 67
A use of iron(III) hydroxo complexes for removal of radionuclides from solution in the presence of complexing anions
Speaker: Ms Valiantsina Torapava (Joint Institute for Power and Nuclear Research - Sosny, National Academy of Science of Belarus)
• 68
Addition of aluminum salts to water for reducing Co-60 in activated corrosion product deposits on primary system surfaces of nuclear reactor plants.
Radiation situation in occupied areas of nuclear reactor plants is much determined by the activity of loose corrosion product deposits (crud) in the primary system. Co-60 present in crud is the major contributor to personnel exposure because it has a long half-life period and emits hard γ-radiation. Experimental studies have been performed to analyze the possibility of reducing Co-60 in crud on the primary system surfaces. Mechanisms of hydrolysis polymer product formation in mixed nitrate solutions of Fe(III) + Al(III) + Co(II) have been investigated. This hydrolysis process models hydrolysis of corrosion products in the primary coolant water where aluminum salts are added. Analyses have been carried out with gel permeation chromatography and radioisotope and elemental analysis methods. The analysis results show that almost all Co(II) ions which entered hydrolysis polymer products during their initial formation are substituted by aluminum ions as the polymer products age. Since these polymers are precursors to occurrence of loose corrosion product deposits on the primary system surfaces and these deposits include Co-60 as the most important source of radiation exposure, the analysis data attributes improved radiation situation in the occupied areas to addition of aluminum salts to the primary coolant water and demonstrates the usefulness of this addition.
Speaker: Mr Timofey Epimakhov (Vitalevich)
• 69
Adsorption of selected fission products on titanate nanotubes
Inorganic ion exchangers are widely used in the treatment of reactor coolant and aqueous nuclear wastes due to their high selectivity, radiation resistance, thermal and chemical stability. Among other inorganic sorbents, hydrous titanium dioxide was proposed as the prospective sorbent for the efficient separation of fission products such as 137Cs and 90Sr. Recently, new forms of nanometer-sized titanate with unique ion exchange properties were obtained. The physicochemical properties of nanostructured titanates are enhanced and the relation between properties and applications is extended. The aim of our work was studies of ion exchange properties of titanate nanotubes in relation to 137Cs and 85Sr. In the present work we synthesized titanate in nanotube form using hydrothermal procedure. Anatase was heated at the temperature of 140 °C in the 10 M NaOH solution for 24 h. The size and shape were characterized by SEM and TEM methods. The specific surface area was measured by BET technique and the pore size distribution by BJH method. The sorption kinetics studies on titanate nanotubes of 137Cs and 85Sr in form of chlorides were measured in 0.1 M NaNO3 solution. Additionally, the effect of sodium and potassium nitrate concentration and pH on 137Cs and 85Sr sorption were examined. The structure of nanotubes was confirmed by XRD, SEM and TEM methods. The particles diameter was greater than 5 nm and length greater than 100 nm. The measured specific surface area was ca. 300 m2∙g-1 and pore size distribution was equal 0.50 m3∙g-1. Due to high porous structure ion exchange kinetics were relatively slow for Cs+ and Sr2+, but 60% of equilibrium was reached within 1 h. The increasing concentration of Na+ favoured 137Cs sorption than 85Sr. As expected, K+ cations influence on sorption was greater. An increase in Kd value with increasing pH was observed for 85Sr, while in the case of 137Cs the highest sorption was reached at pH 7-9, and at pH higher than 9 the Kd decreased. The results suggest possible applications of titanate nanostructures as inorganic sorbents for the efficient separation of fission products from different liquid wastes, however further studies are necessary. The work has been carried out within the strategic research project entitled "Technologies for the development of safe nuclear energy", phase 7, research task nr 4 (SP/J/4/143 321/11).
Speaker: Dr Seweryn Krajewski (Institute of Nuclear Chemistry and Technology, Warsaw, Poland)
• 70
Analysis of the factors that may lead to misinterpretation of U(VI) complexes time-resolved laser-induced fluorescence spectroscopy data
The aqueous chemistry of Uranium(VI) determines its migration in geosphere under oxic conditions and the efficiency of some technological processes like in situ leach uranium mining, thus being extensively studied in geochemistry. Time-resolved laser-induced fluorescence spectroscopy (TRLIFS) is a powerful method that allows one to determine U(VI) speciation both in aqueous solutions and at mineral-water interfaces. TRLIFS makes use of the sensitivity of U(VI) complexes photophysical parameters (excited state lifetimes and positions of maxima in fluorescence emission spectra) sensitivity to its coordination. Because of high sensitivity and selectivity, this method is extensively used in investigation of various systems containing U(VI), including equilibrium constants determination and monitoring U(VI) speciation in drainage waters. At the same time, the values of excited state lifetimes of, e.g. uranyl fluoride and sulfate complexes, obtained by different groups differ significantly. Moreover, even the question about the number of components required for fluorescence decay curves fitting is not clear: some researchers consider discreet lifetimes for different complexes, while others postulate a continuous dependency of lifetime on ligand concentration and interpret their data under the assumption of fast ligand exchange. Here, we’ll present the extensive study of the reasons that may lead to the discrepancy of photophysical parameters obtained for the same complexes. First, recently, we have demonstrated that the effect of excited states annihilation may influence the shape of fluorescence decay curves at high excitation intensities, thus leading misinterpretation of fluorescence decay rates. Second, different algorithms of fluorescence decay curves processing (the use of fixed lifetimes, global analysis etc.) may provide different values of complexes amplitudes and, consequently, equilibrium constants. Third, we’ll demonstrate the influence of ionic strength of the solution on U(VI) complexes photophysical parameters and stoichiometry by the example of uranyl sulfate complexes.
Speakers: Dr Evgeny Shirshin (M.V. Lomonosov Moscow State University), Dr Vladimir Petrov (M.V. Lomonosov Moscow State University)
• 71
Analytical procedure for the determination of non-gamma-emitting radionuclides in radioactive waste
Speaker: Mrs Veronika Drábová (Department of Nuclear Chemistry,Faculty of Natural Sciences, Comenius University in Bratislava, Slovakia 842 15)
• 72
Automated plant for removing radionuclides from liquid radioactive waste by reverse osmosis
Liquid radioactive waste (LRW) can contain large amounts of emulsified petroleum products and suspended corrosion particles on which radionuclides concentrate. The optimal approach to removal of radionuclides in different physicochemical forms is using adsorption methods together with baromembrane methods such as microfiltration, ultrafiltration, and reverse osmosis. Alexandrov NITI has developed an automated reverse osmosis plant system with remote monitoring and control features including cleaning of reverse osmosis elements. The plant comprises a microfilter, reverse osmosis filter (ROF), unit for cleaning the reverse osmosis elements, low-pressure pump, high-pressure pump, chemical analysis unit, control unit and power control unit. The plant has a filtration capacity of 500 l/h, operating power of 5 kW max, operating pressure of 5 MPa max (at ROF) and removes at least 95% of dissolved salts from LRW with a salt concentration of 10 g/l max and activity up to 10 kBq/l and produces concentrated solutions of up to 50 g/l salt content. The cleaning unit is designed to prepare maximum 150 liters of washing solutions heated to 35оС and clean the reverse osmosis filter. The reverse osmosis elements are cleaned every day using the final water of the plant system and every month using chemical solutions prepared from the final water. The most efficient washing solution is 1.5% solution of citric acid with рН = 4-5. The plant performance is monitored by measuring the solution conductance with the chemical analysis unit and the treatment process is automatically controlled by the control unit equipment. The control and monitoring process does not require presence of the operator in the plant equipment location area. The plant operation is controlled remotely from the operator workstation in another room where the dose rate is below 0.6 μSv/h. Experiments demonstrated that the general demineralization efficiency of the plant was about 75. The system removed almost all petroleum, surfactants, and corrosion products. Alkali metals were removed by ion exchange (pH is reduced). At the same time, the efficiency of radionuclide removal was higher than the general demineralization efficiency. The reverse osmosis efficiency for removal of radionuclides was almost 1000 and even reached the value of 10000 for Sr-90. The chemical cleaning removed fouling consisting of 85% calcium, about 5% magnesium, about 5% iron, and about 1.5 % aluminum species. The specific activity of the washing solutions was 1∙106 Bq/l max with Sr-90 being the main source.
Speaker: Prof. Vitaly Epimakhov (Nikolaevich)
• 73
Characterization of a TBP Resin and development of methods for the separation of actinides and the purification of Sn
TBP is a widely used extractant in liquid–liquid extraction, especially in the extraction of actinides, one of its most prominent examples being the Purex process. A TBP based extraction chromatographic resin has been characterized with respect to its U capacity and the weight distribution ratios (DW) of U, Th, Pu, Np and numerous other cations in different concentrations of HNO3 and HCl. Based on obtained data methods for the separation of Pu from Th and U, and for the purification of Sn, with special focus on decommissioning and radionuclide production, have been developed.
Speaker: Dr Steffen Happel (TrisKem International)
• 74
Combined, sequential procedure for radiochemical analyses of 63Ni, 99Tc, Pu, Th, Am, U and 90Sr in environmental samples
Speaker: Prof. Jerzy-Wojciech Mietelski (The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN))
• 75
Effect of environmental conditions on the sorption behavior of radiocobalt(II) onto permutite studied by batch experiments
Speaker: Mr Xianghai Zhao (School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, P.R.China)
• 76
Effect of mobile phase salinity on the Ac-227/Ra-223 generator.
Radium-223 is the first approved alpha emitting radionuclide for use in radionuclide therapy [1]. Radium follows the Calcium metabolism and thus is self targeted to bones. Several generator systems were described in the past [2]. In this study we have focused on a generator system described by Guseva et al. [3], based on a Dowex-1 resin and a mixed methanol/ nitric acid mobile phase. The effect of NaCl addition into a mobile phase on Ac-227/Th-227/Ra-223 generator was studied. The aim of this study was to increase the efficiency of Ra-223 elution and improvement of the Ra-223 elution peak shape. Possible Th-227 breakthrough was also evaluated. Acknowledgement This work was supported by the Ministry of Education Youth and Sports of the Czech republic, grant No.: LK21310. References 1. Xofigo®, European pharmacopoeia Reg. No.: EU/1/13/873/001 2. McAlister, D. R., Horwitz, E.P.: Chromatographic generator systems for the actinides and natural decay series elements. Radiochimica Acta 99, 151–159 (2011). 3. Guseva, L. I., Tikhomirova, G. S. and Dogadkin N. N.: Anion-Exchange Separation of Radium from Alkaline-Earth Metals and Actinides in Aqueous-Methanol Solutions of HNO3. 227Ac - 223Ra Generator. Radiochemistry 46, 1, 58-62 (2004).
Speakers: Dr Jan Kozempel (FJFI CVUT), Ms Lucie Kománková (FJFI CVUT)
• 77
Effect of Thermal Treatment on Chemical Stability of Resorcinol-Formaldehyde Resins and Their Cs-137 Uptake Properties
Here we present the results of study of interrelations between thermal solidification and selective sorption properties of resorcinol-formaldehyde resins of resol type in highly mineralized alkaline media. Using thermal analysis we have observed a series of exo- and endothermal effects, determined the maximum temperature of thermal treatment, and revealed features of resin solidification in Na- and K-forms. Investigations of Cs-137 sorption under static conditions have shown that resorcinol-formaldehyde resins heated at 100-130°C have low chemical stability in 0.1M NaOH solutions, which has a negative impact on Cs uptake. The increase of temperature during thermal treatment stage results in the increased chemical stability and the selectivity of cesium sorption in highly mineralized alkaline media. We believe that this process is related to the decomposition of methylol groups of resitols under elevated temperature and to the formation of new reaction centers, which finally leads to formation of resitols with highly cross-linked polymer network. Such structure determines high selectivity of the resin to cesium and its stability in alkalines.
Speaker: Dr Dmitry Marinin (Institute of Chemistry FEBRAS, Vladivostok, Russia)
• 78
Extraction and separation of cesium and strontium by crown ethers in organic solvents
Extraction and separation of cesium and strontium is an important issue in radiochemistry, how to solve problems relative to the treatment of liquid radioactive waste (LRW), and for analytical purposes. The best extractants suggested for solving this problem are solutions of crown ethers in organic solvents. This paper presents the results of researches on the extraction of cesium and strontium by various substituted crown ethers from nitric acid solutions, and also from neutral solutions in the presence of activating additives. The following macrocycles: dibenzo-18-crown-6 (DB18C6), dibenzo-21-crown-7 (DB21C7), dibenzo-24-crown-8 (DB24C8), 4,4'(5')-di-tert-butyldibenzo-18-crown-6 (DTBDB18K6), dicyclohexyl-18-crown-6 (DCH18C6) and 4,4 '(5')-di-tert-butyldicyclohexyl-18-crown-6 (DTBDCH18K6) were examined. Polar solvents: 1,2-dichloroethane (DCE), nitrobenzene (NB), chloroform (CL), 1,1,7-trihydrododecafluorheptanol (FH) were selected for researches. The effect of the crown ether structure, the solvent nature and the acid concentration was determined in the extraction of cesium and strontium from nitric acid solution containing 100 mg/L Cs and Sr and 0.1 - 5 mol/L of HNO3 into 0.1 mol/L crown ethers in organic solvents. It has been established that all investigated dibenzocrown ethers considerably extract cesium and don’t extract strontium. At the same time dicyclohexylderivatives are the effective extractants for strontium and don’t extract cesium. The dependence of the distribution coefficients of metals (DCs and DSr) on the concentration of nitric acid has an extreme character with the maximum at 1 - 3 mol/L HNO3 depending on the solvent nature. The difference in the extraction ability of dibenzo- and dicyclohexylderivatives of crown ethers may be used for the separation of radionuclides of cesium and strontium from nitrate media. Also, the processes of extraction of cesium and strontium by 0.01 M solutions of macrocyclic polyethers in organic solvents from neutral nitrate, chloride and sulfate aqueous solutions in the presence of activating additives were studied in this work. Under these conditions, DCs and DSr in the absence of activating additives are close to zero for all examined crown ethers. The introduction of various metal salts as activators into the extraction system doesn’t change this situation. Only in the presence of lithium bis(trifluoromethylsulfonyl)imide (CF3SO2)2NLi both dibenzo and dicyclohexylcrowns extract cesium from the aqueous in to the organic phase with noticeable DCs. Under these conditions strontium is extracted insignificantly only by dicyclohexylderivatives. Our studies have shown that the application of the proposed (CF3SO2)2NLi activator allows to solve the task of the efficient separation of cesium and strontium by extraction with dibenzocrown ethers from neutral solutions. These systems can be used for developing analytical techniques and solving problems in radiochemistry.
Speaker: Ms Nadezhda Tsarenko (JSC «Scientific-research institute of chemical technology»)
• 79
Innovation in metrology: fast automated radiochemical separation for strontium 89 and 90
Speaker: Céline AUGERAY (IRSN)
• 80
Investigation of uranium sorption on materials prepared from tetra-n-butylorthotitanate using LSC and TRLFS
Separation of uranium from natural and waste water is a problem, which has been studied for a long time. For such purpose, many organic and inorganic sorption materials have been proposed and titanium dioxide have shown quite promising results. The first aim of this study was to test and characterize sorption materials based on TiO2 prepared from tetra-n-butylorthotitanate (TBOT) in order to optimize their preparation. The second aim was to implement direct hydrolysis of TBOT in the solutions containing uranium as a method for uranium separation. Sorption capacities of six prepared materials were deduced from their sorption isotherms with fixed uranium concentrations (10 mmol L-1) and variable values of V/m (50 – 400 mL g-1). In the direct hydrolysis experiments, the uranium solutions of 20 and 0.05 mmol L-1 were used. After proper multistage separation, uranium in the samples was measured using liquid scintillation counting and time-resolved laser-induced fluorescence spectrometry which together covered the concentration range of uranium in the samples from tens nmol L-1 to hundredths of mol L-1. For three of the six studied materials, the uranium sorption was studied in more details. In the following experiments, the option of direct hydrolysis of TBOT in the sample was tested. This fast way of uranium separation, which could be suitable for in situ separations, was investigated at various conditions. The results were then compared with the classic sorption method of contacting uranium solutions with pre-prepared, solid absorbers based on TiO2 at similar conditions. It was found that the method of direct hydrolysis in the sample is more efficient separation step than the classic sorption, but it fairly depends on the conditions of the procedure itself.
Speaker: Mr Jakub Raindl (KJCH - FJFI - ČVUT)
• 81
Iodine Adsorption on Modified Nickel Oxide
Speaker: Dr Lórant Szatmáry (ÚJV Řež, a.s.)
• 82
Kinetic and Thermodynamic Modeling Approaches of Selenium by Man-Made and Natural Geological Barriers for Nuclear Waste Management
Some components of nuclear wastes like 79Se should be taken into consideration due to extremely long half-lives and potential migration ability through the environment. Clay minerals are suggested as a barrier material in radioactive waste management; however they have some deficiencies to retard anionic radioisotopes like selenium due to structural properties. Modification of these minerals may help to improve their retardation ability toward these anionic radioisotopes. There are two predominant reasons for limiting selenium in water: a major limiting factor is the possible damage to plants and crops and selenium can represent reproductive dangers for human. The study of sorption kinetics is significant as it provides valuable insights into the reaction pathways and into the mechanism of sorption reactions. The reaction can be defined by a sequence of processes that control the rate, diffusion of ions through particle film, diffusion through the particle and chemical reaction with the functional groups. This paper is dedicated to kinetic performance for selenium removal by selenium selective adsorbent. Batch kinetic experiments were performed using a solution containing 250 mg Se/L (pH 4.0) and 40 mg of inorganic pillared bentonite (OPBent) at three different temperatures and at a certain shaking rate. The selenium concentrations of the samples were monitored by taking the samples from the solution at defined times. The samples were analyzed by high resolution gamma spectroscopy system. The kinetic data obtained were evaluated using classical kinetic models and diffusion/reaction models. The transport mechanism of selenium which comprises a diffusion process from aqueous phase to organo-inorgano-bentonite was described by two kinetic models consisting of derived equations: the homogenous particle diffusion model (HPDM) and the shell progressive model (SPM). The effective particle diffusion coefficient Deff values derived from both the HPMD and SPM equations were compared. The mechanism of selenate sorption by OPBent has been postulated from the experimental results.
Speaker: Ms Ruveyda Kubra Ileri (Istanbul Technical University, Energy Institute)
• 83
Liquid Radioactive Wastes Treatment With Further Immobilization of Radionuclides into Mineral-Similar Sorbents
Speaker: Dr Anna Voronina (Ural Federal University)
• 84
Liquid-liquid extraction of technetium(VII) with TODGA
N,N,N′,N′-tetraoctyl-diglycolamide (TODGA) is broadly studied as a non-specific extractant for actinides and lanthanides from HNO3 solutions of nuclear waste, in particular for group actinide extraction (GANEX process). Unfortunately, some fission products including technetium (in the form of pertechnetate anion, 99TcO4–) are also efficiently extracted from HNO3 solutions to the TODGA-containing organic phase, accompanying the actinides and lanthanides. The present work was focused on modelling the process of technetium extraction to organic solutions of TODGA. The TcO4– anion is evidently extracted to the organic phase as the ion pair, together with a lipophilic cation – the protonated TODGA molecule. We investigated the effects of acidity, of anions that compete with TcO4– for the lipophilic cation, and of diluent on the efficiency of extraction of technetium(VII). The effect of other metals present in the extraction system was also studied. This work was financed from the National Centre for Research and Development through the Strategic Program Technologies Supporting Development of Safe Nuclear Power Engineering, task 4: Development of spent nuclear fuel and radioactive waste management techniques and technologies.
Speaker: Ms Magdalena Rejnis (Institute of Nuclear Chemistry and Technology)
• 85
Long term immobilization of Cs-137 by transformation of titanium ferrocyanide to lithium titanate
Radioactive waste contains a variety of radionuclides and arises in a variety of physical and chemical forms. In Poland, the amount of activity and waste volume of liquid wastes are relatively small, mostly from operation of research reactor. Despite of the low level radioactivity involved, there are many significant hazards that could arise as a result of inadequate management. Treatment of liquid wastes is needed to produce a waste product suitable for long term storage and disposal. Our idea of immobilization of the 137Cs radionuclide in the matrix of TiO2 is based on the initial sorption of 137Cs on titanium ferrocyanide (TCF) and then converting TCF to the TiO2aq by hydroxide solution and calcination of the product to ceramic. We showed that the TCF is a very effective sorbent for 137Cs. In the column experiments we did not observed any breakthrough of the column after passing 10000 bed volumes of the saline solution spiked with 137Cs . After adsorption of the 137Cs on TCF hydroxide solutions were passed through a column and degree of transformation of TCF to TiO2 and leakage from the column was examined. Hydroxides used were as follows : LiOH , NaOH , KOH , and (CH3)4NOH. The obtained results indicate that all hydroxides studied convert, in 100 percent, the black TCF to the white TiO2aq. However, when using NaOH and KOH competing influence of the cations K+ and Na+ causes leakage of 137Cs from formed TiO2 aq. Much better results have been obtained using tetraalkylammonium hydroxide and particularly lithium hydroxide. Competitions from bigger tetraalkylammonium cations and hydrated Li+ on sorption of small hydrated Cs+ cation is negligible. Collected samples of the titanium oxide with adsorbed 137Cs were next calcined at 900oC and the leaching of radionuclides has been studied. Acknowledgments: This work was carried out as part of the Strategic Project ‘‘Safe Nuclear Power Engineering Development Technologies’’ supported by The National Centre for Research and Development, Poland.
Speaker: Prof. Aleksander Bilewicz (Institute of Nuclear Chemistry and Technology)
• 86
Methods for dissolution of [226Ra]BaSO4
Groving interest in the research of radium chemistry, its use as target material in nuclear reaction studies and preparation of calibration sources leads to a higher demand for 226Ra in readily available soluble form. Aged radium needle sources containing very insoluble radiobarite may serve as source material of 226Ra and its decay products (e.g. 210Pb). We descibe here several methods for [226Ra]BaSO4 dissolution including microwave assisted reaction and compare their efficiency in model experiments.
Speaker: Dr Jan Kozempel (FJFI CVUT)
• 87
Nanodiamonds as a prospective sorbent for radionuclides
Detonation nanodiamonds (DND) are potentially promising candidate for sorption applications due to their unique properties: high surface area, highly developed surface, low weight, chemical and radiation resistance. The oxygen-containing groups on the DND surface are responsible for the cation-exchange properties. The sorption capacity of DND is found to be comparable with other carbon nanomaterials as carbon nanotubes and graphene oxide and higher than that of carbon black. The sorption of radionuclides showed to be effected by surface chemistry of DND. It was shown before, that DND can effectively remove U(VI), Am(III), Th(IV), Pu(IV) cations from solutions [1]. In this work the sorption regularities of Th(IV), Ra(II), Ba(II), Ac(III) were studied for different samples of DND: commercially available nanodiamond powder (Sigma-Aldrich) and concentrated suspension, produced at the Special Construction-Technological Bureau "Technolog" of Saint-Petersburg State Institute of Technology (Technical University) (Russia). The radionuclides of interest were chosen with the aim to test nanodiamonds as a prospective sorption material for preparation of 227Ac/223Ra generator. [1] Yu. P. Buchatskaya et al. Proc. of 42èmes Journées des Actinides and 9th School on the Physics and Chemistry of the Actinides, Bristol, England, 2012
Speaker: Ms Yulia Buchatskaya (Czech Technical University in Prague)
• 88
Polyacrylonitrile based composite materials with extraction agents containing chemically bonded CMPO groups for separation of actinoids
Several extraction agents with functional group of diphenyl-carbamoylmethylphosphine oxide were synthetized and tested in the frame of EUROPART project for actinoids partitioning from nitric acid solutions. Functional groups were chemically bonded with a platform of tert-butylcalix[4]arene, O-pentylcalix[4]arene, and cobalt bis(dicarbollide) cluster ion to enhance extraction properties. The extraction agents were used for preparation of composite materials with polyacrylonitrile (PAN) as a binding polymer to study behavior of these composites in column chromatography. They were compared with CMPO-PAN composite material prepared with neat octyl(phenyl)-N,N'-diisobutylcarbamoylmethylphosphine oxide compound (CMPO). Uptake kinetics was studied with europium as an analog of americium. Weight distribution coefficients (Dg) of europium, americium, plutonium, uranium, and neptunium were determined in nitric acid solutions (0.01 - 5 mol/L) in the presence of sodium nitrate (0.1 mol/L). Europium extraction isotherms from 3M HNO3 solution were used for capacity determination.
Speaker: Dr Jan Kameník (Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, 115 19 Prague 1, Czech Republic)
• 89
Preparation and Characterization of Adsorbent Based on Carbon for Pertechnetate Adsorption.
Activated carbon can potentially be used as an adsorbent for removing Tc from aqueous solutions. We have prepared and tested five carbon materials for their capabilities for sorption of pertechnetate (TcO4−). A carbon materials were prepared by soaking of fibrous cellulose with different solutions containing inorganic materials suitable for creation of micropores and after drying, material was carbonized at 500-800 oC. Prepared carbon materials were characterized by BET, acid-base titration, XRD and TEM methods. Sorption of TcO4− on carbon sorbents is fast. For some sorbents even 1 minute is enough to reach more than 99% sorption. Sorption of TcO4− is pH dependant. Maximum Kd was in acidic pH (pH 2-3) and reach about 7x104. Kd were decreasing with increasing pH. In sample B sorption of TcO4− was high even at pH 8 (Kd 5x103).
Speaker: Prof. Pavol Rajec (Faculty of Natural Science, Comeniues University, Bratislava)
• 90
Rapid determination of radiostrontium in milk using automated radionuclides separator and liquid scintillation counter
Speakers: Dr Hyuncheol Kim (Korea Atomic Energy Research Institute, Environmental Radioactivity Assessment Team), Dr Jong Myoung Lim (Korea Atomic Energy Research Institute, Environmental Radioactivity Assessment Team), Dr Kun Ho Chung (Korea Atomic Energy Research Institute, Environmental Radioactivity Assessment Team)
• 91
Speaker: Prof. Vitaly Epimakhov (Nikolaevich)
• 92
Separation and preconcentration of trace amounts of Sr-90 and Tc-99 from primary coolant water using commercially available sorbents and ion-exchangers.
Among the fission products of U-235 are: Sr-90 and Tc-99. Information on their content in primary coolant water is very important because it indicates the state of the fuel rods in NPP. Different analytical methods could be used for the determination of Tc-99 and Sr-90, however each method requires separation and/or preconcentration of determined radionulide. The problems are also related to large volume of samples, what is the case of coolant water. This study outlines some batch and column studies for selective separation of strontium and rhenium (as an analogue of technetium) using commercially available sorbents and ion-exchangers. Preliminary results suggest, that it is possible to separate strontium and technetium from boric acid (main components of primary coolant water and from other beta-emitters. Acknowledgments: Research task No. 8 „Study of processes occurring under regular operation of water circulation systems in nuclear power plants with suggested actions aimed at upgrade of nuclear safety" partly financed by the National Research and Development Centre in the framework of the strategic research project entitled „Technologies Supporting Development of Safe Nuclear Power Engineering”.
Speaker: Mrs Marta Pyszynska (Institute Of Nuclear Chemistry And Technology)
• 93
Separation of Curium from Americium Using Composite Sorbents and Complexing Agent Solutions
Two liquid liquid extraction processes intended as a part of the Partitioning and Transmutation strategy have been used as a basis for development of chromatographic systems for separation of curium from americium. The liquid organic phase of the EXAm process was replaced by DMDOHEMA-PAN composite sorbent and TEDGA in nitric acid solution was employed as an aqueous-phase complexing agent. The liquid organic phase of the AmSel process was replaced by TODGA-PAN composite sorbent and sulfonated BTBP derivative in nitric acid solution was employed as an aqueous-phase complexing agent. The influence of aqueous phase complexing agent and nitric acid concentrations on weight distribution coefficients and separation factor as well as the kinetics of the actinide uptake were determined in batch experiments with trace amounts of Am-241 and Cm-244 radionuclides. The efficiency of Cm separation from Am was evaluated in column experiments.
Speaker: Kamila Šťastná (Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague)
• 94
Solvent extraction of plutonium from environmental samples
The solvent extraction was described for determination of the plutonium presented in the environmental samples. Tri-n-octylphosphine oxide (TOPO) and di-2-ethylhexyl phosphoric acid (HDEHP) were used as the significant reagent of extractants of the plutonium. The extraction properties of TOPO and HDEHP for tetravalent plutonium in 5 mol.L-1 HNO3 into toluene were investigated. The optimal concentration of TOPO for extraction of plutonium was determined (1.10-2 mol.l-1 and higher). These solutions are easily measurable by liquid scintillation method without any further adjustment procedures. The dependences of equilibrium ratios of the plutonium on analytical concentration of chelating agents and pH were studied. The structure of the complex in the organic phase was determined as Pu(NO3)4.2TOPO and the value of extraction constant was calculated. Trivalent lanthanides and actinides, important fission products as cesium, zirconium, strontium and also thorium, uranium with concentration up to 1.10-4 mol l-1 and iron with concentration up to 5.10-3 mol l-1 do not interfere. The goal of this work was to develop selective solvent extraction method for the separation of plutonium.
Speaker: Dr Alena Tokárová (University of defense)
• 95
Sorption of U(VI) by Submicron ZnS Particles from Aqueous Solution.
Uranium is one of the most dangerous radionuclides which makes a major contribution to the total alpha-activity of liquid nuclear wastes. The most promising method for the extraction of radionuclides, including uranium from aqueous media is solid phase extraction. In the last time, different inorganic sorbents (including natural zeolites) having certain advantages over synthetic organic ion exchangers are widely used for the liquid nuclear wastes treatment. Inorganic sorption materials have a high chemical and radiation stability and exhibit high selectivity for certain radionuclides which strongly depends on the pH of aqueous media. Among the inorganic sorbents considerable attention paid to the development of fine sorption materials, which open new possibilities for creating highly efficient process units. A feature of such materials is a large ratio between surface area and volume, which can significantly increase their adsorption capacity. Promising compounds that can be used to produce such materials are fine powders of divalent metal sulfides. It is well known that functional properties of sorbents are largely determined by the size and shape of the particles as well as surface morphology. The goal of this work was to obtain fine powders of ZnS and to study their sorption properties towards U(VI) at different pH of aqueous medium. One of the possible ways of using zinc sulfide particles for analytical purposes is the creation on their basis of sorption-scintillator materials for the determination of low concentrations of alpha radionuclides in natural waters. Sphalerite ZnS with the size of particles of 100-200 nm was obtained using the method of chemical deposition from thiourea solutions. Obtained powders were characterized by XRF, SEM and IR techniques. Sorptive properties of ZnS towards U(VI) at pH 2-9 were studied in batch experiments at 25 ºC using the method of limited volume.The time required to establish sorption equilibrium between the solution and the sorbent was determined from the kinetic curves.It was found that sorption equilibrium in the studied system at pH 7 is established during 60-90 min. The concentration of U(VI) in solutions after sorption was determined by a luminescent method.Luminescence spectra and excitation of uranyl ions were recorded using spectrofluorimeters Avantes(Netherlands). Recovery rate of U(VI) in the range of pH 2-9 was 95-99%. Relative measurement error at a confidence level 0.95 didn't exceed 1%. The observed sorption's features of uranyl ions by fine zinc sulfide enable to assume that for this kind of the sorbent may be different types of sorption processes. Structure sulfide sorbents based primarily on close packing of atoms, which are almost always eliminates the formation of voids in the structure of the appropriate sorbents,than for them are less characteristic sorption acts related to the exchange and non-exchange absorption of ions in the structural voids. High recovery rate of uranyl-ions obtained for ZnS fine powders makes possible their use for water decontamination purposes as well as for analytical concentration followed by determination of uranium radioactivity by alpha spectrometry.
Speaker: Ms Anna Rubailo (Yurievna)
• 96
Study of europium and americium uptake on solid extractant with CMPO and polyacrylonitrile from diluted nitric acid solutions
Octyl(phenyl)-N,N'-diisobutylcarbamoylmethylphosphine oxide (CMPO) extraction agent and polyacrylonitrile (PAN) as binding polymer were used for production of CMPO-PAN solid extractant. The material was previously studied for application in column chromatography for actinoids separation [1]. High uptake of americium and europium on CMPO-PAN solid extractant was observed in diluted nitric acid solutions (0.001-0.1 mol/L) contrary to minimal uptake by CMPO itself. A set of experiments was performed for explanation of this effect that cannot be solely explained by adsorption on PAN support. Materials prepared by modification of the original procedure were tested and compared. Influence of CMPO content in the composite and total nitrate ion concentration in the solution on the uptake were determined for several acidities. Selected materials were subjected to FT-IR analysis to study interaction of the support polymer and CMPO agent. Europium extraction isotherms were measured in the solution of 0.01M HNO3 for capacity determination. It was found that addition of sodium nitrate (0.1 mol/L) increases maximum europium capacity by more than an order of magnitude to the value that was determined in 3M HNO3. The observations indicated that europium and americium uptake mechanism on CMPO-PAN is different in solutions with diluted and more concentrated nitric acid and is influenced by total nitrate concentration. [1] Kameník J., Šebesta F. (2006), Czechoslovak Journal of Physics 56, D493-D500. * Present address: Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Řež, Czech Republic
Speaker: Dr Jan Kameník (Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, 115 19 Prague 1, Czech Republic)
• 97
Study of the DTPA and Malonic Acid solution for the selective Am stripping in the CEA EXAm process
Distler P.*, Spendlikova I.*, Burdet F.+, Miguirditchian M.+ *CTU in Prague, Brehova 7, 115 19 Prague 1, Czech Republic +CEA Marcoule, Nuclear Energy Division, Radiochemistry & Processes Department, SMCS/LEPS, Bagnols-sur-Cèze, F-30207, France In the frame of the development of the French CEA EXAm process (Am selective separation from a PUREX raffinate by solvent extraction), the selective stripping of americium from lanthanides was studied using a solution of DTPA and malonic acid. This step is similar to a reverse-TALSPEAK system developed for Am/Ln separation. Organic phase containing 0.3 M HDEHP and 0.6 M DMDOHEMA in TPH was first loaded with the aqueous phase containing Am/lanthanides/fission and/or corrosive products. The loaded organic phase was then contacted with the aqueous solution of DTPA and malonic acid at pH around 2.5. The impact of DTPA and malonic acid concentrations, pH dependence, kinetic and thermodynamic studies were studied on americium and lanthanides extraction. In addition, the impact of the nature of the base used to pH adjustment and the stability constants of DTPA with Am(III), Eu(III) and Ce(III) were determined in process conditions. These results showed that DTPA and malonic acid extraction system can selectively strip Am(III) over lanthanides (Ce(III) and Eu(III)) and other fission products potentially present in organic phase (Fe(III), Y(III)). The results are important for a better understanding of the process chemistry and are used for the modelling and the simulation of this step of the EXAm process.
Speakers: Mrs Irena Spendlikova (CTU in Prague), Mr Petr Distler (CTU in Prague)
• 98
Technetium and Rhenium sulfide nanodispersion size speciation by SAXS, nanosizer and ultramicrocentrifugation.
K.E. German1,2, A.A. Shiryaev1, A.V. Safonov1,2, Ya. A. Obruchnikova1,2,3, V.A. Ilin1,2, M.N. Glazkova2, V.E. Tregubova1,2, S.N. Kalmykov4, E.V Abkhalimov1 1 – Frumkin Institute of Physical Chemistry and Electrochemistry RAS, Moscow, Russia 2 – Moscow Medical InstituteREAVIZ, Moscow Russia 3 – Mendeleev Russian Chemical Technology University, Moscow, Russia 4 – Lomonosov Moscow State University, Moscow, Russia Technetium and rhenium heptasulfides were among the first synthesized compounds of these elements as considered the convenient route for Tc and Re separation from aqueous solutions. Although in the first works its composition was established as M2S7 (M = Tc, Re) it was rather surprising in view of Tc and Re redox potentials being in contradiction with those of S2-. No reasonable thermodynamic data is available on the solubility of these compounds mostly due to the variety of chemical nature ascribed to these compounds and difficulties in its nano- and micoro- size speciation/attribution. Only the formation kinetics and colloidal particle size speciation studies [1-3] provided with some reliable information on Tc concentration dependences. Structure unit fragment Tc3S13 for technetium sulfide acc. to EXAFS studies [4] contained trinuclear Tc(IV) cluster with 3-S atom inside it and the planar vacancies filled with multiple disulfide ligands, thus explaining the excesses of S in this compound. In the growing process of Tc-S colloid system, the size of colloid particles was shown to increases by deposition of Tc sulfide on the particle surface, not by coagulation of the particles [3]. Recently mixed oxo-sulfide species of Tc were characterized [5]. Here we continue microcentrifuge size speciation in course of the reaction of Tc(VII) and Re(VII) with sulfide and follow it with size speciation of generated particles in the solution by SAXS at specialized small angle diffractometer SAXSess (Anton Paar (Austia), CuK (1.54 А), transmission analises after collimation correction mode, sealed glass capillaries, registration with ImagingPlate). Based on Log(I) = f(s2) plots, s = 4πsin(Θ)/λ) for the aged samples two types of species were observed in Re sulfide colloidal solution by SAXS. Small particles were monodisperse and quite isotropic with Rg = 0.31 – 0.45 nm. Large particles were disc shaped with 40 nm in diameter and 5 nm height. Both methods supported induction period and kinetic dependent on the [Na2S] in the solution and the order of mixing the reagents. Based on the similarity of chemical behavior we suggest similarity in composition of technetium and rhenium species obtaind in the identical conditions. The stability of M3S10 (M = Tc, Re) in the resulting solution was dependent of the S2- concentration in it. When higher than 0.06M Na2S, further grouth of Tc and Re sulfide particles occurred for  ≥ 150 h similar to observations made in [3]. For [Na2S] ≤ 0.04 M, the M3S10 was reoxidized by present air to Tc(VII) within 175-200 hours thus being resolubilized. The determination of the free Tc and Re species concentration with separation of ionic or nanocolloidal particles with 5 kD “Sartorius” ultramicrocentrifuge tubes gave evidence on the M3S10 nanosulfide formation similar to that observed in [4]. The equation for the Tc sulfide solubility based on these figures was evaluated. References 1. El-Waer, S., German, K. E., Peretrukhin, V. F. J. Radioanal. Nucl. Chem., 157 (1992) 3–14. 2. K.E. German, V.F. Peretrukhin, D.N. Tumanova, A.Yu. Tsivadze. Technetium sulfides – role in chemistry and ecology. In: 7th International Symposium on Technetium and Rhenium – Science and Utilization – Book of Proceedings - July 4 -8, 2011, Moscow, Russia (Eds.: K.E. German, B.F. Myasoedov, G.E. Kodina, A.Ya. Maruk, I. D. Troshkina). Publishing House GRANITZA, Moscow 2011, p. 181-186. 3. Y. Saiki, M. Fukuzaki, T. Sekine et all. J. Radioanal. Nucl. Chem. 255 (2003) 101–104. 4. W. W. Lukens, J. J. Bucher, D. K. Shuh, N. M. Edelstein
Speakers: Mr Alexey Safonov (Frumkin"s Institute of Physical Chemistry Russian Academy of Science), Dr Konstantin German (Frumkin"s Institute of Physical Chemistry Russian Academy of Science)
• 99
The Formation of Structure in the Extraction at Vibration in an Interfacial Layer
Formation of cruds at the extraction of metals is the negative phenomenon as reduces the rate of extraction, worsens disintegration of the emulsions, and leads to loss extragent and an extractive element. In practice to prevent the formation of structure in an interfacial layer in system aliphatic alcohols add to aliphatic alcohols, for example, octanol - 1. However there are additional losses extragent, threat of environment increases. The results of researches on influence of the mechanical vibrations on an interface on process of the formation of structure in an organic phase at extraction rare-earth elements by solutions di-(2-ethylhexyl)phosphoric acid are considered. Vibration influence on interfacial layers was carried out by means of the vibrator which represented a high-frequency electrodynamic head with rigidly fixed core, by a coming to an end vibrating element in the form of the triangular prism turned to an interface by top. The vibrator connected to the generator of low-frequency signals. The effective viscosity and limiting pressure of shift of organic phase exposed to vibration is constant during first ~15 min. At short time (~5 min), the main contribution in system behavior is provided by spontaneous surface convection. At longer time intervals (50–60 min) when spontaneous surface convection is absent, it is the vibrations that disintegrate the resulting structure. The supply of additional energy into interfacial layers of extraction system changes the hydrodynamic situation not only in interface region but also in the adjacent domains of contacting phases. The relative motion of particles increases when exposed to mechanical action. Since resulting particles have different weight and move with different velocity, their shift leads to is integration of aggregates in temporary structure. Thus, mechanical vibrations disintegrate the structure at the weakest coagulation contacts. However, the viscosity and a limiting pressure of shift of organic phase sharply increases with time. The nascent temporary structure is heterogeneous, therefore the supply of additional energy leads to its disintegration and particles of smaller size prevail in the system. The interaction of reproduced particles results in the formation of a stronger structure. Thus, the local supply of mechanical energy in an interface layer possible to suppress process of the formation of structure during the initial moments of time.
Speaker: Prof. Nikolay Kizim (Fedorovitch)
• 100
The System СА® (analytical Kit “Анфеж®”) for determination of low levels of radiocesium contamination in liquid media.
The recently developed apparatus named System СА® (Kit “Анфеж®”) and the procedure of its effective application for the concentration and determinination of low levels of radiocesium contamination in liquid media is discussed. The liquid media which can be analyzed by the System СА® include sea water, fresh water, drinking water, wine, milk, juice, human urine etc. The apparatus is designated to rapidly estimate radiocesium contamination of individuals by immediate determination of radionuclides in urine samples. Unlike the known analogs, this analytical Kit is cheap and simple in application. The main element of the system is a plastic chromatographic column which contains 10 to 100 g of granulated ferric cyanoferrate. This chemical is absolutely safe and harmless to human health and is widely recommended as an antidote in the case of radiocesium or thallium poisoning. It is shown experimentally that for quantitative determination of background levels of radiocesium in humans, the volume of the sample should be 900 to 1000 ml of urine and the chromatographic pretreatment may take 3 - 5 min. Our research showed that this analytical Kit can be also used for high-speed concentration of radiocesium from large volumes of water solutions (to 1000 l of sea water) during a short period of time (to 30 min). According to the experimental testing, the analytical Kit allows quick transfer of the saturated sorbent from the chromatographic column to a well-type scintillation detector. The shelf life of the Kit is 5 years.
Speaker: Dr Remez Victor (Ecsorb, the Compamy)
• 101
Thermodynamics and separation factor of uranium from lanthanum on gallium-indium eutectic alloy
Actinides recycling by separation and transmutation are considered worldwide as one of the most promising strategies for more efficient use of the nuclear fuel as well as for nuclear waste minimization, thus contributing to make nuclear energy sustainable. With this purpose, two major fuel reprocessing technologies have been explored so far to separate the actinides from the fission products arising from nuclear energy production: hydrometallurgical and pyrometallurgical processes. Fast neutron reactors allow more efficient use of uranium resources. In addition this type of reactors is capable of burning long lived actinides (including those accumulated in thermal reactors spent fuel) thus reducing radioactivity of nuclear wastes. Application of fast reactors results in considerable increase of fuel burn up and, if the reactor is operated as breeder, reproduces fissile materials. At present non-aqueous pyrochemical methods employing molten salts and liquid metals are developed for reprocessing spent nuclear fuels (SNF) of fast reactors. Inorganic melts have very high radiation stability and can be employed for organizing a short closed fuel cycle. Fissile elements and fission products dissolved in a salt melt can be separated employing selective extraction by liquid metals. Detailed information on the properties and behavior of all elements present in SNF in fused salts and liquid metals is required to design a feasible separation process and these include rare earth elements representing an important group of fission products. Behaviour of lanthanum has so far been studied only in binary systems, Nd-Ga and Nd-In and the behaviour of uranium – only in binary systems, U-Ga [4] and U-In. There is no information on thermodynamic properties of lanthanum and on separation factor of uranium from lanthanum on metallic Ga-In alloys. In the present study the base thermodynamic properties of lanthanum and the separation factor of uranium from lanthanum was determined in Ga-In eutectic alloy. For calculation of thermodynamic properties of lanthanum and the separation factor of uranium from lanthanum the galvanic cells (1) and (2) were used: Mo(s) (La}| 3LiCl-2KCl, La(III)|| 3LiCl-2KCl | С(s), Cl2(g) (1) La (alloy) | 3LiCl-2KCl, La(III)|| 3LiCl-2KCl | С(s), Cl2(g) (2) Variation of the apparent standard redox potential of the couple La(III)/La as a function of the temperature is: E*La(III)/La = - (3.731 ± 0.004) + (8.3 ± 0.6)∙10-4T ± 0.003 V (3) Variation of the apparent standard redox potential of the alloy Me(Ga-In) as a function of the temperature were fitted to the following equation using Software Origin Pro version 7.5. E**La(III)/La(Ga-In) = - (2.906 ± 0.003) + (5.72 ± 0.06)∙10-4T ± 0.002 V (4) E**U(III)/U(Ga-In) = - (2.508 ± 0.006) + (3.82 ± 0.11)∙10-4T ± 0.003 V (5) The activity coefficient of the lanthanum in liquid gallium – indium alloy was determined by equation (6): logγLa(Ga-In) = 3F/2.303RT∙(E*La(III)/La – E**La(III)/La(Ga-In)) (6) logγLa(Ga-In) = 3.91 – 12496/T ± 0.08 (7) The expression for calculation of the separation factor (θ) of the metals M1 (uranium) and M2 (lanthanum) on gallium-indium eutectic alloy can be written as: lnƟ = [(n-m)FE + mFE**2 – nFE**1]/RT (8) Using the temperature dependences of the apparent standard potentials of lanthanum (4) and uranium (5) in alloys, the following expression for separation factor of uranium and neodymium was obtained: lnƟ = -6.61 + 13859/T ± 0.02 (9)
Speakers: Prof. Alena Novoselova (Institute of High-Temperature Electrochemistry UD RAS), Prof. Valeri Smolenski (Institute of High-Temperature Electrochemistry UD RAS), Ms Yana Luk’yanova (State Scientific Centre -Research Institute of Atomic Reactors)
• 102
“Separation of Tc radioisotopes from proton irradiated Ru targets by thermochromatography –preliminary results”
Speakers: Mr Bogdan WĄs (The Henryk Niewodniczański Institute of Nuclear Physics Polish Academy of Sciences, Cracow, Poland), Dr Ryszard Misiak (The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Cracow, Poland)
• Concert Marble Hall

### Marble Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Tuesday, May 13
• Chemistry of Actinide and Trans-actinide Elements 2 Red Hall

### Red Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Prof. Andreas Türler (Paul Scherrer Institute and Bern University), Prof. Igor Izosimov (JINR)
• 103
Gas chromatography of element 113
Speaker: Dr Gospodin Bozhikov (Jlint Institute for Nuclear Research)
• 104
Adsorption behavior of super-heavy elements (Z ≥ 112) on metal and inert surfaces
Speaker: Dr Josef Anton (University of Ulm)
• 105
Higher oxides, peroxides, and superoxides of early transuranium elements: a relativistic density functional study
The results of relativistic electronic structure calculations on simple molecules of higher oxides (actinide oxidation state VI through VIII), peroxides, and superoxides of Pu, Am, and Cm are reported. The calculations employed accurate “small-core” two-component pseudopotentials derived from the outer (valence) shell solutions of the atomic Dirac–Fock–Breit equations with the Fermi nuclear model; the optimal description of the valence (rather than semicore) shells appears essential for reproducing the chemical properties. The molecular semicore/valence many-electron problem was solved by the two-component non-collinear relativistic DFT technique with the fully unrestricted optimization of Kohn–Sham one-electron spinors expanded in weakly contracted Gaussian basis sets; the bases were optimized for spin-orbit-coupled calculations. Ground-state equilibrium structures, vibrational frequencies and charge and spin magnetization density distributions were analyzed in order to characterize the different isomers in chemical terms. The stability of higher oxidation states in oxygen compounds rapidly decreases from Pu to Am and further to Cm. All “true” An tetroxides (An = Pu, Am, Cm), were predicted to be thermodynamically unstable in realistic gas-phase conditions with respect to the decay into lower oxides (An2O6 or An2O7) and molecular oxygen as well as to the conversion into dioxosuperoxides [AnO2](O2) which appear to be the most stable An·4O species in all cases. Structural and magnetization-density features of the tetroxides indicate that Pu and Am are octavalent while Cm is only hexavalent. No structural similarities between higher oxides of Pu-Am and Os-Ir was found. A variety of bis-dioxygen species of different nature (An(O2)2, [AnO2](O2)2) is discussed. The stability of some heterooxide molecules (PuAmO6 and especially PuAmO7) with respect to the transformation to the mixture of the corresponding pure oxides is noticed. Implications for the chemistry of the transuranium element – oxygen systems and the identification of volatile An-oxygen compounds are discussed. The work is partially supported by the RFBR (grant # 13-03-01234). Thanks are due to Prof. C. van Wüllen for providing us with his relativistic DFT code. The calculations were performed at MCC NRC “Kurchatov Institute” (http://computing.kiae.ru/).
Speaker: W. H. Eugen Schwarz (Department of Chemistry, Tsinghua University, Beijing / Theoretical Chemistry, University Siegen)
• 106
Complexation And Extraction Studies Of High Valency Actinides By Salicylideneimine-based Ligands
Increased knowledge of actinide coordination chemistry and the development of advanced actinide separation processes are essential to reducing the radiotoxicity of used nuclear fuel. Commercial separation techniques for nuclear fuel (i.e. PUREX) selectively remove U(VI) and Pu(IV) from the other components, while the minor actinides, e.g. Np and Am, are not extracted. However, these four mid-actinides (U, Np, Pu, Am) all have highly accessible oxidation states (+V, +VI) at which they exist as linear dioxo actinyl ions [AnO2]n+. The An=O bonds are incredibly stable, permitting ligand coordination in the equatorial plane of the metal ion center and affording a geometry for unique bonding characteristics. Tetradentate Schiff bases can be prepared with synthetic ease and have been used extensively in the area of metal ion coordination chemistry. These ligands have rather planar structures that chelate around the equatorial plane of actinyl ions through their N(2)O(2) binding site, presenting the possibility that this distinct coordination environment may facilitate the selective solvent extraction or aqueous retention of pentavalent and hexavalent actinides. We have synthesized multiple organic and water soluble Schiff base ligands, of the salen and salophen type, and have conducted complexation and solvent extraction experiments with UO22+ and NpO2+, as representative actinyl ions. Preliminary results indicate that salen-based ligands show promise for extracting uranium from nitrate media, while a water soluble salen and a lipophilic di-t-butyl-salophen are the most promising in providing crystallized structures with UO22+ and NpO2+. Ongoing studies of these ligands in our laboratories will help to further define possible methods for used nuclear fuel separations.
Speaker: Mr Christian Bustillos (University of California Irvine Department of Chemical Engineering)
• 107
On the origin of selectivity of bis-triazinyl bipyridine ligands for complexation of americium(III) over lanthanides. Quantum mechanical analysis of M–N bonds
Selective separation of actinide elements from highly radioactive nuclear waste is the key issue for modern technologies of nuclear waste reprocessing. Partitioning of long-lived minor actinides, in particular americium, followed by their transmutation into short-lived and stable nuclides would lead to a significant reduction of long-term environmental hazard from this radiotoxic waste, and contribute to the development of safe nuclear power. Derivatives of 6,6’-bis([1,2,4]-triazin-3-yl)-2,2’-bipyridine (BTBP), the tetra-N-dentate lipophilic ligands which selectively extract trivalent actinides (An) over lanthanide fission products (Ln) from nitric acid solutions (modeling PUREX raffinate) to organic solvents (SANEX process), have been considered the most promising species for partitioning the minor actinides from high-level nuclear waste. Recent theoretical studies, carried out on two pairs of americium and europium complexes formed by the BTBP ligands, neutral [ML(NO3)3] and cationic [ML2]3+ where M = AmIII or EuIII, and L = 6,6’-bis-(5,6-diethyl-1,2,4-triazin-3-yl)-2,2’-bipyridine (C2-BTBP) [J. Narbutt, W.P. Oziminski, Dalton Trans. 41, 14416 (2012)], have shown that greater thermodynamic stability (in water) of the Am-L complexes than that of the analogous Eu species, caused by greater covalencies of the Am–N than Eu–N bonds, is the main reason of BTBP selectivity in the separation of these metal ions. Theoretical analysis of Am–N and Eu–N bonds in the BTBP complexes was carried out in this work, with the use of one-component Zeroth Order Regular Approximation (ZORA) Hamiltonian and Kohn-Sham density functional theory. Kohn-Sham orbitals were analyzed with Natural Population Analysis (NPA), Mulliken Population Analysis, Second Order Perturbation Theory (SOPT) implemented for Natural Bond Orbitals (NBO) and Symetrized Fragments Orbitals (SFO) with overlap populations density-of-states (OPDOS). Electron density was analyzed with The Quantum Theory of Atoms in Molecules (QTAIM). The QTAIM analysis for the bond critical points (BCP) confirms mostly ionic character of M-N bonds with slightly bigger covalent contribution for the Am-N than Eu-N bonds. This is due to a bigger charge transfer from the ligand to the Am than Eu ion, in particular to the 6d(Am) and 5d(Eu) orbitals. The results of the SOPT method show that the greater shift of electron density on the 6d(Am) orbitals is due to the large overlap integrals of 6d(Am) with the ligand donor orbitals, not to the smaller energy gap. This is in line with the calculated greater radial expansion of the 6d(Am) than 5d(Eu). The OPDOS coupled with the SFOs has shown that outermost occupied MOs as well as inner MOs are involved in the M-N interactions. This work was financed from the National Centre for Research and Development through the Strategic Program Technologies Supporting Development of Safe Nuclear Power Engineering, task 4: Development of spent nuclear fuel and radioactive waste management techniques and technologies.
Speaker: Prof. Jerzy Narbutt (Institute of Nuclear Chemistry and Technology)
• Chemistry of Nuclear Fuel Cycle 2 Mirror Hall

### Mirror Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>

(1st ASGARD International Workshop)

Conveners: Dr Katja Schmeide (Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology), Nicholas Evans (Loughborough University)
• 108
Humic colloid-associated migration of trivalent radionuclides in an argillaceous formation
Speaker: Dr Christophe Bruggeman (Belgian Nuclear Research Centre SCK•CEN)
• 109
Cesium uptake by Ca/Mg bentonite: evaluation of sorpion experiments by a multicomponent two-site ion-exchange model
Understanding the migration processes in the near-field of the geological disposal of nuclear wastes at the basic level can help to develop models, which may be used in transport codes that can predict the migration of radioactive contaminants in the field scale. Cesium is well adsorbed by clay minerals and many studies concerning adsorption of cesium on different types of clay minerals have been published so far. As in the Czech project of deep underground repository the application of local bentonite is proposed, in this work, cesium adsorption on Czech Ca/Mg bentonite (Rokle deposit, NW Bohemia) has been studied. In our previous study two main differences between Rokle bentonite and worldwide studied Na-bentonites were observed: (1) the great influence of phase ratio m/V on the shape of Cs sorption isotherm in the range of higher Cs concentration, and (2) a substantial content of micas and mica-type clay minerals (about 19 wt. %) that are believed to cause the specific Cs sorption in the lower concentration range due to the presence of the Frayed Edge Sites (FES). In this work, cesium sorption on Ca/Mg-bentonite of the Czech origin was studied using batch technique for wide ranges of both bentonite-to-water ratio (m/V) and initial concentration of CsCl (10(-7) – 0.1 mol/l), isotope Cs-137 was used as a tracer. The total cation-exchange capacity of the bentonite was 0.50 equiv/kg. The experiments revealed non-linear character of cesium sorption, substantially influenced by the m/V. The numerical evaluation of batch experiments performed with the use of PHREEQC, in which exchange reactions between added Cs+ and Mg2+, Ca2+, Na+ and K+ ions sorbed initially on the bentonite were taken into account, enabled to determine selectivity coefficients of all mentioned cations, according to the Gaines-Thomas convention. The model describing exchange reactions mentioned was successfully verified on a broader set of experimental data that was previously interpreted by a simple ion-exchange model taking into account the exchange of cesium with an unspecified divalent cation. The shape of equilibrium isotherms indicated for initial concentrations of cesium smaller than 0.001 mol/l the possibility to describe the cesium uptake on Ca/Mg-bentonite by a two site model. Using this assumption, capacity of the second type of sites with higher selectivity to cesium, was calculated as about 0.01 equiv/kg. This specific cesium sorption capacity, which is generally believed to be associated with the frayed edge sites (FES) of illitic materials, was also measured using AgTU method. The values resulting from both the methods were of the same order, differences were discussed. The first results of 1D transport modelling in the PHREEQC environment respecting the developed multicomponent ion-exchange model could help by the interpretation of results of diffusion transport of some cations in the layer of compacted bentonite.
Speaker: Dr Dušan Vopálka (Department of Nuclear Chemistry, Czech Technical University in Prague, Czech Republic)
• 110
Speciation of technetium after sorption and diffusion in Opalinus Clay
The long-lived radioactive isotope technetium-99 (99Tc, t1/2= 2.14•105 a) is a fission product of 235U and 239Pu and can be released to the environment from nuclear facilities, high-level radioactive waste repositories or as a result from nuclear weapon testing. Its geochemistry is dominated by the very mobile and soluble pertechnetate anion (TcO4-) under oxic, and a less mobile and less soluble TcO2•nH2O phase under anoxic conditions [1]. For the storage of high-level nuclear waste, argillaceous rocks are under investigation as potential host rocks for repositories in several European countries. Thus, detailed information about the interaction of Tc with these host rock formations is mandatory for the assessment of the long-term safety of high-level nuclear waste repositories. For our studies we selected Opalinus Clay (OPA) from Mont Terri, Switzerland, and its corresponding pore water. OPA is mainly composed of clay minerals (66 wt.%), quartz (14 wt.%), calcite (13 wt.%), siderite (3.0 wt.%), pyrite (1.1 wt.%), and organic carbon (0.8 wt.%) [2]. The sorption of 4-13 µM Tc(VII) on OPA powder was studied in batch experiments under aerobic and anaerobic conditions as a function of pH, clay concentration, and amount of dissolved Fe(II). Diffusion experiments were performed with intact OPA bore cores (20x10 mm and 25x11 mm) with diffusion parallel and perpendicular to the bedding. The experiments were performed under aerobic conditions with 7 µM TcO4- at neutral pH. Furthermore, different sorption samples on OPA thin sections (contact area 16 mm²) with 3-35 µM Tc(VII) were prepared under anaerobic conditions for spatially resolved, molecular-level investigations to determine the speciation of Tc on the mineral surface. The batch experiments showed that in the neutral pH range the sorption of Tc on OPA is very low, i.e. ≤ 1% under aerobic and 8% under anaerobic conditions. We also found that the sorption is independent of the clay concentration. Addition of dissolved Fe2+ increased the uptake of Tc by OPA up to 99%. The low sorption of Tc on OPA under aerobic conditions agrees well with our results from diffusion experiments, where Tc(VII) migrates quickly through an intact OPA bore core within about one week in case of diffusion parallel to the bedding. For diffusion perpendicular to the bedding, TcO4- migrates through the bore core within one month. µ-XRF mappings of the sorption samples showed a homogeneous distribution of Tc on the OPA surface with some local enrichments. In these spots the dominant oxidation state of Tc was found to be tetravalent as determined by Tc K-edge µ-XANES measurements. Our results indicate that OPA is able to reduce at least part of TcO4- to a less mobile and less soluble Tc(IV) species and thus may retard the migration of Tc from the repository to the environment. This work was financed by BMWi under contract no. 02E10981. The authors thank Diamond Light Source for access to beamline I18 (Proposal 8725) that contributed to the results presented here and Prof. Mosselmans for his support during the experiment. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement nº 226716. References: [1] K. Lieser; Ch. Bauscher, Radiochim. Acta, 42, 1987,205 [2] NAGRA, Techn. Bericht NTB 02-03, NAGRA Wettingen/Schweiz, 2002
Speaker: Ms Maria Lübke (Institute of Nuclear Chemistry; Johannes Gutenberg University Mainz (Germany))
• 111
Ruprechtov natural analogue site: summary of the real system behaviour
Deep geological repositories (DGR) for the final disposal of spent nuclear fuel and high-level radioactive waste are primarily based on a multi-barrier concepts, consisting of a host rock as a natural geological barrier and an engineered barrier-system. Detailed investigations of suitable geological analogues may lead to a better understanding of the complex interrelations between transport and sorption of radionuclides in multi-barrier systems under natural conditions and especially on very long-term scales relevant for performance assessment. The Ruprechtov site (W Bohemia) was chosen as a natural analogue because the geological and geochemical conditions are similar to sedimentary sequences which in many cases cover the potential host rocks for DGR. The site selection supported also natural accumulations of U, which enabled to identify the main mobilisation/immobilisation processes. During the international research, which took place at Ruprechtov site since 1995, multidisciplinary investigations were performed, including detailed hydrogeological, geological, mineralogical and geochemical characterisation. Furthermore, the core part of the investigations were focused on natural U occurrences as analogue for U migration and immobilisation in the DGR post-operational phase. The Ruprechtov site represents a Tertiary basin with argillized volcano-detritic sediments, underlain by kaolin and granite. U-enrichments mainly occur in distinct layers of limited thickness on top of the kaolin close to the clay-lignite seams (Noseck et al., 2004). The combination of different analytical methods was applied to gain an insight into the behaviour of U in a complex natural system such as wet chemistry (distribution of U(IV) and U(VI), sequential extraction, 234U/238U-activity ratios determination) and various spectroscopic methods (SEM–EDX spectroscopy, synchrotron-based l-EXAFS, EMPA and confocal l-XRF). Noseck et al. (2008) presented the scenario for U enrichment: Microbial activity in the clay/lignite horizon led to the reduction of dissolved sulphate by sulphate-reducing bacteria, thereby leading to the formation of pyrite nodules. Noseck et al. (2008) also identified using determination of 234U/238U activity ratios that the accumulation process has to be at least older than 1 Ma year. In this period, CO2-rich water likely initiated U release from accessory minerals in the granite by formation of soluble uranyl-carbonate complexes. Uranium was transported into the clay/lignite horizon and accumulated there by reduction of U(VI) to U(IV) by thin As-pyrite layers on pyrite nodules formed by microbial sulphate reduction. Moreover, microbial degradation of organic matter in the clay/lignite horizon probably caused also phosphate release into the groundwater. The increased phosphate concentrations caused the precipitation of U as secondary phosphate minerals (e.g. ningyoite). The key processes involved in U immobilisation in the argillaceous layers have been identified and can be used to reconstruct the geological history at the site. The gained results were summarized in several publications (e.g. Noseck et al., 2008, 2009, 2012). Acknowledgment: This research was financially supported by Ministry of Trade and Industry of the Czech Republic (TIP FR-TI1/362 and Pokrok 1H-PK25), by SÚRAO, by the German Federal Ministry of Economics (BMWi) and by the Euratom FP7, Integrated Project FUNMIG. References: Noseck, U., Brasser, Th., Rajlich, P., Laciok, A., Hercík, M.: Radiochim. Acta. 2004; 92, 797–803. Noseck, U., Brasser, Th., Suksi, J., Havlová, V., Hercík, M., Denecke, M. A., Förster, H. J.: J. Phys. Chem. Earth. 2008; 33, 14-16, 969-977. Noseck, U., Rozanski, K., Dulinski, M., Havlová, V., Šráček, O., Brasser, Th., Hercík, M., Buckau, G.: Appl. Geochem. 2009; 24, 9, 1765-1776. Noseck, U., Tullborg, E-L., Suksi, J., Laaksohardu, M., Havlová, V., Denecke, M. A., Buckau, G.: Appl. Geochem. 2012; 27, 490-500.
Speaker: Radek Červinka (ÚJV Řež, a. s., Czech Republic)
• 10:00 AM
Coffee Break Marble Hall

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• Radionuclides in the Environment, Radioecology 1 Mirror Hall

### Mirror Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>

(session dedicated to the memory of prof. Petr Beneš)

Conveners: Prof. Pavel Povinec (Comenius University), Mrs Věra Bečková (National Radiation Protection Institute)
• 112
Memorial of Prof. Petr Beneš
Speakers: Prof. Amares Chatt (Dalhousie University), Prof. Christian Ekberg (Nuclear Chemistry, Chalmers), Prof. Jan John (CTU in Prague, FNSPE, Department of Nuclear Chemistry), Jan Kučera (CTU FNSPE, centrum pro radiochemii a radia?ní chemii)
• 113
Mobility of radiocaesium in boreal forest ecosystems: Influence of precipitation chemistry
Speaker: Prof. Eiliv Steinnes (Norwegian University of Science and Technology)
• 114
Study of 137Cs, 241Am and Pu isotopes sorption behavior in the environment: Prague – Vilnius collaboration*
Results of long-term collaboration with the Czech Technical University in Prague are reported. Sorption behavior of 137Cs, 241Am and Pu isotopes was studied with the aim of better understanding their migration mechanisms in the Triassic clay selected for engineered barrier of the near surface low and intermediate level radioactive waste repository, as well in soil and bottom sediments from the natural environment. The Baltic Sea bottom sediments and well characterized clay samples with different amounts and compositions of iron oxides as well as synthetic magnetite, goethite and hematite were used in equilibrium and kinetic sorption experiments. Sorption was studied as a function of pH, a composition of solutions, and a contact time. The character of Cs, Pu and Am bonding was analyzed by sequential extraction (SE). Solvent extraction techniques, ultrafiltration and alpha spectrometry as well as ICP-MS were employed to characterize the oxidation states of the formed plutonium species. Two Chernobyl soil cores were also analyzed on the vertical distribution of radionuclides, their bonding to soil components, as well as on Pu oxidation state distribution. Experimental data obtained from the laboratory and field observations were used in modeling. Despite their similar sorption kinetics, Pu(IV), Pu(V) and Am(III) showed different bonding to soil, clay and bottom sediment coatings. Pu was predominantly associated with amorphous Fe-oxides and natural organic matter sites, whereas in the case of Am(III), the exchangeable and carbonate sites played the principal role. It has been shown that Pu(V) sorption mechanism includes a very fast Pu (V) reduction (reaction rate ≤ 2.33•10-3s-1) to Pu (IV) and partly to Pu(III). Following reduction Pu isotopes were bound to various components of bottom sediments via ion exchange and surface complexation reactions and a slow incorporation into the crystalline structure of Fe minerals. Kinetics experiments showed that the sorption of Cs(I), Pu(V), Pu(IV) and Am(III) to bottom sediments from natural seawater was controlled by the inert layer diffusion process. The analyses of data obtained from sorption experiments, field observations and speciation of radionuclides have indicated a slightly higher migration potential for Am both in the Chernobyl soil and the natural clay minerals. The exchangeable and carbonate bound Am(III) should display faster migration rate and greater bioavailability in the environment. *) Dedicated to the memory of Prof. Petr Beneš
Speaker: Dr Galina Lujaniene (SRI CENTER FOR PHYSICAL SCIENCES AND TECHNOLOGY)
• 115
Joint Bratislava-Prague AMS/IBA studies using tandem accelerator
P.P. Povinec1, I. Světlík2, J. John3, M. Ješkovský1, M. Němec3, J. Kučera2 1 Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia 2 Institute of Nuclear Physics, Czech Academy of Sciences, Řež near Prague, Czech Republic 3 Faculty of Nuclear and Physical Engineering, Czech Technical University, Prague, Czech Republic A joint research programme has been established to study anthropogenic radionuclides in the environment using Accelerator Mass Spectrometry (AMS), namely 14C variations in the atmosphere and biosphere, and content of plutonium isotopes in the atmosphere and hydrosphere. Specifically, observations of 14C variations in the atmosphere and biosphere around the Czech and Slovak nuclear power plants wil be presented and discussed in detail. Ion Beam Analysis (IBA) techniques have ben applied for radiation damage studies of construction materials of nuclear reactors, and of electronics components working in high radiation fields, e.g. at nuclear reactors and in space instruments. ___________________________ *) Dedicated to the memory of Prof. Petr Beneš
Speaker: Prof. Pavel Povinec (Comenius University)
• Separation Methods, Speciation 2 Red Hall

### Red Hall

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(session dedicated to the memory of prof. Věra Jedináková-Křížová)

Conveners: Prof. Guozhong Wu (Shanghai Institute of Applied Physics, Chinese Academy of Sciences), Dr Ljudmila Benedik (Jožef Stefan Institute)
• 116
Actinide and Lanthanide Interactions with Engineered Mesoporous Materials
Ordered mesoporous materials are attractive sorbents due to their extremely high surface areas, large pore volumes, open frameworks, and highly-ordered, tunable structures. Ultimately, they could be used for separating actinide and lanthanide ions from assorted solution matrices, as well as from each other. Furthermore, functionalized mesoporous materials may be useful for a variety of nuclear and non-nuclear applications including the sequestration of radionuclides for proper long-term storage, environmental sequestration of heavy metals, and nuclear waste reprocessing. Processing of nuclear waste via liquid-liquid solvent extraction produces large amount of high-level liquid wastes that in turn hamper their permanent disposal. Replacing the organic radionuclide extractant solutions with functionalized mesoporous materials, that have the extraction ligands chemically bound to the mesoporous surface, will result in a significant volume reduction and reusability of the material. We are synthesizing non-functionalized and functionalized mesoporous silica and carbon materials to study their interaction with aqueous solutions of europium, neptunium, and plutonium over a wide pH range. This presentation will give an overview of the current status of this research field. I will discuss the characterization and effectiveness of the functionalization of mesoporous silica and carbon by a variety of analytical techniques (FTIR-ATR; PZC; SEM; 13C ssNMR and 29Si ssNMR; TEM; XRD; XAS), the uptake of radionuclides as a function of pH, and the kinetics and reversibility of these processes. Acknowledgement This research was sponsored in part by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program under Award Number DE-NA0001978.
Speaker: Prof. Heino Nitsche (UC Berkeley and Lawrence Berkeley National Laboratory)
• 117
Investigations of water-soluble salicylaldimine-based ligands for the separation of actinyl and non-actinyl cations
Current systems for the separation of actinide and lanthanide cations often employ organophosphorus reagents in combination or in sequence with anionic extractants under acidic conditions. Organophosphorous reagents do not often display large selectivity between trivalent actinides and lanthanides, as a consequence of the similar chemical properties of these elements and may require addition of soft donor ligands. Several of the actinides have higher oxidations states (e.g., V and VI) available under conditions in which they exist as linear dioxo cations. Under this configuration the actinides behave significantly different from trivalent lanthanides. The stability of these oxidation states can be a challenge for some transuranic actinides under acidic conditions. Studies suggest, however, that these oxidation states may be stabilized by coordination of ligands to the equatorial plane of the actinyl ion. For example, recent studies indicate that Schiff bases have been able to stabilize U(V). In light of these reports we are investigating ligands for the selective complexation of An(V/VI)-cations. Possible improvements in Ln/An separation factors may afford the design of separation systems under conditions not commonly considered for nuclear fuel and waste effluent processing. In this paper we present results for the extraction of lanthanide(III) and actinyl(VI) cations from aqueous buffered solutions containing the water-soluble Schiff base N,N'-bis(5-sulfo-salicylidene)ethylenediamine (H2SalenSO3) by bis(2-ethylhexyl)phosphoric acid (HDEHP) in a suitable solvent. The effects of pH, buffer composition, and aqueous complex formation on the partitioning of metal ions are examined in terms of the ability of the aqueous ligand to retain actinyl ions while extracting non-actinyl ions. Spectroscopic and potentiometric titrations of H2SalenSO3 with UO22+ and NaOH have yielded valuable data, including conditional formation constants and ligand pKa values. Both spectroscopic data and the crystal structure of the complex with UO22+ confirm that it has a 1:1 stoichiometry. Notably, visible spectroscopic measurements of solutions of the ligand with Nd(III) indicate that interactions between H2SalenSO3 and Ln(III) are quite weak. Combined with investigations of the effect of ligand hydrolysis on the formation of metal ion complex(es), the results indicate that optimum conditions for complexation occur at acidities lower than those typically maintained in f-element extraction by HDEHP. Therefore, competitive extraction studies have been carried-out at p[H] values between 5 and 6. Continuous contact experiments for U(VI) extraction by HDEHP in toluene in the presence and absence of H2SalenSO3 demonstrate that the uranyl ion distribution ratios (D) are less than 2 and holdback factors are substantial (D0/D ≈ 100 to 800). Because both distribution ratios and holdback factors for Ln(III) extraction under similar conditions remain in the single digits, it is thought that the extent of aqueous ligand hydrolysis and the low acidity present challenges to maintaining extractable species. Investigations of the factors that lead to poor extraction of Ln(III) ions and the evaluation of similar, but more hydrolytically stable ligands, are ongoing.
Speaker: Dr Cory Hawkins (University of California, Irvine)
• 118
Simultaneous extraction of radionuclides with crown ethers and N,N,N’,N’-tetraalkyl diglycolamides mixtures in fluorinated diluents
Speaker: Ms Lyudmila Tkachenko (Khlopin Radium Institute)
• 119
Recovery of actinides and lanthanides on solid-phase extractants from nitric acid solution
Recovery of trivalent actinide and rare earth elements from complicated nitric acid solutions is important and difficult task of radiochemistry. Sorption materials for radionuclide recovery must possess the high sorption efficiency, selectivity of recovery, chemical stability and good kinetic properties. Solid-phase extractants (SPEs) prepared by impregnation of solid supports with ligands are the most appropriate for this purpose. Compounds for impregnation provide formation of complexes with actinides and lanthanides in nitric acid solution and ensure the possibility of their recovery. New types of solid supports for impregnation – high-porous and fine-dispersive polymers and carbon nanomaterials – are very promising for the SPE preparation. These materials ensure strong retention of impregnated ligands, efficiency and stability of SPEs in solutions with high content of nitric acid as well as good kinetic and other properties. This report is focused on sorption ability and efficiency of application of novel SPEs developed by us for recovery of actinide and lanthanide from nitric acid solution. As solid supports we have used Taunit carbon nanomaterial (NanoTech-Center, Russia) and polystyrene polymers – high crosslinked (Isolute, Sweden) or hyper cross-linked (Macronet, UK). For impregnation the phosphorus and nitrogen containing ligands have been used: diphenyldibutylcarbamoylmethylphosphine oxide, tetraoctyldiglycolamide, tri-n-octylphosphine oxide, di-2-ethylhexylmethylphosphonate; these ligands possess of the high efficiency in nitric acid solution also applied in liquid-liquid extraction processes. Impregnation was carried out by solutions of ligands in organic solvents (dichloroethane) or by ligands in nitric acid solution. Impregnation in nitric acid is more advanced technique because it provides high stability of SPEs and efficiency of their application in solution with high content of nitric acid. Novel SPEs have demonstrated high sorption ability toward actinides and lanthanides (distribution coefficients in 3 mol/L HNO3 are 10^3-10^4 mL/g, good kinetic properties and high efficiency of recovery in batch or column mode. On the base of experimental data we have developed the regimes of sorption preconcentration of actinide and lanthanide elements from 1-3 mL 3 mol/L HNO3 and determined conditions of their elution. The selectivity of actinide and lanthanide recovery is conditioned by properties of impregnated ligand and conditions of experiment. In this report we demonstrate examples of selective recovery of trivalent lanthanides with their separation from uranium and thorium. For this purpose we have used solid-phase extractants obtained by impregnation of various types of ligands. By use of multicomponent model solution, the effect of several elements that can be present in solutions of spent fuel reprocessing in nitric acid was examined. Reference: E.A. Zakharchenko, D.A. Malikov, N.P. Molochnikova, G.V. Myasoedova, and Yu.M. Kulyako. Sorption Recovery of U(VI), Pu(IV), and Am(III) from Nitric Acid Solutions with Solid-Phase Extractants Based on Taunit Carbon Nanotubes and Polystyrene Supports. Radiochemistry, 2014, Vol. 56, No. 1, pp. 27–31 Ascnowlegement: The work was supported by Program no.9 of the Presidium of the Russian Academy of Sciences: Development and Improvement of Methods for Chemical Analysis and Structural Study of Substances and Materials
Speaker: Ms Elena Zakharchenko (V.I.Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, Russia)
• 120
Pyrochemical Extraction Analysis of an Immiscible Molten LiCl-KCl/Cd System
Immiscible liquid contacting is one the most common and important phenomena in the high temperature pyrochemical systems. Among these processes, an extraction system employing molten LiCl-KCl and liquid Cd metal has been proposed for the pyrochemical recovery of actinides in a waste salt treatment step. Understanding the complex interaction of immiscible fluid dynamics with mass transfer is a fundamental importance in a liquid-liquid extraction process. The use of a liquid cadmium electrode, which is the unique features of the process, provides hydro-dynamically a free surface contacting with an immiscible molten-salt electrolyte. This free interface of immiscible liquids gives an interface for mass transfer and is inconstant depending on agitated conditions. A computational method to expect an effective area for the mass transfer in the molten-salt and liquid metal system is particularly interesting and challenging for an agitated operation frequently encountered in the pyrochemical system. Details of the calculation of the velocity fields and free surface profiles which evolve in time are given. Representative simulation results are presented to illustrate the capabilities of this method for the molten LiCl-KCl/Cd system. In addition, this study also presents a new modeling approach for studying an analysis of a counter current multistage extraction in the immiscible molten streams. An operational analysis of a counter current multistage extraction was carried out by the model equations, composed of species material balance and distribution relationships between molten salt and cadmium phase. The solutions were determined by using the matrix-based numerical method and the parametric investigations were simulated for the effect of the operating variables on the decontamination factor. The decontamination performance and species concentration profiles could be obtained by considering the flow ratio of immiscible liquids and oxidant feed throughout the multistage extraction step in a given actinides concentration condition of the waste stream.
Speaker: Dr K.R. Kim (Korea Atomic Energy Research Institute)
• 121
Direct Dissolution and Electrochemical Studies of f-elements in Ionic Liquid
The unique and tunable properties of the second generation moisture-stable ionic liquids (ILs) have generated interest in their applications to the nuclear fuel cycle. Generally, ILs have low vapor pressure, chemical and radiation stability, good conductivity, and importantly, wide electrochemical windows. This beneficial electrochemical property allows for the ability to reach the negative potentials that are required for the reduction of lanthanides and actinides to metal species. Reduction of actinides and lanthanides to the metal has been largely unavailable in aqueous systems without the aid of mercury electrodes. Ionic liquids could therefore be envisioned as a system into which the used fuel once dissolved could be used to recover the uranium and separate other fission products by applying different potentials. However, the solubility of f-elements in ILs has not been extensively explored. Therefore, a more fundamental understanding of f-element chemistry and electrochemistry in ionic liquids is necessary to evaluate the system. Exploring methods to enhance and control f-element solubility in ILs is presented. In addition, investigation of the conditions for electrodeposition of uranium from the IL and analysis of the deposited species were conducted. A direct dissolution method which uses the protic form of the anion common to an ionic liquid can provide a pathway for increased solubility of f-elements in ILs. The inclusion of water also enhances the direct dissolution process within the IL. The direct dissolution of lanthanide carbonates and uranium carbonate has been achieved in the IL trimethyl-n-butylammonium bis(trifluoromethanesulfonyl)imide ([Me3NnBu][TFSI]) using the acid bis(trifluoromethanesulfonyl)amide (HTFSI). In addition to the carbonates, direct dissolution of U3O8 was performed. Analysis included UV-Visible and IR spectroscopy to characterize the soluble species and investigate possible complexation with the TFSI ligand. Cyclic voltammetry has been performed at common working electrodes such as Pt, Au, and glassy carbon (GC) to investigate the pathway from the soluble species to reduction. Potential mediated deposition of species from the [Me3NnBu][TFSI] has been achieved and analysis of the deposits was conducted using scanning electron microscopy (SEM) and energy dispersive x-ray emission spectroscopy (EDX). The results indicate that while deposition from the IL is possible despite residual water, the resulting deposited species tend to be oxides. Further studies on electrochemical parameters and utilizing simple methods to remove water are being investigated in an attempt to promote deposition to the metal from IL solutions.
Speaker: Janelle Droessler (University of Nevada, Las Vegas)
• 12:15 PM
Lunch Marble Hall

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• Chemistry of Actinide and Trans-actinide Elements 3 Mirror Hall

### Mirror Hall

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Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Prof. Jerzy Narbutt (Institute of Nuclear Chemistry and Technology), Dr Ladislav Havela (Charles University)
• 122
Utilization of Technetium and Actinide Compound Synthesis and Coordination Chemistry for the Nuclear Fuel Cycle: Exploring Separations, Fuels, and Waste Forms
Compared to other elements on the periodic table, technetium and the actinides are less explored, especially in areas of compound synthesis and coordination chemistry. The nuclear fuel cycle offers opportunities to investigate fundamental and applied technetium and actinide chemistry in more detail, with fundamental complexation chemistry providing insight into waste forms, fuels, and separations. Examples are given for technetium and actinide solution and solid phases, with the coordination chemistry explored by spectroscopy and diffraction. An overview on technetium waste forms is provided, highlighting the need for fundamental information on this element to improved synthetic routes and understand resulting behavior. The thermal and hydrothemal based synthesis of technetium compounds is described. Spectroscopic and diffraction results are provided. Trends in the products from computation [1] and experiment are discussed, emphasizing the role of technetium-technetium interaction with oxidation state change. For waste forms, low valent or metallic phase formation demonstrates enhanced inter-technetium interactions which grants the resulting compounds resistance to corrosion or limits solubility. Development of advanced fuels can leverage innovative synthetic techniques that are utilized in the laboratory and non-nuclear industry. In particular methods that use novel reactions with common starting materials can be applied to produce fuels with suitable attributes for advanced fuel cycles. An example is provided based on the formation of uranium mononitride from dinitride starting material [2]. Uranium dinitride is air stable and can be produced from oxide starting material. Uranium dinitride pellets can be formed in air and then sintered under inert atmosphere to produce uranium mononitride. The unique method for the nitride synthesis can be coupled with established sintering techniques to produce fuel. These waste form and fuel illustrations exemplify the utility synthesis reactions can play in the future fuel cycles. Solution based separation of trivalent lanthanides from Am and Cm is also provided as an example of the utility of speciation and coordination chemistry in the nuclear fuel cycle. Soft donor ligands such as dithiophosphinic acids and bis-1,2,4-triazinylpyridine/bipyridine (BTP/BTBP) derivatives show significant separation selectivity. Many of these ligands are limited by poor stability, constrained working pH range, solubility in suitable solvents, and competition from counter anions. Various triazinyl and bis-triazinylpridine (H, Methyl, Ethyl, Pyridyl and Phenyl) derivatives have been synthesized and their complexation with Eu3+, Tb3+ and Cm3+ by time resolved laser fluorescence spectroscopy presented. The solvent is found to play a significant role in the complexation behavior and resulting speciation and coordination. In the acetonitrile medium, the complexes contain one ligand molecule per metal ion. Spectroscopic signatures change to ML3 species in methanol medium. For hard acceptors acetonitrile is known to be less solvating as compared to methanol. The Eu3+ ion, being a hard cation, is less solvated by acetonitrile and the nitrate counter anion strongly binds with it and the BTP molecules. When the Eu(III) complex of Py-BTP was prepared in acetonitrile medium, the single crystal XRD result shows that it acts as a tetra-dentate ligand with the stoichiometry Eu(Py-BTP)(NO3)3 resulting in 10 coordinated Eu(III) ion. The overall results show the utility of radioelement speciation, compound synthesis, and coordination chemistry in expanding general chemistry knowledge and the development of applications exploiting radionuclide synthesis, speciation, and coordination chemistry. 1. Weck, P.F., et. al Inorg. Chem. 48(14), 6555-6558 (2009). 2. Yeamans, C.B.,et.al J. Nucl. Mat. 347, 75-78 (2008).
Speaker: Prof. Kenneth Czerwinski (University of Nevada, Las Vegas)
• 123
Solid state diffusion interactions of metallic uranium with technetium
In metallic nuclear fuels, uranium will interact with fission products formed at higher burn-ups. Understanding the binary interactions between components is helpful in building a description of the overall system consisting of fuel and fission products. Many of the fission product metals are easy to obtain and study in reactions with metallic depleted uranium to simulate conditions in an active metallic nuclear fuel. Technetium is a major fission product (~ 6% from 235-U) and very little is known about its interaction with uranium: only one phase has been identified (i.e., U2Tc) and no Tc-U binary phase diagram is reported. In this study, the interaction between metallic uranium and technetium at elevated temperature has been investigated. Discs of uranium and technetium were prepared into a couple and heat treated at 1023 K for 120 h. After treatment, the couple was analyzed by Electron Microscopy and the U2Tc phase was identified. In order to better understand the physico-chemistry of binary alloys of uranium with transition metals, discs consisting of uranium with molybdenum, rhenium and ruthenium were prepared, heat treated at 1023 K and analyzed by Electron Microscopy.
Speaker: Prof. Ken Czerwinski (University of Nevada, Las Vegas, United States)
• 124
Application of Multi-Step Excitation Schemes for Detection of Actinides and Lanthanides in Solutions by Laser Specroscopy
Speaker: Prof. Igor Izosimov (JINR)
• 125
Inverse quenching effect of excited U(VI) ions by Eu(III) ions in aqueous solutions
This talk will focus on energy transfer phenomena between hexavalent uranium (U) ions (U(VI)) and trivalent europium ions (Eu(III)). In the literature on this subject [1-3], the interaction between U(VI) and Eu(III) was explained as intramolecular energy transfer from excited U(VI) to Eu(III), and thus, the strong quenching of the luminescence of excited U(VI) by Eu(III) was observed. Because these earlier works were performed at relatively high U(VI) concentrations on the order of a few tens mM using conventional spectrofluorimetry, the precipitation of U(VI) at high pH values and the inner filter effect may interrupt the measurement of luminescence of U(VI). In this work, the time-resolved laser luminescence spectroscopy was adopted to verify the quenching effect of excited U(VI) by Eu(III) at relatively low U concentrations on the order of a few microM. Two types of uranium materials, dissolved U species in aqueous solutions and adsorbed U species onto a silica surface, were prepared with a solution pH range of 4-7. For both U materials, it is apparent that energy transfer between U(VI) and Eu(III) involves the formation of a hetero-polynuclear complex between the hydrolytic U(VI) and Eu(III) species. The new results observed in this work are as follows: (1) the (UO2)3(OH)5+ hydrolytic compound is the major species taking part in the energy transfer process, (2) the first rising part appeared in the luminescence signal waveform of Eu(III) implies direct evidence of energy transfer process from U(VI) to Eu(III), and (3) the negative quenching effect of U(VI) by Eu(III) ions, which represents the enhancement of luminescence of U(VI) with increasing Eu(III) concentration, was observed in aqueous solutions and the reason can be understood in terms of enhanced absorbance of U(VI) for a hetero-polynuclear complex. A similar negative quenching effect of U(VI) by trivalent terbium ions was observed in acidic solutions [4]. Characteristic features on the luminescence and absorption spectra for this complex will be discussed. [1] J.L. Kropp, J. Chem, Phys. 46 (1967) 843-847. [2] B.D. Joshi, A.G.I. Dalvi, T.R. Bangia, J. Luminescen. 10 (1975) 261-266. [3] S.P. Tanner, A.R. Vargenas, Inorg. Chem. 20 (1981) 4384-4386. [4] T. Yamamura, Z. Fazekas, M. Harada, H. Tomiyasu, Phys. Chem. Chem. Phys. 1 (1999) 3491-3496.
Speaker: Dr Euo Chang Jung (Korea Atomic Energy Reserach Institute)
• 126
Spectrophotometric and TRLFS speciation study of UO2(2+) - ChO4(2-) – H2O (Ch = S, Se) system
This experimental study seeks for stability constants $\beta_m°$, absorption $Z_m(\lambda)$ and fluorescence $Z_m(\lambda)$ spectra (including fluorescence lifetimes $\tau_m$) for the individual species of the general formula $[UO_2(ChO_4)_n]^{2-2n}$ (n $\in$ {0; 1; 2; 3}), specific ion interaction theory parameters $\epsilon(i,j)$ between uran-containing species and the most dominantly present ions ($Na^+, ClO_4^-, ChO_4^{2-}, HChO_4^-$) and their temperature dependence (for which the $\Delta H°$ for all present complex species is derived). Our study was done by preparing of several series of solutions (solutions differing by total sulfate/selenate concentration within the series and by total uranium concentration, pH and ionic strength between different series), measurement of the spectra (UV-VIS abs., TRLFS) and subsequent multilinear analysis (based on Singular Value Decomposition, Parallel Factor Analysis, …). The obtained results are compared with the previously measured data (our TRLFS spectra for uranyl-selenate complex species were, however, in the time of the abstract submission novel) and quantum chemical (ab initio and DFT) study, which part is presented on RadChem 2014 as well.
Speaker: Mr Jakub Visnak (Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague)
• Radiation Chemistry 1 Red Hall

### Red Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Dr Sergey Stepanov (Institute of Theoretical and Experimental Physics), Václav Čuba (CTU in Prague - FNSPE)
• 127
Chemical and heavy ion irradiation induction of HPRT mutations in V79 cells
Induction of mutations has been observed in the HPRT locus of the Chinese hamster cells (line V79) after irradiation with accelerated heavy ions and also after the action of chemical agent. The mutant fractions were measured after exposure to two types of accelerated ions: 18O and 20Ne, under three different irradiation conditions. The linear energy transfer (LET) values ranged from 115 to 153 keV/µm. As a chemical agent, the ethanol was used. The dependence of the mutant fraction on expression time (the incubation period of the cells from termination of the irradiation until reseeding on a selective medium containing 6-thioguanine for the isolation of HPRT mutants) was measured for the doses of 0.5, 1, and 2 Gy; and for 1.65 M (10 vol. %) ethanol. The dependence was non-linear for all irradiation conditions. The mutant fraction increased with expression time, reached a maximum, and fell back to the starting level. It was found that after approximately 40 – 45 days (80 – 90 cell generations), mutant fraction returned to the levels typical for spontaneous mutants. The maximum of the mutant fraction on expression time relation was reached in different expression times under various irradiation conditions. The position of this peak was moving with the LET value of the used radiation. The observations were compared to the mutagenic actions of ethanol, which is a potent scavenger of hydroxyl radicals and it will be used in the upcoming research simultaneously with irradiation to observe its protective (or synergistic) effects.
Speaker: Mr Pavel Bláha (CTU in Prague, JINR)
• 128
Photo- and radiation-induced synthesis of (Ni,Zn)O or mixed NiO-ZnO oxides
Set of mixed oxide samples containing crystalline NiO-ZnO with variable composition was prepared by simple irradiation of aqueous solutions containing nickel and/or zinc nitrate hexahydrate, with subsequent annealing. Effects of various types of radiation were studied - solutions were irradiated either by accelerated electrons or UV light. Due to irradiation, weakly crystalline solid precursor was formed. After annealing at 200-300 °C, nanocrystalline (Ni,Zn)O or a mixture of NiO-ZnO oxides were formed, with different amounts of nickel or zinc, depending on the composition of initial solution. Due to high level of interaction between nickel and zinc compounds achieved, formation of solid solution was frequently observed even in the NiO-ZnO mixture. The size of the crystallites was calculated from XRPD spectra to be in order of tens of nm. Photo- or radiation- induced synthesis yields material with quality nanocrystals and very high specific surface area. This work has been supported by the Ministry of the Interior of the Czech Republic, project No. VG20132015132 and by the Grant Agency of the Czech Technical University in Prague, grant No. SGS14/207/OHK4/3T/14.
Speaker: Ms Lenka Procházková (CTU in Prague, Czech Republic)
• 129
Thermal condition monitoring methods applied to degraded cable insulations and jackets
Speaker: Dr Grazyna Przybytniak (Institute of Nuclear Chemistry and Technology)
• 130
Influence of dose rate irradiation on polymers properties
Influence of dose rate irradiation on elongation at break, strength at break and density was evaluated on insulation of cables NSKFA, NSKA and CXFE-V. It was applied gamma irradiation and reactor ïrradiation. It was performed a experimental comparison among three dosimetry systems (alanine, oxalic acid, PFMCH) for reactor irradiation to evaluate the total dose and parts of neutrons and gamma.
Speaker: Dr Martin Cabalka (ÚJV Řež, a. s.)
• 3:00 PM
Coffee Break Marble Hall

### Marble Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
• Nuclear Analytical Methods 2 Mirror Hall

### Mirror Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Prof. Amares Chatt (Dalhousie University), Dr Zsolt Révay (Technische Universität München - FRM II)
• 131
Unraveling the reaction rate conventions for use in the k0 standardization of NAA
The majority of developers and users of the NAA k0 standardization do not realize that this method was launched [1] in terms of the accurate and generally applicable Stoughton-Halperin convention [2] for the description of the (n,γ) reaction rate. Later on, in the article reporting on the first k0-measurements [3], the more practical Høgdahl convention [4] was introduced instead (as had been done in earlier work on k-factors [5]), which was modified to account for a non-ideal (assumed 1/E1+α) epithermal neutron flux distribution thereby introducing Ryves’ concept of the effective resonance energy [6]. This resulted in a user-friendly protocol, which however ruled out some five (n,γ) reactions with a significant deviation from the ideal 1/v cross section dependence in the thermal neutron energy region. Although in the course of the years it was argued [7] that only a few excluded cases did not justify the changeover from a simple convention like Høgdahl’s to a more sophisticated one, finally the rigorously accurate Westcott convention [8] – with introduction of the α epithermal shape factor - was put forward to incorporate the non-1/v cases in the k0 standardization methodology [9]. Obviously, this turned out to be too complex and impractical for a good deal of the k0-NAA community, notably in the context of the Kayzero software [10] where use is made of an intermediate comparator factor defined in terms of the Høgdahl convention. Therefore, recently the “extended Høgdahl convention” [11] was launched, which takes into account the non-1/v cross section behavior by rather randomly inserting Westcott’s g(Tn) factor in the Høgdahl expression, where Tn is the maxwellian neutron temperature. Although the proof of validity of this extension was based on empirical and hardly on scientific arguments, it can nevertheless be regarded as a valid approach – as shown in the present paper where it is derived from the Stoughton-Halperin convention by introducing a few justifiable approximations. Hence, it can be smoothly implemented in the Kayzero software and in other concentration calculation programs while yielding for the 1/v and non-1/v (n,γ) reactions concentration results which are accurate to acceptable, respectively. This is a promising development in the context of the general applicability of the NAA k0 standardization. [1] A. Simonits et al., JRC 24 (1975) 31. [2] R.W. Stoughton and J. Halperin, Nucl. Sci. Eng. 15 (1963) 314. [3] A. Simonits et al., JRC 60 (1980) 461. [4] O. T. Høgdahl, Rept MMPP-226-1, Dec. 1962. [5] F. De Corte et al., JRC. 3 (1969) 205. [6] T. B. Ryves, Metrologia 5 (1969) 119. [7] F. De Corte et al., JRNC 113 (1987) 145. [8] C.H. Westcott, Rept CRRP-960/AECL, reprint 1962. [9] F. De Corte et al., JRNC 179 (1994) 93. [10] R. Van Sluijs, http://www.kayzero.com/ [11] R. Van Sluijs et al., 6th k0 Users Workshop, Budapest 2013, JRNC in press.
Speaker: Dr Frans De Corte ((ex) Ghent University, Belgium and Research Foundation, Flanders)
• 132
Re-determination of the half-life of 229Th
229Th is an alpha-decay nuclide of the neptunium decay series. Though already extinct in nature, 229Th occurs in high amount in spent fuel as the progeny of the long-lived 237Np. 229Th is one of the most widely used tracers in geology, environmental sciences or nuclear chemistry to determine 230Th and 232Th concentrations by mass spectrometry due to the relatively long half-life and to the fact that it does not occur in nature. 229Th as an isotopic tracer plays a special role in nuclear forensics, where its uncertainty associated with its concentration is one of the most dominant components in the uncertainty budget of radiochronometry of illicit nuclear materials1. As the 229Th standards are certified by activity concentration (e.g. Bq g-1), the accurate knowledge of 229Th half-life value is of utmost importance to convert it to amount content (e.g. mol g-1) needed for mass spectrometry. The first precise half-life measurement of 229Th was accomplished by Hagemann et al.2 and gave a value of 7340 ± 160 years. However, a later measurement by Goldstein et al.3 by isotope dilution mass spectrometry reported an approximately 7% higher half-life of 7880 ± 120 years. Recently, Kikunaga et al.4 measured the 229Th half-life by alpha spectrometry. Their half-life value of 7932 ± 55 years is consistent with the result obtained by Goldstein et al., and the authors suggest that the inaccuracy of the early half-life value is attributed to incomplete separation of 233U from its impurities. The aim of the present study is to re-measure the 229Th half-life using inductively coupled plasma mass spectrometry (ICP-MS) at lowest possible uncertainty. By the measurement of the 229Th amount content in the certified 229Th radioactivity standard (SRM 4328C), the half-life of 229Th can be calculated. The amount content of 229Th was determined by two independent methods, both traceable to SI. In the first method, the 229Th amount content was measured by isotope dilution ICP-MS technique, using a natural thorium certified reference material as a tracer. In the second method, the 229Th amount content was measured against a completely separated highly-enriched uranium solution. In this case, the applied uranium sample was completely purified from its thorium decay products beforehand at a well-known time. Thus the 230Th daughter product of the 234U, which serves actually as the tracer for the 229Th determination, can be very precisely calculated knowing the 234U content and the elapsed time between the uranium separation and 229Th determination1. Our measured 229Th half-life of 7921 years with an expanded uncertainty of 56 years (k =2) is in agreement with the latest values. Uncertainty was calculated according to the GUM (Guide for the Expression of Uncertainty in Measurement). The obtained value can help resolve the problem with 229Th half-life discrepancy, and can result in more precise age dating measurements both for geological and nuclear samples. References 1. Z. Varga, A. Nicholl, M. Wallenius and K. Mayer, Analytica Chimica Acta, 2012, 718, 25-31. 2. F. Hagemann, L. I. Katzin, M. H. Studier, G. T. Seaborg and A. Ghiorso, Physical Review, 1950, 79, 435-443. 3. S. J. Goldstein, M. T. Murrell and R. W. Williams, Physical Review C, 1989, 40, 2793-2795. 4. H. Kikunaga, T. Suzuki, M. Nomura, T. Mitsugashira and A. Shinohara, Physical Review C, 2011, 84.
Speaker: Dr Zsolt Varga (EC JRC Institute for Transuranium Elements)
• 133
Activation analysis in studies of tektites and impact glasses
Impact glasses and tektites are formed during fall of large meteorites on the Earth surface (impact) by melting and ejection of surface materials, mainly unconsolidated sediments and sedimentary rocks. In the Nuclear Physics Institute ASCR, methods of neutron and photon activation analyses have been utilized for detailed geochemical characterization of a collection of various tektites and impact glasses: Central European tektites - moldavites, Australasian tektites, impact glasses from the Zhamanshin crater in Kazakhstan - irghizites, and the Libyan Desert Glass. Geochemical analysis of a large representative set of moldavites indicates that a substantial part of their parent materials must have been, besides the surface molasse sediments, also soil layer and plant biomass which are indicated in modavite composition by enrichment in the plant nutrient/essential elements (K, Ca, Mg) and depletion of nonessential elements (Na, Rb, Sr, Ba), similarly to their redistribution during the transfer from soil to plants. The hypothesis has been supported also by analysis of carbon isotope composition of moldavites which is similar to that characteristic of land vegetation. In irghizites, determined contents of Ni, Cr, Mn, Fe and Co, after subtraction of their background contents from terrestrial source materials, allowed to assign the most probable impactor type as an ordinary L5 or L6 chondrite, and assess a range of the meteoritic fraction in the irghizite parent materials to 4 - 21 wt.%. An explanation has been suggested for lower Ir content in irghizites than matching a chondritic component which is based on significantly lower volatility of Ir compared to other meteoritic constituents as Ni, Cr, Mn, Fe and Co. Unambiguous assigning parent materials and finding a parent crater for the Australasian tektites (AAT) still remains an open issue. After critical evaluation and comparison with literature data, the geochemical data acquired in a representative set of AAT point to a "fingerprint" similarity between AAT and Chinese loess which was discussed in literature as a probable AAT precursor much earlier but later was doubted and abandoned due to generally accepted hypothetical location of the impact to Indochina. The data have been coupled with data available in literature for both AAT and their potential precursors on their isotopic composition (Sr, Nd, Li, B, cosmogenic Be-10). The results, together with considering geographical, ballistic and paleoclimatic aspects, put in serious doubt the location of the AAT parent crater in Indochina and bring extensive evidence for possible location of the crater in the deserts in north-central China which are the source area of the Chinese loess. Elemental composition of he Libyan Desert Glass (LDG) points to quartz sand as a main component of the parent materials, with admixture of elements implying an aluminosilicate component (clay minerals cementing quartz grains). A depletion of volatile elements (alkalis, Zn, As, Br, Sb, etc.) may reflect their evaporation loss during the impact. Higher Zr contents coupled with elevated contents of heavy rare earth elements may reflect melting of refractory zircon. LDG has recently been associated with the Kebira Crater on the Libya-Egypt border. The impact area was flooded with seawater during Cenomanian/Turonian stage and the assumed origin of LDG parent materials - compact sandstone with accessory minerals - in marine environment has been supported also by previous Li isotope investigation. No contamination of LDG by meteoritic material has been evidenced. The studies have been supported by the projects 205/09/0991 and 13-22351S of the Czech Science Foundation.
Speaker: Jiří Mizera (Nuclear Physics Institute, Academy of Sciences of the Czech Republic)
• 134
Neutron Depth Profiling with Multipixel Detectors
Neutron Depth Profiling (NDP) is a specific non-destructive nuclear analytical technique used for determination of depth distributions of some technologically important light elements (e.g., Li and B) in the near surface of solids. The NDP for thick samples (with a thickness > several micrometers) is utilized as a 1D profiling technique that enables to obtain a 1D depth distribution (assuming the uniform lateral distribution). In this case, the measurement is performed with a standard semiconductor detector (or a combination of several detectors arranged in a telescope, etc.) with high energy resolution that, consequently, also allows to obtain high depth resolution (~ 10 nm nominal resolution can be achieved). NDP for thin samples can (advantageously) adapt sophisticated detector systems that enable to detect both reaction products (emitted into opposite directions) simultaneously. Consequently, the sandwich arrangement of the NDP spectrometer (i.e., detector-sample-detector) can dramatically reduce (or even eliminate) the unwanted background and improve the detection sensitivity. Interestingly, as detector systems, placed on both sides of the inspected samples, multipixle detectors (e.g., Timepix, Medipix) can be utilized. Here, the first results of the 3D NDP with multipixle detectors are presented. As samples, thin polymeric foils with B or Li atoms, distributed in the microstructured arrays, were utilized. The obtained data showed that the 3D NDP version proved to be an interesting tool for analysis of the 3D micro-distributions of the NDP-relevant elements in thin samples. This capability might be attractive for electronic industry (where B or Li play an important role) or neutron micro-radiography. Acknowledgment: This study was supported by the Technological Agency of the Czech Republic (TACR) under the project No. TA01010237.
Speaker: Dr Jiří Vacík (Nuclear Physics Institute ASCR)
• 135
Determination of impurities in phosphoric acid by INAA
The increasing demand for phosphate fertilizers accounts for approximately 90 % of global phosphoric acid use. In the manufacture of phosphoric acid, thermal and wet processes are used. The thermal process has been abandoned for the production of phosphate fertilizers, because of the amount of energy which is needed. Decomposition of phosphate minerals with an acid, mostly sulphuric acid, is the only economic way to produce phosphoric acid. Phosphate ores, mostly in the form of apatite, are of two major geological types. The principal deposits are sedimentary rocks found, e.g., in Morocco, China, Algeria, Jordan, USA. Significant igneous deposits are found, e.g., in Russia, South Africa, Brazil. Whatever their origin apatites can be highly substituted and have variable compositions. More than 25 elements are known or proposed to substitute in the apatite structure [1]. The potentially hazardous elements found in phosphate rocks include As, Cd, Cr, Hg, Pb, Se, U, and V. Some cause difficulties in the reaction system, whereas others, soluble in phosphoric acid, may end up in the product acid. Therefore, there is a need for analytical method capable of accurate determination of the above and other elemental impurities in phosphoric acid. Instrumental neutron activation analysis (INAA) is a method of choice due to its multielemental capability and favourably low detection limits for most of the above elements. The problem is, however, that irradiation of liquid acids is prohibited in most nuclear reactors for safety reasons. Therefore, a sample preparation procedure is required that leads to “solidified” phosphoric acid. For this purpose, Silva et al. [2] employed precipitation with calcium hydroxide and evaporation for determination of uranium in phosphoric acid. In this work three other procedures were tested, namely (i) deposition of 100‑μL amounts of phosphoric acid onto disks of chromatographic paper Whatman 1 and sealing in polyethylene (PE) irradiation capsule without drying, (ii) precipitation of Ca3(PO4)2 with CaCO3 in a beaker, (iii) precipitation of (NH4)3PO4 by reaction with ammonia vapours in a dessicator (isothermal distillation of NH4OH [3]) directly in the PE irradiation capsules. The first procedure failed, because of breaking the PE capsules and consequent losses of their content on irradiation. In the second procedure, the activities of 47Ca‑47Sc and 49Ca increased background in the gamma‑ray spectra that impaired detection limits of trace elements, as well as blank values of Sr and several other elements due to impurities added with CaCO3. Thus, the third procedure appeared superior due to its simplicity and contamination-free nature. INAA results obtained with the third procedure are presented for four brands of phosphoric acid differing in purity (pro analysis and technical grades) and concentrations (75 %‑85 %). Acknowledgements This work was carried out within the IAEA Technical Cooperation project MOR 13014- MOR/1/007 and supported by the Czech Science Foundation, grant P108/12/G108. References [1] McClellan, GH (1980) J Geol Soc 137: 675‑681. [2] Silva, NC et al. (2009) J Radioanal Nucl Chem 281: 211‑213. [3] Veillon, C and Reamer, DC (1981) Anal Chem 53: 549‑550.
Speaker: Dr Jan Kameník (Nuclear Physics Institute, Academy of Sciences of the Czech Republic)
• 136
Development of 151Sm analytical method for the purpose of nuclear waste characterization
Speaker: Dr Celine GAUTIER (CEA)
• Radiopharmaceutical Chemistry, Labelled Compounds 1 Red Hall

### Red Hall

#### Casino Conference Centre

Reitenbergerova 4/95, Mari&#225;nsk&#233; L&#225;zn&#283;, Czech Republic <font color=white>
Conveners: Dr Alexander Popkov (Samo University), Dr Ondřej Lebeda (Nuclear Physics Institute, Academy of Sciences of the Czech Republic)
• 137
Pre-clinical evaluation of DOTA-conjugated PSMA-inhibitors and their comparison with standard reference Glu-urea-Lys-(Ahx)-HBED-CC
Speaker: Ms Martina Benešová (DKFZ Heidelberg)
• 138
Modified Inorganic Nanoparticles as a Vehicles for Alpha Emitters in Radionuclide therapy
Speaker: Prof. Aleksander Bilewicz (Institute of Nuclear Chemistry and Technology)
• 139
Determining the retention of recoiling daughter nuclides of 225Ac in polymeric nano-carriers
Alpha radionuclide therapy has a great potential in the fight against cancer as proven by a large number of pre-clinical and clinical studies. In vivo generators capable of delivering a highly efficient cascade of alpha particles are also steadily gaining importance. At the moment 225Ac is the most relevant radionuclide that can serve as an in vivo generator, providing four alpha particles with a total energy of 28 MeV. However, due to the recoil effects the daughter recoil atoms, most of which are alpha emitters as well, receive energies that are much higher (> 100 keV) than the energies of chemical bonds (typically around 2- 8 eV) resulting in decoupling of the radionuclide from common targeting agents such as antibodies. The escaped daughter atoms are free to spread in the body and can cause severe harm to healthy tissue, which is considered to be the major challenge in alpha radionuclide therapy. Here, we demonstrate that polymer vesicles (i.e. polymersomes) can retain recoiling daughter nuclei based on an experimental study examining the retention of 221Fr and 213Bi when encapsulating 225Ac. Furthermore, we examined the retention of 209Pb, the daughter nuclide of 213Po, when enclosing 213Bi in the vesicles. Polymersomes composed of poly(butadiene-b-ethylene oxide) were successfully loaded with 225Ac and 213Bi reaching an efficiency of more than 60 % in both cases with negligible loss. The recoil retention of 221Fr and 213Bi were found to increase with the size of the polymersomes, reaching respectively 69 ± 1.5 % and 53 ± 4 for polymersomes having a diameter of 800 nm. The retention of 209Pb subsequent to a single recoil step (i.e. 213Po decaying to 209Pb) was found to be 59 % ± 17 in the case of polymersomes having the same diameter as reported above. Finally, the polymersomes were found to accumulate around the nucleus in tumor cells (HeLa cell line) which is expected to further reduce the harm caused by recoiling alpha emitters, provided that the nano-carriers have favorable pharmacokinetics.
Speaker: Dr Antonia Denkova (TU Delft)
• 140
In vivo study of 111In-loaded polymersomes
Speaker: Ms Robin de Kruijff (Delft University of Technology)
• 141
Investigation of astatine chemistry in solution
Astatine 211 is considered to be one of the most promising candidates for targeted alpha therapy (TAT)[1,2] and it is the subject of a wide research program in Nantes (France). A carrier molecule should transport At-211 to the cancer cells where alpha-particles emitted by the radionuclide would destroy the target. However binding astatine to cancer selective carrier molecules remains a difficult task. It is recognized that many of the basic chemical studies with astatine (At) have unfortunately been set aside, which currently hinders the development of radiotherapeutic agents [3] At-211 is produced in cyclotrons and all investigations were consequently derived from radiochemical studies at ultra-trace concentrations (typically smaller than 10-10mol.L-1). Therefore no spectroscopic tools can be used to assess At chemistry at the molecular level. These two points clearly limit the investigations of its chemistry, and consequently the development of efficient labelling protocols. Based on these considerations, a research program has started to explore the fundamental properties of At using a multi-disciplinary approach combining radiochemistry, analytical chemistry and molecular modelling competences. The object of this contribution is to present the main advances obtained during the past 10 years as regards especially to the particular metallic character of astatine. Our methodology enabled to define a Pourbaix diagram (Eh/pH diagram) for At in non-complexing acidic aqueous medium. In addition to At- species, the experiments and quantum calculations highlighted the existence of two stable At+ and AtO+ cationic forms of astatine [4, 5]. This truly contrasts with others halogens. Recent results on the chemical reactivity of AtO+ demonstrate the potentiality to form both coordination and covalent bonds with organic and inorganic ligands [6-8]. The peculiarity of the AtO+ behaviour in water solvent will be also discussed [9,10]. REFERENCES [1] D. S. Wilbur, Current Radiopharmaceuticals, 2008, 3, 144-176. [2] G. Vaidyanathan et al., Current Radiopharmaceuticals, 2008, 1, 177-196. [3] D. S. Wilbur, Nature chemistry, 2013, 5, 246. [4] J. Champion et al., The Journal of Physical Chemistry A, 2010, 114, 576-582. [5] A. Sabatié-Gogova et al. Analytical Chimica acta, 2012, 721, 182. [6] J. Champion et al. Inorganica Chimica Acta, 2009, 362, 2654-2661. [7] J. Champion et al. Physical Chemistry Chemical Physics, 2011, 13, 14984-14992. [8] J. Champion et al. The Journal of Physical Chemistry A, 2013, 117, 1983-1990. [9] T. Ayed et al. The Journal of Physical Chemistry B 2013, 117, 5206−5211 [10] T. Ayed et al. The Journal of Physical Chemistry B, 117, 10589−10595
Speaker: Dr David Teze (CNRS)
• Poster Session - Chemistry of Actinide and Trans-actinide Elements
• 142
A Quantum Chemical Study on the Actinides Triflates An(OTf)n where (An= Th, U, Np, Pu, Am, Cm, Bk and No ); n= (3, 4)
The actinides triflates are formed from a central metal that relates to the ligands (CF3SO3-). The transition metal triflates (trifluoromethanesulfonates) are much considered as Lewis acid catalysts in a variety of organic reactions, as well as precursors in inorganic and organometallic synthesis. In coordination chemistry, the selective complexation of actinides (ш) over lanthanides (ш) with efficient extractant molecules is an important problem for both its fundamental aspects and its applications, in particular in the partitioning of spent nuclear fuels. We carry out a quantum calculation based on the density functional theory (DFT) of the actinide triflates complexes. Our aim is to study the structural proprieties changes of these complexes geometries. Furthermore we report the computational study on An(OTf)n where (An= Th, U, Np, Pu, Am, Cm, Bk and No ); n = (3, 4). The quantum calculation DFT proved that the trigonal prismatic geometry is favored for all the studied actinide complexes of the general formula An(OTf)3 where ( An= Th, U, Np, Pu, Am, Cm, Bk and No ) so as by the lanthanide triflate complexes; where the trigonal prismatic geometry is most distorted in the case of triflate thorium Th(OTf)3 and almost perfect in the case of U(OTf)3. The OTf group is bonded to the central metal An as a bidentate ligand with a number of coordination equal to six. For the An(OTF)4 where ( An= Th, U and Pu), the optimized geometry results showed a dodecahedron geometry. Differences in the structural parameters (bond, lengths and angles) can be attributed partly to the nature of the metal atoms and the structural arrangement of the studied compounds. Keywords: actinide- triflate- catalyst- DFT- trigonal prismatic.
Speaker: Prof. nadia ouddai (univ Hadj-Lakhdar batna Algeria)
• 143
Calculation of boiling temperature of seaborgium hexafluoride
The formulation of the Mendeleyev's Periodic law says: "Properties of chemical elements and their connections are in periodic dependence..." Therefore, it is possible to define evaluate unknown or by practical consideration inaccessible constants of some connections operating with various constants of similar substances in chemical behavior [1]. Chemical similar substances are connections with a close factor of intermolecular interaction (ψ-factor). They possess the actual identical chemical properties. For calculation and an assessment of unknown physical and chemical constants, in particular, boiling temperatures widely use methods of comparative calculation if temperatures of boiling of similar connections are known, for example. A boiling temperature is one of the main characteristic constants of any substance. For molecular connections there is the following dependence: (Tb•M) 0, 5 = f (M) (1) them Tb – a boiling temperature, К; M – molecular mass of substance, g-mol. Dependence (1) is a straight line for similar in the chemical relation of hexafluorides of the chrome, the molybdenum and the tungsten, and also uranium. According to works [2-4] character of a chemical bond in CrF6 molecules (ψ = < 0, 05), UF6 (ψ = 0,028), MoF6 (ψ = 0,038) and WF6 (ψ = 0,028) is mainly covalent, i.e. these connections define as molecular. Chemical element No 106 which has the name "seaborgium", is chemical analog of elements of a chrome subgroup. It is possible to tell surely that seaborgium forms molecular hexafluoride, though possessing considerably smaller oxidizing ability in comparison with MoF6 and even with WF6 [4]. Function (1) was applied to calculation of boiling temperature of seaborgium hexafluoride, it was equal 355 K. Literature 1. L. Pauling General Chemistry. Freeman, San Francisco, 1970. 2. K. Ohwada On the ionic and covalent characters of uranium-fluorine bonds in complex fluorides of uranium. // J. Inorg. nucl. Chem., 1976, vol. 38, No 4, pp. 741-745. 3. A.G. Morachevsky, I.B. Sladkov Physical and chemical properties of molecular inorganic connections. – L.: Chemistry. 1987 . p. 59. 4. T.A. O´Donnell, A.B. Waugh and C.H. Randall Reactivity of transition metal fluorides. Part IX. // J. Inorg. nucl. Chem., 1977, vol. 39, No 9, pp. 1597-1600.
Speaker: Dr Oleg Gromov (Borisovich)
• 144
Electrolytic reduction studies of Mo and W towards the reduction of seaborgium
Seaborgium (Sg), element 106, is the third transactinide element placed at the 7th row of the Periodic Table. Similar to its lighter group-6 homologs, Mo and W, Sg is expected to be redox-active in aqueous solutions. Pershina et al. [1] theoretically calculated the redox potentials of various couples of Sg on the basis of its multiple ionization-potentials [2]. They predicted that the redox couples of Sg such as Sg(VI)/Sg(V) and Sg(VI)/Sg(IV) have a more negative redox potentials than those of the corresponding Cr, Mo, and W ones in acidic solutions [1]. This is because the reduction processes of Sg are associated with its lower ionization potentials due to the large destabilization of 6d atomic orbitals [1]. Experimental determinations of redox potentials of Sg, therefore, provide tests of these theoretical predictions and yield information on the stability of the valence 6d orbital. The best Sg isotope for chemical investigation is 265a,bSg (a and b denote the ground and isomeric state) produced in the 248Cm(22Ne, 5n)265a,bSg reaction. Because of low production rates of 265a,bSg and their short half-live of 8.5 s and 14.4 s [3], respectively, only single atoms of Sg are present during an experiment. Standard electrochemical techniques are, thus, not applicable to reduction studies of Sg. Furthermore, continuously rapid experiments are required to efficiently separate reduced and non-reduced species and to measure the alpha decay of 265a,bSg within its lifetimes. We are, therefore, developing a novel chemistry assembly consisting of a membrane degasser, a flow electrolytic column (FEC) [4], and the continuous liquid-liquid extraction apparatus SISAK coupled with a liquid scintillation counting system [5] to carry out a continuous reduction experiment of Sg. The development of suitable liquid-liquid extraction schemes are described in a separate contribution [6]. In this contribution, electrolytic reduction of Mo and W using a FEC to prepare the reduction experiment of Sg is presented. We carried out batch-wise electrolytic reduction of carrier-free 93mMo and 176,181W radiotracers using a FEC. The electrolyzed samples from a FEC were chemically analyzed by solvent extraction with TOA and HDEHP to separate and identify reduced species from the stable Mo(VI) and W(VI) ones based on their different extraction behavior. 93mMo and 176, 181W were applied as radiotracers. We also performed cyclic voltammetry and UV/Vis absorption spectrometry of macro amounts of Mo and W in acidic solutions to obtain information on redox reactions of these elements under given conditions. In this conference, the present status of the preparatory reduction experiments with Mo and W will be presented. [1] V. Pershina et al., J. Phys. Chem. A 103, 8463-8470 (1999). [2] E. Johnson et al., J. Phys. Chem. A 103, 8458-8462 (1999). [3] H. Haba et al., Phys. Rev. C 85, 024611-1-11 (2012). [4] A. Toyoshima et al., Radiochim. Acta 96, 323-326 (2008). [5] J. P. Omtvedt et al., Eur. Phys. J. D 45, 91-97 (2007). [6] M. Attallah et al., contribution to this conference
Speaker: Dr Atsushi Toyoshima (Japan Atomic Energy Agency)
• 145
Gas phase chemistry of the volatile chloride compound of Hf isotopes
Gas-phase chemistry is one of the most utilized techniques to study chemical properties of superheavy elements. An adsorption enthalpy of volatile compounds of these elements can be determined with their adsorption-desorption processes on a gas chromatographic column surface. The gas phase chemistry for group 4 elements, Zr, Hf, and Rf has been performed by several groups, and it is reported that the order of the volatility of their tetrachlorides is Zr≧Rf>Hf [1, 2] and Zr~Hf~Rf [3]. However, in macro-scale, tetrachloride of Hf is known to be more volatile than that of Hf. Until now, we have investigated gas chromatographic behavior of volatile chloride compounds of Zr and Hf, and the transfer process in the column using Hf radioisotopes of various half-lives. The results show a similar behavior with nonvolatile compound, oxychloride which is formed by oxygen in a system [1]. Therefore, we investigated in detail oxygen effects on a gas chromatographic behavior. Hf isotopes were produced in the natEu(19F,xn) and 152Gd(18O,xn) reactions using 20 MV tandem accelerator at Japan Atomic Energy Agency (JAEA). The beam energy of 19F and 18O were 122 and 108 MeV, respectively. Produced Hf isotopes were 165Hf (76 s), 166Hf (6.8 min), 167Hf (2.05 min). To compare volatility with a Zr compound, 85Zr (7.9 min) was also produced in the natGa(19F,xn) and natGe(18O,xn) reaction. Nuclear reaction products were transported to the gas chromatographic apparatus with a carbon cluster in a helium gas flow. The transported products were collected on quartz wool plugged in a quartz tube where HCl gas added to form volatile chloride compounds. Oxygen gas was also introduced in order to examine an oxygen effect on a gas chromatographic behavior. The volatile compounds through the isothermal column were re-transported using a He/KCl gas-jet system, and collected in a cold trap where gamma-rays were measured to obtain the yield of each Hf isotope which passed through the column. The relative yields for 165,166,167Hf and 85Zr are regarded as 100% at the column temperature of 450 C. In the condition of oxygen free, the yields of all nuclides increased with the temperature of the column from 200 C up to 300 C. When oxygen was added into the system, the yields at 300 C were very low and the temperature to which the yield reaches to 100 % was 400 C. Since this result agrees with our previous results, it is found that oxygen had actually influenced the chromatographic behavior reported until now. In the model generally used for analysis of the gas-phase chemistry, it is explained that the yield of the volatile compound changes according to the half-life of the nuclide used. But our experimental results show that nuclides of different half-lives exhibit almost the same breakthrough curves in an isothermal chromatography. The detailed reason is under investigation. [1] A. Tuerler et al., J.Radioanal. Nucl. Chem. 1992, 160, 327-339 [2] B. Kadkhodayan et al., Radiochim. Acta 1996, 72, 169-178. [3] T. K. Sato et al., J. Nucl. and Radiochem. Sci. 2005, 6, N1-N3.
Speaker: Prof. Hisaaki Kudo (Niigata University)
• 146
Measurement of the First Ionization Potentials of Short-lived Lanthanides Using a Surface Ionization Method
The first ionization potential (IP) directly reflects a valence electronic configuration influenced by relativistic effects which are significantly noticeable for heavy elements. Information on IP of heavy elements, therefore, gives us a better understanding of relativistic effects. IPs of heavy actinides with atomic number Z > 100, however, have not been measured by conventional techniques, such as resonance ionization mass spectrometry (RIMS), because these elements are only available in non-weighable quantities down to the one-atom-at-a-time scale. This condition forces us to call for a different experimental approach. Here, we have focused on a surface ionization process. Since the surface ionization process takes place between an atom and a metal surface, this method is applicable to one-atom-at-a-time scale experiments. In fact, we ionized and mass-separated short-lived isotopes using the surface ionization method installed in the JAEA-ISOL system [1]. Further improvement of the surface ionization type ion-source has been recently applied to measure the IP of lawrencium (Lr, Z = 103). 27-s 256Lr produced in the 249Cf + 11B reaction was successfully ionized [2]. The IP measurement of Lr is now under way. In this work, we measured ionization efficiencies of various short-lived lanthanides and evaluated their IPs, as a test experiment for measurement of IPs of heavy actinides. Short-lived lanthanides, 143mSm, 143Eu, 148mTb, 154Ho, 157Er, and 165Yb, were produced by the irradiation of a 67.9- MeV 11B4+ beam delivered from the JAEA tandem accelerator on 136Ce / 141Pr / 159Tb and 142Nd / 147Sm / natEu targets. Short-lived 168Lu was also produced in the reaction of 162Dy with a 11B4+ beam. Nuclear reaction products recoiling from the targets were transported to the ion-source of the JAEA-ISOL set up by a He/CdI2 gas-jet transport system. The products were ionized in the ion-source, accelerated with 30 kV, mass-separated, and collected on an aluminized Mylar tape. The amounts of the collected ions were determined by gamma-ray measurement with a HP-Ge detector. To calculate ionization efficiencies, the amounts of the transported products were also determined by direct collection using a separate catcher system. IPs of various short-lived lanthanides are evaluated based on the following Saha-Langmuir equation: α= n_i/n_0 =exp((φ-IP)/kT) , where n_i and n_0 indicate the number of ions and that of atoms on a metal surface, respectively. T, k, and φ are the absolute temperature of the metal surface, the Boltzmann constant, and the work function of the specific metal surface, respectively. The experimental ionization efficiency β is expressed by using the α as follows: β= n_i/(n_0+n_i )= α/(α+1) . Obtained IP values of short-lived lanthanides with tracer scale atoms were compared with literature values measured with macro-scale amounts of these elements. [1] S. Ichikawa, et al., Nucl. Instr. and Meth. A 374, 330 (1996). [2] T. K. Sato, et al., Rev. Sci. Instrum. 84, 023304 (2013).
Speaker: Mr Yusuke Kaneya (Graduate School of Science and Engineering, Ibaraki University / Japan Atomic Energy Agency)
• 147
Mechanism of addition-fragmentation reaction of thiocarbonyls compounds in free radical polymerization. A DFT study
In the present study we analyze the reaction mechanisms involved by Xanthates (SA(C@S)AO) and Thiocarbonates (OA(C@S)AO) compounds in a reversible addition fragmentation chain transfer (RAFT) polymerization. For the purpose, theoretical calculations have been performed by means of density functional theory (DFT), using the B3LYP, M06, CAM-B3LYP, LC-xPBE exchange correlation functionals and 6-31G⁄ basis sets. Thanks to the transition state theory, the rates of addition and fragmentation reactions were obtained. It is shown that, for these systems, the fragmentation step is more selective than the addition step, and that the range-separated functionals give results close to the experimental trends.
Speaker: Dr nadjia latelli (chemistry)
• 148
Preliminary investigations towards the separation of hexavalent and tetravalent seaborgium - extraction of homologs
Element 106, seaborgium (Sg) is a group-6 element with the lighter homologs tungsten (W) and molybdenum (Mo). The homologs have several stable oxidation states in aqueous solutions. Therefore, one can empirically expect that Sg should exhibit similar properties. In addition, theoretical estimates of redox potentials of group-6 elements show that Sg can be reduced from the most stable hexavalent state to a lower oxidation state [1]. The aim of the present study is to find a suitable chemical extraction and separation system to be applied in future reduction studies of Sg [2] to distinguish and isolate reduced species from Sg(VI) by its different extraction behavior in a subsequent liquid-liquid extraction stage. Our strategy to achieve this is to identify a chemical system where the reduced and non-reduced species in solution have opposite charge. It should then be possible to distinguish between them by simply using a cation or anion extraction agent. Details of the strategy and overall system for performing liquid-phase redox studies on seaborgium will be presented in a separate contribution to this RadChem conference [3]. The extraction behavior of Mo(VI) and W(VI) from HCl with Hinokitol in toluene has been investigated in our previous work [4]. In the present work, we have focused our investigation towards systems where reduced species are anionic and hexavalent ions are cationic. Radiotracers of 89Zr and 93mMo was used to represent reduced species of Sg(IV) and non-oxidized Sg(VI), respectively. 0.1 M solutions of H2SO4, HCl, and HClO4 with and without 0.01 M HF were investigated. Di-(2-ethylhexyl)phosphoric acid (HDEHP) and Tri-n-octylamine (TOA) dissolved in toluene were used as extraction agents. The Oslo Cyclotron Laboratory's (OCL) MC35 Scanditronix Cyclotron was used for producing the 89Zr and 93mMo radiotracer. While all these experiments were performed as discontinuous "batch" extractions, in the future, on-line studies will have to be performed using the full on-line and automated system (SISAK with a redox cell, see [3] for details) to test realistic conditions for a Sg experiment. 30 MeV 4He2+ ions, delivered with an intensity of ~350 nA (electrical), were used for the nuclear reactions natZr(α,x)93mMo and natSr(α,x)89Zr. The activity was then transported in a KCl gas-jet and was deposited on a filter paper. This was gently washed off using the desired aqueous solution. The solution was mixed with an organic extractant dissolved in toluene and was violently shaken for 5 min using a Vortex shaker. Using H2SO4 + 0.01 M HF with either 0.1 M HDEHP or 0.1 M TOA gave the best separation between Mo and Zr. The obtained results indicate that a solution of 0.1 M H2SO4 + 0.01 M HF with 0.1M HDEHP provided the best separation: 88% Mo(VI) and 12% Zr(IV) were extracted. This is a promising start to develop suitable conditions for a future element 106 (Sg) experiment. These experiments will be presented in more detail. Preliminary data of the reduction of Mo(VI) to Mo(IV) using a Flow Electrolytic Column (FEC) [5] in combination with a promising extraction system will be presented by Toyoshima et al. in a parallel contribution to this conference [2]. References [1] V. Pershina, E. Johnson, and B. Fricke. “Theoretical Estimates of Redox Potentials for Group 6 Elements, Including Element 106, Seaborgium, in Acid Solutions”. In: The Journal of Physical Chemistry A 103 (1999), pp. 8463–8470. [2] A. Toyoshima et al., contribution to this conference [3] J.P. Omtvedt et al., contribution to this conference [4] S. Miyashita et al. ‘’Solvent extraction of hexavalent Mo and W using 4-isopropyltropolone (Hinokitol) for seaborgium (Sg) reduction experiment’’ APSORC 13, Kanazawa – Japan. [5] A. Toyoshima et al. “Development of an Electrochemistry Apparatus for the Heaviest Elements”. In: Radiochemica acta 96 (2008), pp. 323–326.
Speakers: Mr H. V. Lerum (Chemistry Department - University of Oslo), Dr Mohamed F. Attallah (Chemistry Department, University of Oslo, Norway)
• 149
Study of Np(V) complexation with propionate and lactate at room temperature
A.N. Vasiliev1,2, N. L. Banik1, R. Marsac1, C. M. Marquardt1, S. N. Kalmykov2 1Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal, 76021 Karlsruhe, Germany 2 Lomonosov Moscow State University, Department of Chemistry, 119991 Moscow, Russia Np-237 is one of the important contributors to the radiation inventory of nuclear waste repositories over a very long time period, because of its long half-life (2.14•106 y). Natural clay rocks are considered as potential host rocks for deep geological disposal of nuclear waste, because of their low permeability and high retention properties for radionuclides via sorption processes. However, small organic molecules, such as lactate and propionate exist in clay rock pore water and they might enhance Np mobility. The understanding of the complexation of Np with these ligands and reliable complex formation data are required in the frame of safety assessment of a nuclear waste repository. Two methods were applied and compared for the determination of Np(V) (NpO2+) complexation with propionate ([Prop] = 0-0.30 mol/L) and lactate ([Lact] = 0-0.33 mol/L), namely UV-Vis/NIR spectroscopy and liquid-liquid extraction (LLE) technique with isoamyl alcohol solution containing 10-3 M TTA and 5•10-4 M 1,10-phenanthroline [1]. All measurements were performed at 0.5 M ionic strength of NaCl solution at room temperature (22±1 °C). The concentration of 237Np(V) in LLE experiments was 1∙10-6 - 3∙10-6 M at pH 7. Liquid scintillation counting was used for the determination of the neptunium concentration in aqueous and organic phases after the extraction. UV-Vis/NIR spectroscopy measurements in the wavelength range of 950-1030 nm were carried out at pH 4, 5 and 7 with 237Np(V) concentrations of 2∙10-5 - 6∙10-5 M. The maximum of the absorption band of the neptunyl aqua ion (NpO2+) at 980 nm shifts with increasing ligand concentration to 983 nm (NpO2Prop) and 986 nm (NpO2Lact) while its absorption intensity decreases. Slope analysis of the results yields a 1:1 Np(V) complex formation for propionate and lactate at the given pH values. In the extraction experiment, the distribution ratio of [Np-org]/[Np-aq] decreases with increasing ligand concentration. Both methods provided similar conditional complexation constants at ionic strength of 0.5 M NaCl: log Kc (spec) = 1.09±0.1 and log Kc (LLE) = 1.04±0.02 for NpO2Prop; log Kc (spec) = 1.75±0.1 and log Kc (LLE) = 1.85±0.01 for NpO2Lact. The value for the lactate complex is comparable with a value from literature: log Kc (spec) = 1.78±0.03 for NpO2Lact I = 0.3 M [2]. The complexation strength of propionate is similar to the acetate complexation expressed in a similar complex formation constant of log Kc (spec) = 1.05±0.04 for NpO2Acet at I = 0.3 M [2]. The work will be extended to different ionic strengths and elevated temperatures in the near future. References: [1] Y. Inoue, O. T. (1982). "Solvent extraction of neptunium (V) by thenoyltrifluoroacetone and 1,10-phenanthroline or tri-n-octylphosphosphine oxide." Radiochimica Acta 31: 193-196. [2] R. C. Moore, M. G. Bronikowski (1999). "Thermodynamic modeling of actinide complexation with acetate and lactate at high ionic strength." Journal of Solution Chemistry 28(5).
Speaker: Mr Aleksandr Vasiliev (Moscow State University)
• 150
Superheavy Element Chemistry Through Highly Accurate Small-Core Pseudopotential Model
Recent advances in first-principle based studies of superheavy element (SHE) chemistry using the new accurate small-core pseudopotential model are summarized. This model accounts for the finite nuclear size and effectively incorporates most relativistic effects described by the all-electron Dirac—Coulomb—Breit model (including the bulk of Breit interactions) and enables explicit correlation of both valence and subvalence electrons. It provides thus a good basis for attaining optimal accuracy/cost ratio in the cases of large and strongly interfering relativistic and correlation effects characteristic for the SHE compounds. Depending on the size of systems under study and required accuracy, high-level relativistic wavefunction theory (mainly coupled-cluster) and density functional theory methods or their combinations were used to solve the electron correlation problem. Synthesis and chemical identification of new superheavy elements is of top interest during the last decade. Since the thermochromatography on gold has been proved to be a unique method of chemical detection of heaviest elements, main attention was paid to the description of the SHEs – gold interactions. Adsorption energies of SHEs on gold surface were estimated using the cluster model. Its reliability was improved by monitoring charge distributions in the vicinity of the adsorption site and taking into account the effects of relaxation of the cluster compatible with its embedding into the crystal. In some cases the results differ significantly from those of previous theoretical studies. For instance, the new estimates of element 113 and element 120 on gold adsorption energies (1.0-1.2 eV and 2.5-2.7 eV respectively [1, 2]) are recommended. Further development of the SHE “chemical” identification techniques may benefit from having a broader view of their chemical properties. We performed systematical relativistic calculations of molecular structures and energetics of presumably stable binary compounds of SHEs with the most common light elements. We focus on the properties of element 120, copernicium (E112) and flerovium (E114) which are expected to display particularly strong relativistic contraction and stabilization of the filled s or p1/2 subshells. The obtained results along with the similar data for the homologues of SHEs were visualized through the “chemical graphs” which reflect the main trends in changing basic gas-phase chemical properties of the elements in the given group of the Periodic table and demonstrate the specificity of SHEs [3]. The work is partially supported by the RFBR (grants # 13-03-01234, # 13-03-01307 аnd # 13-03-12252-ofi_m-2013). Thanks are due to Prof. C. van Wüllen for supplying us with his relativistic DFT code. The calculations were performed at MCC NRC “Kurchatov Institute” (http://computing.kiae.ru/). 1. A.A. Rusakov, Yu.A. Demidov, A.V. Zaitsevskii // CEJP (Rapid Comm.), 11, 1537-1540 (2013) 2. Yu. Demidov, A. Zaitsevskii and R. Eichler // PCCP (Rapid Comm.) 16, 2268-2270 (2014) 3. Yu. A. Demidov, A. V. Zaitsevskii // Radiochemistry 55, 461-465 (2013)
Speaker: Mr Yuriy Demidov (PNPI)
• 151
Synthesis and Research of the Hydrated Oxide U(VI) with General Formula UO3•2.25H2O
A new method of synthesis of schoepite [(UO2)8O2(OH)12](H2O)12(UO3•2.25H2O) has been proposed in this work. Dehydration process of the synthesized compound has been studied, the state and role of H2O in the structure has been established by mean of high-temperature X-ray diffraction, IR spectroscopy and thermography. The transformation processes of schoepite in other forms of the hydrated oxide U(VI) have been investigated. The individual crystalline phases of schoepite were synthesized by the two stages process. Earlier UO4•2H2O was prepared and decomposed into UO3 at 200°С. Thereafter this freshly obtained uranium (VI) oxide was hydrated by water vapor at 100°С. An IR spectroscopic study was carried out in order to evaluate the functional group composition, the state of H2O molecules and the state hydroxide groups in the structure of schoepite. The IR spectrum of UO3•2.25H2O contains three groups of absorption bands. Among these bands there are vibrations of H2O molecules, UO-H group and uranyl bonds. In schoepite all H2O molecules forms two types of H-bonds. First type of bonds is formed by the interaction of H2O molecules with each other. Interlayer H2O molecules and hydroxide groups, which are included in the structure of layer, interact and form other type of H-bond. The average intensity pick of ν (UO-H) appears in the spectrums at 3356 см-1. Corresponding bands of δ (U-O-H) vibrations are intensive ones at 997 см-1. For detailed determination of the schoepite structure and its resistance to high temperatures, a thermographic investigation has been carried out. Two Н2О molecules is removed [(UO2)8O2(OH)12](H2O)12 in one stage according to the first endotherm effect at 80–116°С. A new crystalline phase of meta-schoepite [(UO2)8O2(OH)12]•(H2O)10 is formed as a result of these processes. This compound is stable at room temperature. The process of the meta-schoepite thermal decomposition occurs in one stage according to the second endotherm effect in the temperature range of 118–156°С. The dehydration product ([(UO2)8O2•(OH)12](H2O)2) could not be obtained as the individual phase, because two Н2О molecules per formula unit of the compound are insufficiently for binding of the layers in the stable formation. At intermediate values of from 2 to 10 compound [(UO2)8•O2(OH)12](H2O)n should be regarded as a crystalline phase of variable composition, related to the class of solid solutions with different content of molecular water. The dehydration product with formula [(UO2)8O2(OH)12](H2O)2 (UO3•H2O) isomerizes in to α-modification of uranyl hydroxide α-UO2(OH)2. The condensation of hydroxide groups in α-UO2(OH)2 and formation UO3 occurs at the third endotherm effect at 289–361°С. This oxide decomposes to U3O8 at 500°С. Thus schoepite, meta-schoepite and uranyl hydroxide contain the similar structure units such as Н2О molecules, uranyl and hydroxide groups. Different combination of these structural units is a reason of existence of a variety of chemical forms of UO3•nH2O.
Speaker: Ms Kseniya Chaplieva (Aleksandrovna)
• 152
Synthesis and study of Lithium Triuranate Li2U3O10⋅6H2O
In this work, a method of synthesis of lithium triuranate hexahydrate Li2U3O10⋅6H2O is described. The chemical and functional composition of this compound has been investigated; its crystallographic characteristics have been determined; the state of Н2О and its role in the formation of the structure have been studied. Synthesis of the investigated compound is а reaction of shoepita UO3•2.25H2O with aqueous solution of lithium nitrate under hydrothermal conditions at 200OC. The synthesized lithium triuranate hexahydrate is an easily reproducible individual crystalline compound. The X-ray diffraction picture contains a series of reflections from planes with indices which, in combination with an intense reflection peak at 2θ= 12.04°, indicate a typical layered structure of the triuranate. For evaluation of its functional composition of Li2U3O10⋅6H2O, we have performed the IR spectroscopic research. The spectrum contains two groups of vibrations associated with Н2О and uranyl group. The vibrations of Н2О are very characteristic. The band of δ(Н2О) vibrations at 1620 cm–1 is not split. Due to the participation of Н2О molecules in the formation of the branched system of H-bonds, the bands of vibrations νs and νas represented in the spectra by a broad and intense band with faint maxima at 3511 and 3414 cm–1 . On the whole, all Н2О molecules in the IR spectrum of Li2U3O10⋅6H2O retain their vibrational identity. The vibrations of the uranyl group are represented in the spectrum by the only band νas at 917 cm–1, which is typical for the seven-fold coordination of uranium(VI) in its uranium–oxygen polyhedron. The absence of the band allows us to consider the uranyl group as having a linear and the equal-shoulder configuration. To specify the state of Н2О in Li2U3O10⋅6H2O and to estimate its position in the structure, we have performed thermographic study. According to the first effect in the DTA curve at 162°С, the elimination of four Н2О molecules per Li2U3O10•6H2O formula unit proceeds in a single stage. The elimination of the two additional Н2О molecules also proceeds in a single stage, but at a higher temperature 393°С. The dehydration process is completed at 393°С by the total destruction of the crystal structure and the transition into the amorphous state. The crystallization of Li2U3O10 over wide time and temperature ranges occurs above 393°C.
Speaker: Ms Elena Kostrova (Leonidovna)
• 153
The investigation of uranyl vanadates state in the saturated aqueous solutions
The state of uranyl vanadates with formula Ak(VUO6)k*nH2O (Ak –elements of the I-III groups of Periodic system) was investigated in aqueous solutions. The study of these compounds are interested because of their low soluble in aqueous solutions and the compounds are likely to form at the contact with the nuclear waste in the environment, therefore Ak(VUO6)k*nH2O can be used to bind uranium. Thereby it is necessary to investigate the state, stability, solubility, conversion of uranyl vanadates in aqueous solutions. It is shown that pH has the most significant impact on the state of uranyl vanadates in heterogeneous water-salt systems. The pH of the aqueous solution defines the range pH of uranium existence, the type and solubility of the secondary phases. On the whole, it was established that uranyl vanadates are inconvertible at the contact with the aqueous solutions in the wide acid-base range. Their structure and composition preserve in heterogeneous water-salt systems at pH from 1-2 to 11-12. Out of the pointed interval the structure of uranyl vanadates destructs and compounds with another composition and structure form and are in the equilibrium to the aqueous solution. A type of formed compounds depends on pH. In acidic media at pH ≤ 1-2 initial compounds convert into the amorphous V2O5. At pH > 11-12 the equilibrium solid do not contain Ak(VUO6)k*nH2O and consist of the Ak(OH)2 and Na2U2O7 mixture. The solubility products were calculated using the solubility data of the system for the pH intervals, where uranyl vanadates saved their composition and structure. The type of interlayer atom do not significant influence on the solubility of compounds. The solubility of Ak(VUO6)k*nH2O has been determined, it changes on the several orders from 10-6 – 10-8М in the subalkali solutions to 10-2 - 10-3M in the acid and the strongly alkaline media. It was established that the solubility products values for all investigated compounds decrease according to the interlayer atoms radius increasing. The solubility products allow to calculate the thermodynamic functions of the heterogeneous system components, to plot speciation diagrams of uranium (VI) and vanadium (V) in the aqueous solution and solid phases. The solid phase and aqueous solutions diagrams and solubility curves of uranyl vanadates at the range pH 0-14 were plotted. This research makes it possible to use experimental data to solve practical problems, and allows to obtain the important information about the state of the saturated aqueous solutions and the secondary phases of studied heterogeneous systems in the isobaric-isothermal conditions.
Speaker: Ms Anna Eremina (Alekseevna)
• 154
Theoretical Chemistry Study of Uranyl (VI)-Sulphate complex species
This theoretical study of several possible complex species of the general formula ([UO$_2$(H$_2$O)$_a$($\eta^1$-SO$_4$)$_b$($\eta^2$-SO$_4$)$_c$]$^{2-2(b+c)}, 0 ≤ b + c ≤ 4, 5 ≤ a + b + 2c ≤ 6, [UO$_2$(H$_2$O)$_2$($\eta^1$-SO$_4$)($\eta^2$-SO$_4$)]$^{2-}$depicted at the Fig. 1.) aspires to the theoretical prediction of stability constants$\beta$°, thermodynamical properties (i.e.$\Delta$G° and$\Delta$H°) and their dependance on the temperature. Equilibrium geometries in the ground state and several excited electronic states, vibrational modes and frequencies, moments of inertia, vertical transition energies important to the UV-VIS absorption, excitation and emission/fluorescence spectra were calculated as well. Our study is also the first step towards the molecular-dynamical study searching seeking for another approach to predict$\Delta$G°,$\Delta$H° and log$\beta\$° and, more importantly, to predict the fluorescence lifetimes (or more generaly - the TRLFS spectra) and their dependance on the temperature and ionic strength (or, more generaly - the solution composition). The comparison of all of the ab initio predicted and experimentally obtained quantities is included. Both, the purely ab initio methods based on the Dirac(-Breit) equation (DHF, MCDHF, KRCI, CCSD) and the density functional methods (DFT (b3-lyp/def-SVP), TDDFT (bh-lyp/def-SVP)) were used. This work tries to reproduce and further develop the study of uranyl-sulfates done by Jakub Šebera [1].
Speaker: Mr Jakub Visnak (Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague)
• 155
UO2, NpO2 and PuO2 preparation in aqueous nitrate solutions in the presence of hydrazine hydrate
Modern nuclear power engineering is focused on the use of fast neutron reactors (FNR). These reactors run on the mixed uranium-plutonium oxide fuel (MOX) and allow one both to use weapon-grade plutonium as a fuel and to transmute formed long-lived actinide isotopes. In this connection there arises the problem of a creation of economically effective and environmentally acceptable technology of the MOX fuel production. The separation technologies of U and Pu from spent nuclear fuel (SNF) complete nitrates forms of these elements. As a rule, uranium and plutonium are isolated from the solutions by ammonia and oxalate precipitation, respectively. Isolated compounds are used for the production of powders of uranium and plutonium dioxides or nitrides for MOX fuel synthesis. For example powders of the mixed oxides are produced by precipitation from the solutions of mixtures of ammonium diuranate and plutonium hydroxide or by combined co-precipitation ammonium uranylplutonyl carbonates followed by filtration, drying and ignition of the compounds obtained at 800 °C under reducing conditions of argon-hydrogen atmosphere. The disadvantages are obvious - the complexity of the implementation and the multi-stage processes. The development of new technologies for MOX fuel involves fixing the problem of denitration of actinides aqueous solutions. There exist the methods of direct denitration and by using reagents. Gaseous hydrogen, formaldehyde, formic acid, urea, sugar, ethyl alcohol et al. are used in the methods of reagent denitration. This work presents data on thermal denitration of U, Np, Pu solutions by hydrazine hydrate to produce individual and mixed oxides of these elements. Simple and effective method of preparation of homogeneously mixed U, Np and Pu dioxides from aqueous nitrate solutions containing a mixture of the actinides was developed. The method is to use a thermal denitration of solutions of U, Np and Pu nitrates in the presence of hydrazine hydrate to obtain hydrated dioxides of these elements. It was established that the UO2xnH2O calcination results: • crystalline UO2 under inert or reducing conditions in the range of 280-800 °C; • UO3 in air atmosphere at 440 °C; • U3O8 at 570-800 °С. It was shown that thermolysis of the solution containing a mixture of uranium, neptunium and plutonium nitrates at 90 °C in the presence of hydrazine hydrate allows one to prepare hydrated dioxides (U, Np, Pu)O2xnH2O which on heating to ~300 °C transmogrify into crystalline (U, Np, Pu)O2 solid solution.
Speaker: Dr Sergey Vinokurov (Vernadsky Institute RAS)
• Poster Session - Radiation Chemistry
• 156
Approach of evaluation of influence of gamma and UV radiation on microorganisms in presence of some scavengers of OH radicals.
During irradiation of microorganisms in liquid media by gamma radiation, hydroxyl radicals are considered as one of the most dangerous agents. Elimination of these radicals by their scavengers (ethanol, methanol and potassium formate) should protect the cells. Comparison of two ways of interpretation of acquired data was performed. Dependencies of σ ( =(ln⁡(s0))/(ln⁡(s)), where s0 is fraction of cells surviving in suspension with no scavenger added and s is fraction of cells surviving in suspension with one of OH scavengers) and α (increase of survival) on scavenging efficiency (Q) were evaluated and compared. Besides, a method that allows to compare effects of gamma and UV radiation was developed. This procedure, permitting to determine the dose of UV light, is based on constant absorbance and continuous stirring of the sample during irradiation.
Speaker: Mr Jaroslav Červenák (CTU)
• 157
Chemical evolution studies: The radiation chemistry and thermal decomposition of malonic acid
Speaker: Dr Alicia Negron-Mendoza (Instituto de Ciencias Nucleares, UNAM)
• 158
COMPUTER SIMULATION OF DIFFUSION, ADSORPTION, DESORPTION, AND β - DECAY OF 89Br ON THE TUNGSTEN SURFACE
In course of construction of thermionic converter it is necessary to solve the problem of electrodes metal surface [1]. This paper presents the method and results of computer simulation of surface diffusion, adsorption, desorption, and β-decay of 89Br on the surface of single-crystal tungsten, in both case at the presence, and at the absence of 133Cs on it. The simulation of all the mentioned processes was carried out by solving the system of partial differential equation with the appropriate boundary and initial conditions. As a result of this simulation it was shown that: - principal amount of 89Sr hits the surface of the tungsten collector by direct adsorption from the gas phase and not at the expense of β-decay of 88Kr, 89Kr, 89Rb, 89mY and 89Y in the adsorption layer. - joint diffusion and desorption of 89Sr with the presence on the surface of 133Cs is faster than a single 89Sr. Literature 1 D.Yu. Lyubimov, I.I. Fedik, A.A. Shumilov, “Effet of fission products on the output power of thermionic EGC with communicating and separated fuel-element cavities and in interelectrode gap”, Atomic Energy, 2011, Vol. 110, № 6, p. 395-404. 2 Ya.E. Geguzin,“Diffusion by real crystal surface” in Surface diffusion and…, Nauka, Moscow, 1969, p. 11-77. 3 R.Ya. Kucherov, D.Yu. Lyubimov, L.G. Smirnov, et al., “Modeling physicochemical processes on the surface of niobium-oxygen collector in a thermionic”, Materialovedenie, 2002, № 7, p. 11-17.
Speaker: Mr Andrei Androsov (russian)
• 159
Containment surface interactions of gaseous elemental iodine and ruthenium tetroxide during severe nuclear accidents in LWRs
During severe nuclear accidents in LWRs several hazardous and radiotoxic gaseous fission products will be released from damaged UO2 fuel. Volatile iodine species (CsI, IOx, I2, org. iodides such as MeI) will be released and formed already in an early stage of a severe accident, while the release of volatile oxides of ruthenium (RuO3, RuO4) will require a rupture of the containment with a significant air ingress. Considerable amounts of released CsI and elemental iodine will dissolve in the water pools and steam. Remaining gaseous elemental iodine can be partly immobilized by sorption on the containment surface and structural materials (paint, Al, Cu, Zn). A fraction of the iodine will be physisorbed and thus can be rather quickly revaporised or washed off from the surfaces. Some of the iodine will be chemisorbed, like on copper and epoxy paint surfaces (Teknopox Aqua VA). Ruthenium tetroxide has a high affinity to deposit on all the available surface materials. It is a strong oxidizing agent and thus possibly affects the volatile iodine source term. Differences of the sorption behavior of RuO4 on plane and iodine covered surfaces have been investigated qualitatively and quantitatively, as well as the effects on the iodine revaporisation behavior.
Speaker: Mr Ivan Kajan (Chalmers University of Technology)
• 160
Natural metamict minerals as analogues of aged nuclear ceramic waste forms
Natural metamict U-Th-containing minerals are well known analogues of aged nuclear ceramic waste forms, which were affected by self-irradiation and chemical alteration under the conditions of geological environment. Main concern related to the behavior of radioactive ceramics during their long-term storage is the stability of radionuclide solid solution in the crystalline structure of durable host-phases. Self-irradiation may cause not only damage of crystalline structure of host-phase (its amorphization or metamictization) but also destruction of solid-solution and release of radionuclides in separate chemically mobile forms. We have studied two large (1-3 cm in size) and relatively homogeneous samples of natural fully metamict minerals: Y-Fe-niobate, (Y,Fe,U,Th)x(Nb,Ti,Ta)yOz (containing 1.0 wt.% ThO2 and 4.2 wt.% UO2) and lovchorrite, Na(Ca,Na)2(Ca,Ce)4TiO2F2(Si2О7)2 (containing 1.1 wt.% ThO2). No evidences of solid solution destruction as a result of metamictization were observed in these samples. Both samples: untreated and annealed at different temperatures in order to initiate recrystallization were analyzed in comparison by precise X-ray powder diffraction, electron microprobe (EMPA) and scanning electron spectroscopy (SEM). It was observed that annealing caused not only recrystallization of both samples but also destruction of initially homogeneous solid solutions with partial release of U or Th in the forms of separate phases. It was proposed that recrystallization of aged nuclear ceramic waste forms as a result of any possible natural process is not positive phenomenon as it was assumed before. Recovery of crystalline structure can be accompanied by essential release of radionuclides.
Speaker: Mrs Qiuxiang Cao (East China Institute of Technology, Guanglan Road, 418, 330013, Nanchang, Jiangxi, China;Saint-Petersburg State University, Universitetskaya emb. 7/9, 199034, St.-Petersburg, Russia)
• 161
Radiation Stability of CyMe<sub>4</sub>-BTBP and CyMe<sub>4</sub>-BTPhen in their Solutions in Cyclohexanone-based Diluents
Speaker: Jana Sočuvková (CTU in Prague, FNSPE, Department of Nuclear Chemistry, Prague)
• 162
Radiation Stability of Hydrocarbon Diluents of TBP in Two Phase System Used in SNF Reprocessing
Speaker: Dr Elena Belova (Russian academy of sciences A.N. Frumkin Institute of Physical chemistry and Electrochemistry RAS)
• 163
Radiolysis of Frozen Aqueous Solution of Methanol
Speaker: Prof. Sergio Ramos-Bernal (Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico)
• 164
Redox Behavior of Neptunium in Irradiated Aqueous Solutions of Nitric Acid in Presence of an Extracting Organic Phase
A reliable solvent extraction process for separation of neptunium from irradiated nuclear fuels depends upon the maintenance of a valence state amenable to complexation by tributylphosphate (TBP). However, radiolytic generation of nitrous acid in irradiated nitric acid solution may reduce extractable Np(VI) into non-extractable Np(V). One complicating factor that has so far not been well investigated is the influence of the presence of an extracting organic phase on the redox speciation and extraction of neptunium during radiolysis; hence, the rates and total yields of radiolytic reduction of neptunium were measured in varying concentrations of nitric acid, both in the presence and absence of a 30% TBP/dodecane organic phase. In the aqueous solution, greater concentrations of nitrous acid were produced at higher nitric acid, although this did not necessarily result in faster reduction rates for Np(VI). This is likely because of oxidation of Np(V) directly by nitric acid and by oxidizing radicals produced by radiolysis of aqueous nitric acid. The presence of the organic phase appeared to protect Np(VI) from reduction, perhaps due to complexation by TBP.
Speaker: Dr Martin Precek (Institute of Physics AS CR)
• 165
Stability Under Irradiation of Some Aminoacids
Homochirality of certain organic molecules essential for all living organisms, such as the L-amino acids and the D-sugars, has made the search for its origin an important issue in studies of the origin of life and evolution. Comets and asteroids are thought to include organic compounds imbibed in ices, rocks, and have been proposed as carrier of those compounds to the early Earth. Among the products detected in meteorites (carbonaceus condrites)are amino acids, which are key compounds for chemical evolution studies. The meteoritic amino acids are of the D and L optical isomers types with a lightly enantiomeric excess. The mechanism involved for this excess is still a debate. One theory involves the irradiation with high energy on racemic mixtures. The purpose of this work is to study the stability under irradiation of some amino acids (in solid state and in aqueous solutions). For this purpose, individual amino acids (L, D and D,L alanine, L, D and D,L serine and L, D and D,L phenylalanine) were exposed to different irradiation doses up to 90 MGy that is a dose higher than the calculated total dose that received a comet since it formation. The analysis of the samples was made by high performance liquid chromatography with a quiral column. The results show that the molecules under study presented great stability under gamma irradiation and the recovery is more than 60%. The support from CONACYT grant No.16857911 , PAPIIT grant IN110513 and Posgrado en Ciencias Quimicas is acknowledged. One of us (EA) was supported by a CONACYT fellowship.
Speaker: Dr Alicia Negron-Mendoza (Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM))
• 166
Thiacalix[4]arenes: radiation stability and Eu/Am extraction in synergistic systems with COSANs
This study deals with the effects of irradiation on the stability and extraction properties of thiacalixarenes1, the prospective liquid-liquid extractants for the extraction of actinides and lanthanides from aqueous solutions. Thiacalixarenes (T1, T2) dissolved in cyclohexanone and 1,2-dichloroethane were irradiated with 60Co gamma rays or accelerated electrons with energy of 4.5 MeV. The absorbed doses ranged from 0 to 100 kGy. The extraction properties towards europium and americium, as lanthanide and actinide representatives, were studied in synergistic systems. The combinations of two thiacalixarene extracting agents, three COSAN molecules and three diluents (chlorobenzene, nitrobenzene and 1,2-dichloroethane) were evaluated. For the determination of residual concentration, the HPLC method was used and compared with the assessment of the change of the D(Am) and D(Eu) values in solvent extraction experiments. The aqueous phase consisted of a solution of COSAN (chloro-protected bis(1,2-dicarbollide) cobaltic acid) in 0.1mol/l nitric acid; solutions of thiacalixarene T2 in 1,2-dichlorethane were used as the organic phase. Distribution ratios D for 152Eu and 241Am and their mutual separation factors were evaluated. The activity of aqueous and organic phase was measured via gamma spectrometer with HPGe detector. The results obtained from both methods correspond to each other and the decline in the extraction behaviour can be derived from the residual concentration determination and otherwise. Both thiacalixarenes seem to be more stable in the irradiated cyclohexanone samples than in the 1,2-dichloroethane samples which is in good agreement with the state that during cyclohexanone radiolysis less aggressive intermediates are produced comparing with the latter case. This work was performed under the auspices of Czech Science Foundation grant GACR 104-07-1242 and Ministry of the Interior of the Czech Republic grant VG20132015132. REFERENCES 1. Lhoták P.: Eur. J. Org. Chem., 2004(8), 1675.
Speaker: Irena Špendlíková (KJCH FJFI CVUT)
• 167
Time programming of mechanical and electronic properties of materials via self-irradiation phenomena : a theoretical study.
Speaker: Dr Valeriy Luchnikov (Institut de Science des Matériaux de Mulhouse CNRS)
• Poster Session - Radionuclides in the Environment, Radioecology Gallery

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• 168
129I in the Antarctic seawater measured by carrier free iodine separation and AMS
Due to low concentration of iodine in seawater, iodine carrier is normally added as carrier for separation of 129I from matrix using solvent extraction, this is not suitable for the determination of low level 129I in the seawater received less anthropogenic 129I such as those collected in south hemisphere including the Antarctic and deep seas, because of contribution of 129I in the iodine carrier to the sample during sample preparation. A simple co-precipitation method for separation of carrier free iodine from seawater for measurement of 129I/127I using accelerator mass spectrometry (AMS) has been reported by our group. In this work, some improvement of this method was completed to able to obtain better measurement uncertainty in AMS measurement. The results reveal that addition of small amount of carrier (0.1-0.2 mg) can significantly improve the measurement accuracy and precision. A certified seawater reference material, IAEA-418 (Mediterranean Sea water) has been successfully analyzed by utilizing the presented method and the concentration of 129I was measured to be 2.36×108 atoms L-1 in this sample, which agreed well with the certified value (2.28×108 atoms L-1), as well as the results measured by traditional solvent extraction by addition of 2 mg iodine carrier, indicating reliability of the developed method. Six seawater samples collected from the Antarctic in 2011 were analyzed utilizing the developed method. The results indicate that 129I/127I atomic ratios in the investigated area range from 0.7×10-12~9.9×10-12 with a mean of 6.1×10-12, which is close or slightly higher than the reported pre-anthropogenic ratio of 1.5×10-12. The main source of 129I in the investigated area might be attributed to the global fallout of both atmospheric nuclear weapons testing and long distance dispersion of fuel reprocessing releases. This is the first report of 129I in the seawater from the Antarctic, the results shed a light of feasible application of 129I as an oceanographic tracer application of 129I the Antarctic.
Speakers: Prof. Aldahan Ala (1) Uppsala University; 2) United Arab Emirates University), Prof. Hou Xiaolin (1) Institute of Earth Environment, CAS; 2)Technical University of Denmark), Mr Xing Shan (Institute of Earth Environment, CAS)
• 169
210Po and 210Pb in fur of domestic animals
The aim of the study was to determine 210Po and 210Pb in fur samples collected from 15 breeds of dogs Canis familiaris living in the northern Poland. The average values of analyzed radionuclides in analyzed dog fur ranged from 0.46±0.02 mBq∙g-1 to 15.05±1.13 mBq∙g-1 for 210Po and from 0.31±0.03 mBq∙g-1 to 9.82±0.53 mBq∙g-1 for 210Pb. The highest activities of 210Po and 210Pb were measured for small long-haired dog Maltese while the lowest in small long-haired Yorkshire terrier and Poodle toy. The values of the 210Po/210Pb activity ratio were calculated from 0.82±0.09 for Yorkshire terrier to 5.16±0.45 for Bolognese. Generally, both 210Po and 210Pb radioisotopes accumulation did not depend on dog sex. Higher values of 210Po and 210Pb were found in long and rough-haired dogs. Further, our experiments showed the hair from dogs living in villages contained more 210Pb than dogs living in the cities and dogs eating dry food accumulate more 210Po in their hair in comparison to fresh or mixed food eating dogs. The authors would like to thank the Ministry of Sciences and Higher Education for the financial support of this work under grant DS/530-8120-D384-14.
Speaker: Ms Karolina Szymanska (Faculty of Chemistry, University of Gdansk)
• 170
210Ро in Different Types of Teas
Speaker: Dr Natalia Gomzina (N.P.Bekhtereva Institute of the Human Brain, Russian Academy of Sciences (IHB RAS), St. Petersburg, Russia)
• 171
241Pu in seabirds
The paper presents unique data of plutonium 241Pu study in seabirds from northern Eurasia, permanently or temporally living at the southern Baltic Sea coast. Together 10 marine birds species were examined: 3 species of permanently residing at the southern Baltic, 4 species of wintering birds and 3 species of migrating birds; about 150 samples were analyzed. The obtained results indicated plutonium is non-uniformly distributed in organs and tissues of analyzed seabirds. Generally the highest plutonium concentrations were found in the digestion organs and feathers, next in skeleton, and the lowest in muscles. Among analyzed birds the highest 241Pu concentration was found in viscera, its activities in the digestive organs ranged from 9.7±2.5 µBqg-1 ww (13.0% of total 241Pu) in great cormorant (P. carbo) to 228±39 µBqg-1 ww (79.6% of total 241Pu) in velvet scoter (M. fusca). High 241Pu concentrations were also found in liver where ranged from 21±4 µBqg-1 ww in velvet scoter (M. fusca) (2.2% of total 241Pu) to 159±31 µBqg-1 ww in tufted duck (A. fuligula) and feathers where ranged from 15±4 µBqg-1 ww in great cormorant (P. carbo) (11.6% of total 241Pu) to 132±59 µBqg-1 ww (34.2% of total 241Pu) in common eider (S. mollissima). The main source of plutonium in analyzed marine birds was global atmospheric fallout as well as the Chernobyl accident, which was confirmed by plutonium activity ratios of 241Pu/239+240Pu as well as 238Pu/239+240Pu. On the basis of the average 241Pu concentrations in the southern Baltic Sea biocenosis components the plutonium content in marine organisms increases as: seabirds < fish < phytobenthos < phytoplankton < zooplankton < zoobenthos. The authors would like to thank the Ministry of Sciences and Higher Education for the financial support of this work under grant DS/530-8120-D384-14.
Speaker: Ms Karolina Szymanska (Faculty of Chemistry, University of Gdansk)
• 172
241Pu in the southern Baltic Sea ecosystem
Most contamination studies have focused on alpha emitting plutonium isotopes so far. 241Pu is less important in terms of its radiotoxicity than the α-emitting plutonium radionuclides 238,239,240Pu but is quite significant because of its huge contribution to the whole plutonium fallout. Our previous experiments on air samples indicated extreme increase of 241Pu amount in atmospheric dust in April 1986. The available information about the bioaccumulation and distribution of 241Pu in the Baltic Sea ecosystem and Poland territory is still very limited. The main purpose of the present work was to complete the present knowledge and estimate the further levels of the Baltic Sea environment contamination. The highest total 241Pu concentration in seawater was found in the Słupsk Bank (3.35±0.17 mBq∙dm-3) and this area had the highest concentration of 241Pu connected to suspended matter as well (1.94±0.12 mBq∙dm-3). High concentrations of 241Pu in the central part of the southern Baltic Sea can be a result of Baltic water circulation. The 241Pu activity in phytoplankton sample from the Pomeranian Bay was 1.06±0.09 mBq∙g-1 dw. Within zooplankton samples the highest 241Pu activity was found in samples from the central part of the southern Baltic (2.66±0.16 mBq∙g-1 dw) and from the Gdańsk Deep (2.64±0.70 mBq∙g-1 dw). In zooplankton samples, similar situation to seawater samples was noticed – the highest concentrations of 241Pu were found in the central part of the southern Baltic Sea, and similarly to seawater it could be a result of Baltic water circulation. Generally the data show significant differences in 241Pu concentrations among all the species examined. The highest values of 241Pu activities for whole organism were found in fish from Perciformes: benthic round goby (0.863±0.066 mBq∙g-1 ww) and pelagic perch (0.666±0.001 mBq∙g-1 ww). The lowest 241Pu activity was found in flounder (0.104±0.009 mBq∙g-1 ww). The plutonium was also non-uniformly distributed between the organs and tissues of the analyzed fish, especially pelagic herring and cod as well as benthic flounder. In sediments, the highest amount of plutonium was found in the middle parts of all analyzed sediments and came from the global atmospheric fallout from nuclear tests in 1958-61. The distribution of 241Pu in analyzed sediments samples was not uniform and depended on the sediment geomorphology and depth as well as on its location. The authors would like to thank the Ministry of Sciences and Higher Education for the financial support of this work under grant DS/530-8120-D384-14.
Speaker: Ms Karolina Szymanska (Faculty of Chemistry, University of Gdansk)
• 173
Activity of 210Po in the blood and urine of the residents of the Tricity agglomeration
Speaker: Mr Grzegorz Romanczyk (University of Gdansk)
• 174
Adsorption of Trivalent Lanthanides and Actinides by Marine Sediments
Knowledge of the chemical behaviour of (radio)toxic elements in natural/environmental systems is of fundamental importance for the performance of environmental impact assessments and the application of protection measures after possible contamination. The interaction of actinides with marine sediments is of particular interest because marine sediments constitute the final receptors for the majority of actinides (Th, Am, Pu). In order to study the chemistry of trivalent actinides (e.g. Am(III), Cm(III)) often trivalent lanthanides are used as analogues, because lanthanides in aqueous solutions are generally stable in the trivalent oxidation state, present similar chemical behaviour as trivalent actinides, are non-radioactive and posses useful spectroscopic/fluorescent properties. In this study we have investigated the interaction of Nd(III) and Eu(III) with two different types of marine sediments as a function of various parameters (e.g. pH, [M(III)]o, I, tcontact) to evaluate their effect and get more information on the adsorption of Nd(III) and Eu(III) by marine sediments. Sorption of Eu(III) by marine sediments from aqueous solutions of varying pH 4 – 6.5, fixed ionic strength of 0.1 M (NaClO4) and at room temperature has been studied by fluorescence spectroscopy (LFS). In this context, the effect of the particle coating with natural organic matter (NOM, e.g humic acid) on the adsorption properties of the sediment samples has also been studied. According to the experimental results the adsorption of Nd(III) and Eu(III) ions by marine sediments is (a) a relatively fast process (b) the adsorption data are well described by the Langmuir isotherm and (c) the adsorption properties (e.g. adsorption capacity, pH and ionic strength effects) of the different sediment types differ significantly from one another, depending on the (surface) composition.
Speakers: Mrs Ioanna Liatsou (Chemistry Department, University of Cyprus), Mr Ioannis Pashalidis (Chemistry Department, University of Cyprus), Mrs Maria Efstathiou (Chemistry Department, University of Cyprus)
• 175
Assessment of radiation and chemical risk in soils by radiometric and radioanalytical methods
Chernobyl and other nuclear accidents have demonstrated that high levels of radiation can result in impacts on plants and animals, however little is known about the long-term effects of chronic exposure on biodiversity or other population and ecosystem level effects. The overall aim of this study is to assess the impacts of chronic exposure to radioactivity and chemical pollutants. The study area on the Eastern Black Sea Region, Turkey has metal mining (Fe, Au, Ag, Mn, Mo, Cu, Pb and Zn) and industrial facilities, having elevated levels of both heavy metals, and affected the fallout of radionuclides after Chernobyl. Results for radiation and chemical pollution were obtained from the analysis of soil samples taken from 6 sites. All soil samples were measured for gamma, beta and alpha activities. Also, elemental concentrations of soil samples were determined by instrumental neutron activation analysis and X-ray fluorescence analysis. In summary, to assess radiation and chemical pollution risk, the possible impact of long-term behaviour of the radionuclides and elements in soil should be taken into consideration. This type of study does however need to provide regional background levels for these important radioactive and chemical pollutants. Additional studies will be performed to estimate the exposure for the diversity and plants from radioactive and chemical pollutants.
Speaker: Ms Ruveyda Kubra ILERI (Istanbul Technical UniversiIstanbul Technical University, Energy Institutety, Energy Instıtute)
• 176
Biological Barrier for Nitrate Ions in Environments
A. Safonov, V. Ilin, V. Tregubova, T. Babich, E. Zakharova, T. Nazina Disposing of the nuclear industry wastes in Russia and the U.S.A. in the 20th century have led to significant amount of storages not equipped with appropriate effective/protective barrier systems. This pose risks of environmental pollution through dissipating harmful macrocomponents and radioactive nuclides. The basic RW macrocomponent are nitrate ions present at concentration levels from 10 to 350 g/dm3. These are rather toxic for ecosystem for the and are characterized by high migration level. The factor that can significantly impact to the migration profiles of nitrate and metals in the environment is the influence of biochemical processes. The purpose of this work is to create a barrier for the immobilization of nitrate ions in subterranian freshwater through the intensification of biochemical processes by organic matter around the artificial pond – surface repository B-2 with LRW at the Siberian Chemical Combine. It will be the part of the existing barrier system of the conserved repository B-2 at Siberian Chemical Combine. Nowadays there is new geochemical barrier based on silicate polymers in groundwater around the conserved repository. It can block main radionuclides with very high efficiency, but can’t slow-down the nitrate ion migration risk. The concentration of nitrates in groundwater around the conserved repository can crease up to 5000 mg per liter. The essence of the biobarrier method is to stimulate the vital processes of autochthonous (indigenous) microorganisms leading to the destruction of nitrate ions to ecologically safe molecular nitrogen by injecting to contaminated zone as organic substrates into groundwater around the repository. In laboratory conditions, indigenous bacteria of groundwater samples were proved to be able to decrease nitrate concentration from 3-5 g/l to 10-15 mg/l when were amended with acetate, sucrose, lactate, or glucose in concentration 1-5 g/l as electron donor and carbon source. These results are the scientific basis for the development of biobarrier technology. This biotechnology could improve the existing barrier system of repository B-2. The project was supported by grants: Russian Foundation for Basic Research (№ 13-04-92105 and 14-03-00067)
Speaker: Mr Alexey Safonov (Frumkin"s Institute of Physical Chemistry Russian Academy of Science)
• 177
Catalytic wet oxidation of metal ion complexing agents by H2O2 using homogeneous and heterogeneous Fe (III) species
A large amount of liquid radioactive wastes are formed during nuclear power plants operating. Radionuclides contained in the wastes are predominantly in the form of stable complexes with organic ligands, such as EDTA, citric and oxalic acids, which complicates the heavy metal separation. Concentrating and processing of liquid radioactive wastes can be greatly simplified after the removal of these organic compounds. Сatalytic wet oxidation of complexing agents by H2O2 using Fe (III) species is a promising way for radioactive waste purification. The presenting work considers a method of catalytic wet hydrogen peroxide oxidation (CWHPO) of EDTA using homogeneous and heterogeneous Fe(III) species. The solutions of mono- and polynuclear hydroxo complexes of Fe (III) have been obtained and studied as homogeneous catalytic systems. Several types of Fe (III) containing zeolites ZSM-5 with different particle morphology and texture, including nanozeolites and hierarchical zeolite, have been synthesized and tested as heterogeneous catalysts. The activity in CWHPO of different Fe (III) species was measured by barometric cell method and total organic content determination. In homogeneous 1 mM Fe (III) catalytic system the highest hydrogen peroxide decomposition rate was observed at pH = 2.5 when mononuclear Fe(III) hydroxo complexes were predominant. The reaction rate was found to be decreased at pH = 1.5 and 3.0 when hydrated and polynuclear hydroxo complexes were formed, respectively. At pH > 3 Fe (III) hydroxide precipitated and the reaction rate was negligibly low. Unlike homogeneous system zeolitic one allows proceeding the reaction at a significantly wider pH range. Heterogeneity of the Fe (III) catalytic sites in the zeolite appeared to result in effective use of the hydrogen peroxide and a deep oxidation of a substrate. A comparative study of stability and activity of Fe (III) species supported onto the zeolite and amorphous SiO2 has been made in oxidation of low and high molecular weight organic subtances by H2O2. Catalytic site protection by zeolitic matrix plays a key role in the reactions and could be potentially explored for development of technology for purification of waste water from nuclear power plants.
Speaker: Ms Vera Labko (Joint Institute for Power and Nuclear Research - SOSNY, National Academy of Sciences of Belarus)
• 178
Cesium-containing complex oxides of the pollucite structure. Synthesis, properties, preparation of ceramics with high relative density and its radiation tests
Complex oxides with the structure of the mineral pollucite (CsAlSi2O6) represent a large group of compounds and they are basic for the development of materials for different purposes, including immobilization of cesium from waste of radiochemical industries and preparation of medical sources radiation. The number of such oxides has increased significantly basing on isomorphism of atoms in the crystal lattice and calculations modeling compounds of phosphorus-containing phases [1]. Isomorphic substitution of aluminum by boron leads to the increase of cesium mass fraction and growth of the specific activity of the compound in the case of a radioactive isotope. Inclusion of boron in the phosphorus-containing pollucite-like phases provides new possibilities for the development of materials for nuclear medicine (boron neutron capture therapy, BNCT) and ceramics - neutron absorbers. Oxides with pollucite structure containing boron and aluminum Cs[MgR0.5P1.5O6], where R = B and Al, were synthesized using a sol-gel process, and they were characterized by X-Ray diffraction. Structural studies for obtained compounds were performed (Rietveld refinement). The thermal expansion was studied by using of the methods of high- and low-temperature X-Ray analysis at temperatures range from -100 to 800 °C (α = (7.3 - 8.6)·10-6 deg-1), thermal (tested up to 1200 °C) and hydrolytic stability (T = 90 °C, 1.46·10-5 g/(cm2•d)) were studied also. The obtained compounds were used for synthesis of the ceramics by spark plasma sintering. The relative densities of ceramics were up to 98 % [2]. We found that the complex oxides – analogues of pollucite - have high chemical and radiation stability. The obtained ceramic materials were irradiated with 132Xe26+ ions (E = 167 MeV) in the fluence interval from 6•1010 to 1•1013 cm-2. The amorphization took place at a fluence of 1.2•1012 cm-2. The conditions of the metamict form transition into the crystalline form on heating were found. The crystal-chemical modeling of isostructural compounds was carried out with a deficit of cesium in the cavities of the structure of the general formula Cs1-x[Mg1+x-yR0.5-2x +0.5yLi0.5yP1.5+xO6], where R = B, Al; 0 ≤ x ≤ 0.2; 0 ≤ y ≤ 0.8. References: 1. Loginova E.E., Orlova A.I., Mikhailov D.A. et al. // Radiochemistry, 2011. V. 53. № 6. P. 593-603. 2. Orlova A.I., Troshin A.N., Mikhailov D.A. et al. // Radiochemistry, 2014. V. 56. № 1. P. 98-104.
Speaker: Mr Aleksey Troshin (Lobachevsky State University of Nizhni Novgorod)
• 179
Colliders and their Possible Georadiochemical Effects on the Environment
A dangerous factor is considered, which may precede the formation of black microholes, strangelets, magnetic monopoles and other objects in colliders, – the probability of turning the Earth into the "iron planet" or the flow of iron asteroids and meteorites. Proceeding only from real experimental evidence and theory-based provisions: 1) the quark-gluon plasma is already an experimental fact, 2) the dependence of the binding energy per nucleon from the number of nucleons in the nucleus is both experimentally and theoretically accurate, so we can assert that at the present moment the technical conditions for an uncontrolled conversion of all the chemical elements in the elements of Fe-Ni-Co group are already established, with the probability of catastrophic consequences for the Earth still extremely low, but 3) the possibilities of colliders are growing at a high speed and the dangerous threshold can be overcome in a very short time. A special group, established by CERN to evaluate the safety of experiments, presented a report which states that the Large Hadron Collider is not dangerous. The other dangerous process, which may occur from the uncontrolled formation of quark-gluon plasma of large volume and density in the conditions of the CERN experiment, is not considered at all. During this process, any substance turns into a cloud of elementary particles, which will condense in the process of cooling into the most energetically favorable state – the elements of the iron subgroup, which have the greatest values of the binding energy of the nucleons in the nucleus. The released energy will support this process till the complete conversion of all the chemical elements of the substance into the elements of the iron subgroup. It is believed that the first experimental results on the quark-gluon plasma were obtained in 1990 at CERN Super proton synchrontrone (SPS) (the concept of a fireball has deeper historical roots [1] and appeared for the first time in the physics of cosmic rays). Then, in 2000, also at CERN, the discovery of this "new state" of matter was announced. In the colliders, the energy of particles and the density of their torrent are continuously increasing, which naturally leads to a more "hot" chromoplasma, and to the increase of its volume and density. According to the prevailing ideas of today, the unlimited expansion of the fireball is very unlikely, but there are other opinions. For example, Academician E. Feinberg believed that the lifetime of fireballs is greatly underestimated [1]; Heisenberg’s calculations were already giving the abnormally high cross-section of their formation [2]; and Fermi has long ago presented the scheme which allows a fireball to expand unlimitedly in the flow of the accelerator [3]. The works of B.L. Ioffe were also published [4], which presented the abnormal parameters of the fireball, significantly different from L.D. Landau’s calculations [4]. The probability of formation of an abnormally large fireball could be significant. The reaction of "ferruginization" may obtain a global or nearly global nature. The possible protective measures to prevent the probable future catastrophe are being considered, as well as the hazardous geotectonic conditions of the experiments at CERN. 1. ФейнбергЕ.Л.- Усп.Физ.Наук,Т.139,вып.1,1983,с.3-49; 2. Heisenberg W. - Zs. Phys., 1952, Bd. 133, S. 65; 3. F e r m i E.-Phys. Rev., 1951, v. 81, p. 683 ; 4. Иоффе Б.Л. - ЖЭТФ,1974,т.20,вып.6, с.360-362
Speaker: Mr George Ryazantsev (B.)
• 180
Comparative study of radioactivity in NORM samples using ICP-MS and Instrumental Neutron Activation Analysis
Speaker: Dr Jong Myoung Lim (Korea Atomic Energy Research Institute)
• 181
Comparative study of the thermal, hydrolytic, radiation stability and mechanical properties of Cs, Ba, Sr, and Ln-containing ceramic materials for radiochemical problems and applications.
Knowledge of the behavior of materials in radiation fields need if ones are elaborated for radwaste immobilization. Also it is important to prepare a ceramic with high density for aims: medical, research and material science problems, consolidation and transformation of radwaste. Among these materials deserve special attention mineral-like. Natural "experience" shows the ability to save (stability) of mineral-like materials under the influence of heat, pressure, hydrolytic solubility, radiation fields in a long time. Used for a long time methods for the synthesis of ceramics (cold pressing with following hightemp firing; multistage hot pressing) have several disadvantages: prolonged exposure to high temperature, low relative density of the resulting product, multi-stage processes, high energy and time costs. This work focuses on the development and multitasks application of new methods for the synthesis of high-density ceramics (Spark Plasma Sintering), reducing temperature, duration of the process and the number of steps on the example of monophase polycrystalline compounds. The objects of research were following compounds: Ca0.25Sr0.25[Zr2(PO4)3] (NZP-type); CsBa(Sr)[Fe2(PO4)3], Cs2[Mg2(WO4)3] (langbeinite type); NdPO4 (monazite type); Y(1-x)GdxPO4 (x=0, 0.05, 0.25; xenotime type); Cs0.875Ba0.125Li0.125Zn0.875Al0.5P1.5O6 (pollucite type). This chemical compositions were choose as stable mineral-like matrixes, containing Cs, Ba, Sr, Ln jointly or separately. At the first stage we obtained the samples of composition as powders by using the sol-gel process. Step by step the gel formed and then powders were heated, dispersed and examined by X-Ray analysis. Then ceramics on the base of compounds named were sintered by Spark Plasma Sintering (SPS) method. Obtained powders and ceramic pellets were tested for thermal stability up to 1350 °C, hydrolytic stability in distillated water (20 and 90-100 °С (Soxhlet extractor, 7-28 days). Prepared cylindrical tablets (d=10, 20 mm) were irradiated with accelerated Xe-ions (E=167 MeV) stream at 6•1010 - 1•1013 fluences (1/sm2). The experiments were carried out at room temperature on the IC-100 FLNR JINR (Joined Institute of Nuclear Research) cyclotron. All compositions were stable after heating up to 1100 °C. High relative density was reached for all compounds by using SPS method for 0-5 min: 99,6-99,9 % (NZP); 96,2-99,9 % (langbeinite); 98,3 % (monazite); 98,8-99,9 % (xenotime); 99,9 % (pollucite). Ceramic materials with NZP and pollucite-like structure were stable after radiation till 1•1013 fluences (1/sm2) [1, 2]. 1. A.I. Orlova, V.Yu. Volgutov, D.A. Mikhailov et al. // J. Nuc. Mat., 2014, vol. 446. P. 232 – 239. 2. A.I. Orlova, A.N. Troshin, D.A. Mikhailov et al. // Radiochemistry, 2014, Vol. 56, No. 1, pp. 98–104.
Speaker: Mr Dmitriy Mikhailov (Nizhny Novgorod State University)
• 182
Composite Dust-Suppressing Coatings Containing Nanosized Sorbents Selective to Cesium, Cobalt, and Nickel Radionuclides
Here we report on development, characterization and performance evaluation of new materials based on selective to radionuclides nanosized sorbents stabilized in water dispersible nanoparticles (latexes). These new materials can be applicable as fixatives (dust suppressors), when latexes are film-forming, and as colloid stable sorbents for decontamination of solid bulk materials, when any type of latex, preferably containing carboxylic groups on the surface, is used. Two different series of polymeric nanoparticles were synthesized and tested as a polymer matrix for inorganic sorbents immobilization. The first type of particles was based on polystyrene and composed of polystyrene either pure (homopolymer) or copolymerized with different amounts of acrylic acid in order to obtain carboxyl-functionalized latex particles. The second type was poly(silane acrylate)-based copolymer nanoparticles, consisting from butyl acrylate, methyl methacrylate, polymerizable silane and functional comonomer (either methacrylic acid or aminoethyl methacrylate hydrochloride). All particles were synthesized in direct (oil-in-water) miniemulsion system by free-radical (co)polymerization. As selective inorganic materials colloidal SnO2 and MnO2 with mean particle size 10 nm and 200 nm, respectively, have been synthesized. Co(II) ferrocyanides were synthesized directly in the presence of carboxylic latex particles. Composites containing SnO2 nanoparticles selective to radionuclides of nickel and cobalt have been prepared using carboxylic and aminolatexes as a martrix, the maximum loading degree was about 60 mg of SnO2 per 1 g of latex. Sorption properties of composite latex/inorganic sorbent materials have been investigated toward 63Ni, 57Co (SnO2), 137Cs (Co (II) ferrocyanides), 90Sr (manganese oxides) in the presence of competing ions. Distribution coefficients up to 105 ml/g were reached for cesium radionuclides and for nickel and cobalt radionuclides on SnO2 in NaNO3 solutions The highest distribution coefficients of 90Sr (~3500 ml/g) in the presence of competing Ca2+ ions (0.1 g/L) were reached for manganese oxides. Dust suppressing formulations based on film-forming poly(silane acrylate) latexes containing Co(II)ferrocyanide and poly(silane aminoethyl) latexes containing SnO2 have been prepared and drop casted on model contaminated sand. The leaching of 137Cs and 57Co radionuclides from coated sand surface was efficiently suppressed (leaching degree below 1%), when the content of Co(II) ferrocyanide and SnO2 in composite coatings was as low as 1.3•10-6 mol/cm3 and 8.3•10-4 mol/cm3, respectively. Acknowledgements: Financial support for ERANET-Russia project (STProject-144) of the 7th EU Research Framework Programme is gratefully acknowledged.
Speaker: Dr Dmitry Marinin (Institute of Chemistry FEBRAS, Vladivostok, Russia)
• 183
Decreasing of Transfer of Caesium and Strontium Radionuclides from Soil to Vegetation
Speakers: Dr Anna Voronina (Ural Federal University), Mrs Marina Blinova (Ural Federal University)
• 184
Developing of a method of determination of concentration and isotopic composition of thorium in natural waters in radiation monitoring
Determination of the isotopic composition of natural radionuclides in natural waters is an integral part of radioecological monitoring. A full analysis of thorium radionuclides should solve two problems: determination of analytical concentration and isotopic composition. The main problem in the analysis of fresh water with low thorium content is preconcentration step; for samples with a high salt content and the complex composition it is removal of the most non-radioactive contaminants and alpha-emitters, e.g. uranium, preventing the preparation of high-quality source for alpha spectrometry. The aim of this work is to develop a thorium preconcentration step for large volumes of natural water. Th-234 was used as tracer in all experiments. Coprecipitation with iron hydroxide (III) followed by precipitation on cellulose in frontal chromatography condition was choosed for preconcentration of thorium. Theoretical and experimental modeling of thorium coprecipitation with iron hydroxide was performed. Calculations of solubility of thorium hydroxide have shown that its own hydroxide phase is not formed in range of concentrations typical for natural waters. Therefore, coprecipitation with carrier (iron hydroxide) is the only possible way for thorium preconcentration. Processes of iron hydroxide precipitation and thorium coprecipitation with iron hydroxide from freshwater were studied by ultrafiltration method in dependence on pH, concentration of the thorium and iron (III). To isolate the precipitate of iron hydroxide, which contains thorium, we proposed filtration through a nozzle in frontal chromatography condition. Cellulose was used as a nozzle. The study allowed to determine conditions thorium preconcentration that provide thorium yield (98 ± 8) %: the concentration of the iron (III) is 100 mg / l; pH 6.5-7.5; sediment formation time - 1 hour , the flow rate through column with filtration nozzle ~ 130 ml/min*cm2 . Weight of nozzle depends on volume of the sample. The ratio of height to diameter of the column is not less than 1:10. Extraction of thorium from filter nozzle by ammonium oxalate solution was performed under dynamic conditions. The method of coprecipitation with cerium fluoride was used for preparation of samples for alpha-spectrometric determination of thorium isotopes. Coprecipitation method with further separation of the precipitate by ultrafiltration was selected due to the fact that uranium(VI) remains in solution under these conditions. By fluoride precipitation the quality of the sample depends on presence of calcium in the sample, forming a crystalline precipitate. Therefore, solubility of cerium, thorium and calcium fluorides with taking into account hydroxycomplexes was calculated to optimize the conditions for sample preparation for α-spectrometric determination of thorium isotopes. The results have shown that precipitation of calcium fluoride does not occur, while thorium and cerium fluoride will be precipitated when concentration of fluoride ions was 1,8∙10^-5 mol/l ≤ CF- ≤ 5,0∙10^-3 mol/l. Optimal concentrations of cerium nitrate and hydrofluoric acid, providing a quantitative release of thorium and good quality of sample for α-spectrometry were determined. Thorium yield in fluoride precipitation step was (98 ± 9)%. Total yield of thorium in the whole method, defined by thorium-234 was (98 ± 11)%. Decontamination factor of uranium for samples containing up to 500 g/l of uranium according to the methods was ~ 10^2 ÷ 10^3. Thus, the proposed method make it possible to perform a thorium preconcentration from large volumes of natural waters, providing its quantitative extraction and good separation from uranium. This methom can be recommended for determination of total analytical concentration of thorium and its isotopic composition by alpha-spectrometry.
Speaker: Anna Paliga (ФГАОУ ВПО «УрФУ имени первого Президента России Б.Н.Ельцина»)
• 185
Development of automated system for continuous remote control of radioactivity emitted by nuclear power plants
Speaker: Prof. Vladimir Kolotov (Vernadsky Institute of Geochemistry and Analytical Chemistry)
• 186
Distribution of 137Cs, 238,239+240Pu and 241Am in soils and lakes from the Central Spitsbergen
Soils play an important role in accumulation of airborne radionuclides. Plutonium isotopes released by nuclear weapons testing are still present in the environment, especially in soils. There are several sources of radioactive contamination in the European sector of the Arctic. The most substantial include global weapons fallout, fallout from nuclear weapons testing near Novaya Zemlya and from Chernobyl accident, and discharges from the nuclear reprocessing plants Sellafield (UK) and La Hague (France). The aim of this study was to investigate activity concentrations, activity ratios and inventories of 137Cs, 238Pu, 239+240Pu and 241Am in 8 soil profiles and 3 bottom sediment profiles from tundra lakes of Petuniabucta coast (Central Spitsbergen). The loose and poorly developed soils were collected from raised marine terraces covered with sandy-gravel sediments (PET1, PET2, PET3) and from coarse-grained screes (PET4, PET6, PET8). The Ebbadalen tundra lakes (PEL1, 2, 3) occupy shallow depressions underlain by mineral soil or thin peat in permafrost terrain. Results obtained in this study show differences in activities of artificial radionuclides among the investigated profiles. The highest activities of 137Cs, 238Pu, 239+240Pu and 241Am observed in profile PET4, reached 123±11 Bq/kg, 0.13±0.04 Bq/kg, 3.82±0.31 Bq/kg and 1.2±0.1 Bq/kg, respectively. Artificial radionuclides in most of the tundra soils were concentrated in the upper 4 cm but in one profile (PET5) maximum activity concentrations each radionuclide was observed at 10 cm depth. The deeper occurence of radionuclides in profile PET5 can be explained by occasional accumulation of aluvial deposits in that site. Location of activity maxima points to accumulation of 10 cm thick deposits during last 50 years. The activity ratios provide important information on the origin of radioactivity in soils, as they can be used to distinguish between global (stratospheric) and regional (tropospheric) sources of these radionuclides. Isotopic analysis of plutonium reveals provenance of this radionuclide, for example whether the plutonium burdens are associated with bomb fallout or are derived from other sources. The 238Pu/239+240Pu activity ratios varied from 0.02 ± 0.01 to 0.07 ± 0.02, suggesting global fallout as the dominant source of Pu (0.03-0.05). The 239+240Pu/137Cs activity ratios varied from 0.02 ± 0.01 to 0.09 ± 0.02 and exceeded published global fallout ratio for Svalbard of 0.05. The 241Am/239+240Pu activity ratios ranged between 0.32 ± 0.04 and 1.24 ± 0.13 and exceeded the global fallout ratio for Svalbard of 0.37 due to the relatively higher geochemical mobility of Pu vs. Am and/or ingrowth of Am from the decay of 241Pu. The 137Cs inventories in each profile were lower than the deposition fluxes (2.2 kBq/m2) reported for Svalbard. The 239+240Pu inventories varied between 20.1 ± 1.6 to 50.3 ± 5.0 Bq/m2 and exceeded values of 239+240Pu 14 - 26 Bq/m2 from atmospheric weapon testing. This study was supported by the Foundation for Polish Science PARENT-BRIDGE Programme co-financed by the EU European Regional Development Fund.
Speaker: Dr Edyta Łokas (H.Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences)
• 187
Effect of high ionic strengths on U(VI) retention in montmorillonite
Argillaceous rock and clay minerals have properties that make them very suitable for nuclear waste storage. They are practically impermeable and have high sorption capacities. North German clay deposits feature pore waters of particularly high ionic strengths, ranging from 1.8 mol/l to 3.3 mol/l. in the depths relevant for nuclear waste repositories.[1] To enable an informed decision about the long term safety of nuclear waste disposal, the effect of high ionic strengths on radionuclide retention needs to be taken into account. This work focuses on the uranium retention on montmorillonite (as model clay) in sodium and calcium chloride brines. These conditions are based on the Konrad mine that serves as reference site. There, montmorillonite is a major component. The ground water at a depth of about 480 m has sodium and calcium chloride as main components with an ionic strength of around 2.9 mol/l, and a pH between 5.75 and 6.85.[1] The effect of ionic strength on uranium sorption on montmorillonite is very small. A true ionic strength effect, which is a decrease of sorption with ionic strength, can solely be observed below pH 6 and only up to an ionic strength of 2 mol/l sodium chloride. In calcium chloride, there are effects that show a positive correlation between sorption and ionic strength in the alkaline pH range but these can be explained with secondary phase formation rather than true ionic strength effects. In the presence of carbon dioxide, U(VI) sorption decreases in the alkaline pH range regardless of electrolyte due to the formation of uranyl carbonate species. In the absence of carbon dioxide, U(VI) sorption at alkaline pH remains almost as high as the value at the sorption maximum. In general, the sorption maxima in both sodium and calcium chloride lie in the pH range of natural groundwaters in North German clay formations. Relative uranium uptake at the sorption maxima exceeds 99% for both electrolytes. Desorption experiments show that uranium sorption on montmorillonite in sodium chloride is largely reversible except for very high ionic strengths. In calcium chloride, on the other hand, reversibility depends less on ionic strength and more on pH.[2] Further results that will be presented concern uranium sorption in a mixed electrolyte that is modelled on the naturally occurring ground waters of the Konrad site. [1] Brewitz, W. (1982) Eignungsprüfung der Schachtanlage Konrad für die Endlagerung radioaktiver Abfälle. Gesellschaft für Strahlen- und Umweltforschung. [2] Zehlike, L. (2013) Durchführung von Sorptions- und Desorptionsversuchen von Uran(VI) an Montmorillonit, Bachelor thesis, TU Dresden.
Speaker: Ms Katharina Fritsch (Helmholtz-Zentrum Dresden-Rossendorf)
• 188
Examination of 238Pu, 239,240Pu and 137Cs radionuclide diffusion in soils and lake bottom sediments
Speaker: Mr Sarunas Buivydas (State Research Institute Center for Physical Sciences and Technology)
• 189
Exploration of radon-rich waters in crystalline terrains by gamma method in spite of radioactive disequilibrium
Speakers: Ms Lenka Hrušková (Charles University in Prague), Dr Viktor Goliáš (Charles University in Prague)
• 190
Extraction of rare earth elements from the natural and man-made raw by using supercritical carbon dioxide
In connection with the development of modern high-tech industries and changing market conditions in the last few years have seen a growing interest in rare-earth elements (REE). This necessitates the creation of new technologies for processing of mineral raw materials, as well as various industrial wastes and secondary resources. Virtually all fields of REE are part of complex ores, incorporating a wide range of components. In this context a crucial role in the development of deposits, processing of ores and other sources play an extraction and sorption methods are widely used for the extraction, separation and purification of individual REE. In this paper proposed the use of supercritical fluid extraction method for the isolation and separation of REE, uranium and thorium in the processing of mineral raw materials and industrial waste such as monazite concentrate and phosphogypsum. On the example of organophosphorus reagents such as TBP, CMPO, TOPO, and nitrogen-containing ligands DMDOGEMA and TODGA, as well as TBP-HNO3 adduct we studied the possibility of sorption of REE by the previously synthesized solid phase extractants, based on carbon nanotubes and polystyrene Taunit media. There was a fundamental possibility of separation of REE, uranium and thorium, the above extractants and their allocation to individual phases using supercritical carbon dioxide. A scheme for the processing of monazite concentrate and phosphogypsum.
Speaker: Dr Maxim Samsonov (Vernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academy of Sciences)
• 191
First Shrinkage Parameters of Slovak Bentonites Considered for Engineered Barriers in the Geological Repository for Radioactive Waste and Spent Nuclear Fuel
Speaker: Mr Adrian Krajnak (Comenius University in Bratislava, Faculty of Natural Sciences)
• 192
Humic acid as a sorbent modifier: humic acid induced synergetic sorption behavior of Prussian blue
Recent investigations show that sorption properties of solids in natural or synthetic humic acid (HA) solutions strongly depend on the ability of HA to form complexes with ions of sorbate and to interact with the surface of solids. In general, both factors are negative for the sorption technologies due to the known dramatic diminution of sorption processes in HA solutions. We found that industrially produced samples of Fe(II) cyanoferrate(II) (Prussian blue, PB) drastically change their sorption behavior in HA aqueous solutions in comparison with inorganic electrolyte solutions. Numerous experimental data showed that the revealed synergetic sorption of the couple “PB – HA” may be connected with two groups of factors: firstly, an effect of partial HA complex formation by cations in HA-solution which suppresses the known stereoselective sorption properties of d-metals cyanoferrates(II), and secondly, the growth of sorption affinity of some HA complexes of p-, d- and f-metal cations toward PB in the conditions when HA macromolecules don not interact with PB surface due to the same sign of electrostatic charge of interacting particles. In this presentation we show the results of investigation of the system “PB – HA” and discuss the reasons of the revealed enhancement of the sorption affinity of PB toward HA-complexes of ions of I-VI groups of D.I. Mendeleev Periodic System in the framework of the problem of chemical and radiochemical protection of the environment.
Speaker: Prof. Victor Remez (Ecsorb, the Compamy)
• 193
Immobilization of radionuclides into thermal insulation waste
Large amounts of low-density thermal insulation mineral wool waste contaminated by radionuclides arise from NPP operation. Melting of this waste reduces its volume by more than 10 times. Mineral fibers begin to lose their elastic properties at 440 оС and to soften at 700 оС. The minimum process temperature for molten fiber formation is ~ 1500 оС. Experiments were performed on mineral wool mats with specific activity of Cs-137(4.0-8.8)×108 Bq/kg. The experiments employed an industrial induction furnace as a waste melter. The melter was a graphite crucible with an opening provided at the bottom, through which the formed melt flowed down by drops into a receiving container. During the experiment, the melt discharge rate was from 1.8 to 2.2 kg/h, the melt temperature was 1350-1370 оС, and the rate of power consumption was 8.3 kW×h/kg. The solid-aerosol carry-over was not larger than 0.5 % and volatile loss of Cs-137 was only 2.8 % from the melting process. To reduce the mineral wool melting temperature from 1350-1370 оС to 1170-1190 0С, a low-melting fluxing agent, namely FeO (at least 10 wt. %), was used. The true density of the “frozen” mineral wool melt without addition of fluxing material was 2.7 g/cm3 and with addition of 10 % CaF2 the density increased to 2.8-2.9 g/cm3. Additional experiments were performed with crushed mineral wool incorporated into Portland cement modified by Cambrian clay as a sorption agent. The crushed wool was admixed to cement slurry with water-to-cement ratio of 0.7 and claycement ratio of 0.1. The density of produced cement compounds was about 1.8 g/cm3. Measurement of Cs-137 leaching from the thermal insulation waste forms has shown that addition of a fluxing agent to melt increases (almost by an order of magnitude) the radiocesium leach rate from the conditioned waste. But in any case this leach rate is of 10-7 g/cm2×day order after 150 days of the experiment. For comparison, Russia’s regulatory maximum value for Cs-137 leach rate from vitrified high-level waste is 1×10-7 g/cm2×day. For low- and intermediate-level wastes stored in standard concrete facilities, the acceptable rate of radiocesium leaching after 150 storage days is not higher than 1×10-3 g/cm2×day. Cemented thermal insulation waste forms with addition of clay comply with this requirement (the leach rate is ~1.0×10-4 g/cm2×day after 150 days).
Speaker: Prof. Vitaly Epimakhov (Nikolaevich)
• 194
Interlaboratory comparison on the determination of radionuclides in water, food and soil conducted by the National Atomic Energy Agency (NAEA), Poland
Proficiency tests (PT) on the determination of radionuclides in food and environmental samples have been organized by the National Atomic Energy Agency (NAEA), Poland, since 2004. The activity of the following radionuclides: 241Am, 137Cs, 3H, 239Pu, 226Ra and 90Sr were determined in water, food and soil. The PTs have been conducted by the Institute of Nuclear Chemistry and Technology (INCT), Warsaw, Poland and procedure adopted by the INCT is presented in the paper. The test materials: water, milk powder, wheat flour and soil, were prepared by spiking blank materials with standard solution of the radionuclide of interest. The activity concentrations were calculated and associated uncertainties were evaluated before sending the test materials to the laboratories. The results provided by the participants were statistically evaluated by means of z and zeta scores as well as using the International Atomic Energy Agency (IAEA) criteria for trueness and precision. Observed trends and some benefits for the participants have been presented.
Speakers: Ms Agata Oszczak (Institute of Nuclear Chemistry and Technology), Dr Leon Fuks (Institute of Nuclear Chemistry and Technology)
• 195
Isotopic Analysis As an Indicator of the Groundwater Stability
Natural radionuclides can be very good indicators of all hydrological and biogeochemical phenomena occurring in the water environment. Typical uses of environmental isotopes include the identification of source of water and solutes, determination of water flow paths, assessment of nutrients within the ecosystem, water budget. A few elements exhibit variations in their isotopic composition, resulting from radioactive decay its precursors present in the geological formations. These isotopic ratio variations can be used as natural fingerprint of rock – water interaction and applied in weathering and hydrology studies. In this work activity ratio of uranium and radium isotopes (234U/238U, 228Ra/226Ra), as well as of the stable strontium isotopic ratio (87Sr/86Sr) were determined in selected thermal groundwater, ground and surface water samples from central Poland. Uranium isotopes after co-precipitation with hydrated manganese dioxide were separated from other natural radionuclides by extraction chromatography resin (Dowex 1x8). The activity concentrations were determined by using α spectrometry with PIPS detector (Canberra). 228Ra was determined by gamma spectrometry after co-precipitation with MnO2, whereas 226Ra was determined by liquid scintillation counting. Strontium isotopic ratio after separation from other element by extraction chromatography resin (Dowex 50Wx8) was determined by thermal ionization mass spectrometry (TIMS). The average isotopic ratio for different type of water sample from Poddebice and Uniejow was shown in the Table 1. Table 1 Activity and isotopic ratio in different type water. location water type 234U/238U 228Ra/226Ra 87Sr/86Sr Poddebice thermal groundwater 0,923±0,020 1,64±0,35 0,708492±0,000014 deep well water 1,115±0,063 1,23±0,71 0,709454±0,000130 river water 1,027±0,116 2,67±1,14 0,709718±0,000466 Uniejow thermal groundwater 0,744±0,094 0,641±0,043 0,708441±0,000002 river water 1,232±0,161 1,95±0,49 0,709256±0,000059 The observed differences in these ratios confirms that the uranium, radium and strontium isotopic ratio can be useful indicator for determination of stability of the underground water reservoirs.
Speaker: Dr Magdalena Długosz-Lisiecka (Technical University of Lodz, Faculty of Chemistry)
• 196
Mitigating the environmental impact of high salt liquid radwaste concentrates incorporated into cement packages
Speaker: Dr Vitaly Epimakhov (Nikolaevich)
• 197
Mobility of radioactive cesium in soils originated from the Fukushima Daiichi nuclear disaster; Application of extraction experiments
Speaker: Dr Yoshikazu Kikawada (Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University)
• 198
Mobilization of radionuclides and heavy metals from mill tailings in a northern boreal environment
Speaker: Ms Hanna Tuovinen (University of Helsinki, Laboratory of Radiochemistry)
• 199
Monitoring of Radioactive Contamination of Polish Surface Waters in 2012-2013*
Speaker: Ms AGNIESZKA FULARA (CENTRAL LABORATORY FOR RADIOLOGICAL PROTECTION)
• 200
Natural radionuclide as a tracer in groundwater-surface water interactions at the artificial recharge system
Determining the relationship between surface water and groundwater systems is critical to understanding hydrogeological systems, protecting riverine ecosystems, and managing water resources. Due to its high activities in groundwater, the radionuclide 222Rn is a sensitive natural tracer to detect and quantify groundwater. In this study 222Rn and stable isotope were used as a tracer in groundwater and river water interaction. The short half-life(3.8 days) and chemically inert properties of radon make it a powerful and potentially useful tracer of hydrological processes at the fast interface interaction between surface and sub-surface water bodies. Study area is pilot artificial groundwater recharge system near Nakdong river in Korea. Rn-222 and stable isotope were used natural tracer to understand surface water recharge effect. Artificial recharge system was consist of four input and one pumping well. Rn-222 and stable isotope samples were collected during recharge operation time. For one day recharge operation period, Rn-222 concentration was decreased at the observation well groundwater. OBS-1 and 5 were decrease about 35 % due to surface water dilution effect but OBS-6 was 4 time increased due to surround groundwater input effect. The stable isotopes were similar trend with radon concentration but OBS-4 sample was different with other samples. This means different groundwater was introduced during recharge operation time. To understand surface water-groundwater interaction, 14 days artificial recharge experiment was performed and groundwater samples were collected during the operation time. This long-term experiment result showed radon concentration was not varied at the OBS-1 and 2. However, OBS-3 was increased and OBS-4 was decreased with time and about 200 hours passed radon concentration was not varied severely.
Speaker: Dr Yoon Yeol Yoon (Korea Institute of Geoscience and Mineral Resources)
• 201
Naturally-occurring radioactivity in table wines
Table wines are part of the Mediterranean diet and a common component of the adults’ diet in many countries. Wines are produced from vineyards grown in soils of different types from loam soils to granitic soils and in regions with different natural radioactivity levels. Twenty table wines, red and white, from large producers in several regions of Portugal, encompassing uranium provinces, were analyzed for naturally occurring radionuclides including uranium isotopes, 226Ra, 210Po and 232Th. Four other bottled table wines imported from Spain, France, USA, and Chile were analyzed for comparison. Uranium activity concentrations (238U) in Portuguese wines ranged from 1.1 to 12.9 mBq/L, 226Ra ranged from 2.0 to 22.0 mBq/L and 210Po from 14.8 to 74.4 mq/L. These ranges are nearly comparable to the activity concentration ranges determined in imported wines. Concentration of radionuclides in Portuguese wines were assessed by regions and it was observed that 238U concentrations were in average slighter higher only in wines from granitic regions of the Centre-North than from sedimentary regions of the south of the country. Radium (226Ra) concentrations in the wines were generally higher (by a factor of 2) than those of uranium, reflecting enhanced root uptake of radium from soils into grapes, such as commonly observed in many agriculture products. Polonium (210Po) concentrations in wines were in the average higher (by a factor of 4) than 226Ra concentrations, indicating that most 210Po in wine was probably from atmospheric depositions on vines and grapes rather than from root uptake. Radionuclide concentrations in table wines are comparable to concentrations of the same radionuclides in drinking water, and the radioactivity exposure through this ingestion pathway is minor. Results suggest that natural radionuclide levels in wine from several continents and latitudes may be very similar.
Speaker: Dr João M. Oliveira (Instituto Superior Técnico/LPSR)
• 202
Neutrino Emission and the Safety of Nuclear Objects
Speaker: Mr George Ryazantsev (B.)
• 203
New insights into uranyl interaction with proteins
Given uranium toxicity, comprehension of uranyl interaction with biological material of human relevance is of utmost importance, from the whole body scale to the molecular level. At the molecular level, uranium interaction with proteins has attracted a lot of attention, in particular the blood serum proteins Human Serum Albumin (HSA) and Transferrin, which are likely to transport uranyl in the body and therefore to play a key role in its toxicity (1-5). It is well known that uranyl undergoes complex speciation at physiological pH, and can form complexes with serum small molecules such as carbonates, making the study of such systems rather intricate. The interaction of uranyl with a protein was studied, while taking into account all known uranyl species that could exist at physiological pH. Bovine Serum Albumin (BSA) is well known to bind several metals, and shares similarities with Human Serum Albumin, which makes it a good candidate for a uranyl-binding protein model. The interaction was followed by means of UV-Visible spectroscopy, circular dichroism and fluorescence measurements (static and time-resolved). Strong fluorescence quenching of the protein was observed upon uranyl addition. Addition of BSA to a uranyl solution also resulted in uranyl fluorescence quenching. The data obtained were treated using speciation software CHEAQS and a fitting program developed in the laboratory. On this experimental basis, the model proposed, involving two successive complexations of several uranyl moieties is in very good agreement with the experimental data. Our results allowed determination of the number of uranyl moieties complexed by the protein, as well as the corresponding equilibrium constants. Further experiments are in progress to determine the functional groups of the proteins involved in the complexation. The experimental protocol and data analysis could be applied to virtually any protein containing enough fluorescent residues to measure the quenching induced by uranyl addition. Further studies with HSA are in progress, and first results will be also presented and compared to the literature (2,6). References 1 Michon J. et al., J. Fluoresc., 2010, 20, 581-590 2 Montavon G. et al., J. Inorg Biochem, 2009, 103, 1609-1616 3 Vidaud C. et al., Biochemistry, 2007, 46, 2215-2226 4 Benavides-Garcia M.G., Balasubramanian K., Chem. Res. Toxicol. 2009, 22, 1613-1621 5 Hémadi et al., J. Phys. Chem. B, 2011, 115, 4206-4215 6 Duff M.R.et al., Angewandte Int. Ed., 2006, 45, 137-139
Speaker: Dr Quentin Raffy (IPHC - Strasbourg University)
• 204
Pb-210 and Po-210 in Some Medicinal Plants
Speaker: Dr Natalia Gomzina (N.P.Bekhtereva Institute of the Human Brain, Russian Academy of Sciences (IHB RAS), St. Petersburg, Russia)
• 205
Peculiarities of plutonium isotopic ratio determination by elemental mass spectrometry
Inductively coupled plasma high resolution mass spectrometry (ICP-MS) is widely used technique for 240Pu/239Pu isotopic analysis tool which leads to use plutonium isotopic composition to assess the artificial radionuclide source in the environment fast and accurately. ICP-MS measurements usually are performed in low resolution mode (m/dm=300) to enhance and maximize plutonium signal sensivity. In this measurement mode various interferences emerge from sample solutions and are likely to overlap plutonium isotopic signal. To study occurring interferences soil samples were used. They were prepared by using ion exchange and extraction chromatography separation techniques. It was determined that 238U1H+ interfering ion must be taken into the account if 238U+ signal in the sample exceeds 1E5 cps. However, to take into the account 238U1H+1H+ interference is not necessary. Besides, it is strongly not recommended to use hydrochloric acid as a final stabilizing matrix as serious 204Pb35Cl+ interferences occur on 239 a.m.u mass. For final stabilizing matrix five solutions were tested and it was found that the best one to use is ultrapure nitric acid as it creates the lowest background signal on 239 and 240 a.m.u masses.
Speaker: Mr Andrius Puzas (Center for Physical Sciences and Technology, LITHUANIA)
• 206
Polonium (210Po), lead (210Pb) and uranium (234U, 235U, 238U) contamination of environment surrounding phosphogypsum waste heap in Wiślinka (northern Poland).
Speaker: Mr Grzegorz Olszewski (University of Gdansk, Faculty of Chemistry, Institute of Environmental Protection and Human Health, Chair of Environmental Chemistry and Radiochemistry, Laboratory of Analytical and Environmental Radiochemistry)
• 207
Polonium - 210 and Lead - 210 in urine samples of Warsaw residents
Speaker: Dr Lidia Rosiak (Central Laboratory for Radiological Protection)
• 208
Polonium 210Po in edible mushrooms collected in northern Poland
The main aim project was 210Po determination in caps and stems of mushrooms from Leccinum pseudoscabrum, Leccinum aurantiacum, Leccinum vulpinum, Leccinum duriusculum and Leccinum quercinum collected in Pomorskie, northern Poland. Mushrooms are organisms which contain a lot of water (75-90%). Mushrooms absorb heavy metals such as mercury, chrome, cadmium and radionuclides: e.g. polonium, uranium, plutonium from the environment (soil, air). Our studies have shown that the radionuclides are included not only in green plants, but also in mushrooms. Radioactive elements are taken either from the soil, through the mycelium or directly from the entire surface gathered in the fruiting bodies. As a result of the Chernobyl accident radioactive contamination of the environment has grown considerably. Many European countries were contaminated with significant amounts of radioactive elements. In our research natural polonium 210Po were determined. 210Po is characterized by high radiotoxicity and its main sources in the environment are water, food, urban pollution and the Chernobyl accident. The average 210Po concentration in caps and stem mushroom ranged from 0.85±0.09 mBq∙g-1 in Leccinum quercinum stem to 10.77±0.47 mBq∙g-1 in Leccinum pseudoscarbum cap. Analysis of 210Po concentrations in mushrooms showed its higher values in caps than stem. This means the main source of 210Po is wet and dry atmospheric fallout. The studies showed interspecies differences among all analyzed speciec and Leccinum pseudoscarbum (10.15 mBq∙g-1) as well as Leccinum aurantiacum (11.83 mBq∙g-1 ) accumulated more polonium than Leccinum vulpinum (2.22 mBq∙g-1), Leccinum duriusculum (3.65 mBq∙g-1 ) and Leccinum quercinum (3.57 mBq∙g-1).
Speaker: Ms Karolina Szymanska (Faculty of Chemistry, University of Gdansk)
• 209
Porosity of inorganic ion-exchangers and their sorption selectivity towards the ions of heavy metals and radionuclides.
The report presents data about the new method of synthesis of inorganic ion-exchangers in continuous mode of sol-gel process, which provides the possibility of obtaining the spherically granulated hydrogels and xerogels of highly porous oxides, silicates and phosphates of polyvalent metals. The basis of the process – the reactions of templating competitive interactions between Fe and Al salts and the basic components in the reaction mixture, namely, with Ti and Zr salts, as well as phosphoric and silicic acids and sodium, potassium, ammonium hydroxides etc. [1,2 ]. Using the washing procedure of gel spherical particles (d = 0,2 ~ 1,2 mm ) by water with different pH values and organic solvents, it is possible, after drying, to obtain the inorganic ion-exchangers with bimodal nanoporosity, in particular, with transport ultramicro- and meso-pores and with the specific surface area values around 200- 600mg/g It was shown that due to the factors of structural compliance (between the size of ultramicropores and diameter of sorbed ions) and also complex formation with functional and hydroxyl groups in the matrix of ion-exchangers, the selective sorption of cations of d- metals and trace amount of radionuclides 137Cs, 90Sr, 239Pu, 241Am, and uranium is carried out from solutions with complex composition. It was also found that in case of the uranium sorption from the model solutions of uranyl acetate on the highly porous titanium phosphates is occured the formation of a separate phase of uranyl phosphate in mesopores at pH range ~ 5-7, wherein the sorption equilibrium is reached only during ~ 3000 hours. In the report is also presented data that demonstrate the effect of various factors on the sorption selectivity of radionuclides Cs and Sr, and also uranium and transuranic elements by powdered forms of ion-exchangers on the basis of amorphous titanium silicates. It was found that this inorganic ion-exchanger has, in some way, the properties of universal sorbent, capable to selective sorption of the most long-lived radionuclides from solutions with complex composition. Finally, it was shown that the combined use of some inorganic coagulants, based on titanium compounds, and the inorganic ion-exchangers investigated in this project enables to purify, almost completely, the liquid radioactive waste of destroyed 4th block of the Chernobyl nuclear power plant from the entire spectrum of radionuclides. In the report is also presented the field data of our investigations at the Chernobyl nuclear power plant. 1. V.Strelko. Method of Completing for Sol-Gel Processing of Sorbents and Catalysts in Aqueous Solutions of Inorganic Salts. Focusing on Materials for Pollution Control, Water Purification, and Soil Remediation, Edts. P.Innocenzi, Yu. L.Zub, V.G.Kessler. Sprsnger. 2008, p.p. 227-251. 2. V.V.Strelko. New Sol-Gel Processes in the Synthesis of Inorganic Sorbents and Exchangers Based on Nanoporous Oxides and Phosphates on Polyvalent Metals. J. Sol-Gel Sci. Technol. 2013, (on line).
Speaker: Prof. Volodymyr Strelko (Institute for Sorption and Problems of Endoecology of National Academy of Sciences of Ukraine)
• 210
Pu(V) and Pu(IV) oxidation state distribution in natural clay
Environmental behavior of Pu isotopes can be strongly affected by oxidation–reduction reactions which can result in changes of their speciation, solubility and transport. Pu(V) and Pu(IV) sorption to three well characterized samples from the industrial exploitation site Šaltiškiai in North Lithuania was used to study their sorption kinetics and oxidation state distribution in natural clay systems. The composition of clay mineral coatings and their leaching during the sequential extraction procedures were investigated by means of the Mössbauer spectroscopy and X-ray diffraction. Pu (IV) and Pu(V) were added to achieve their initial concentration of 3•10-10 mol•L-1. Solids were separated by centrifugation at 6000xg after a desired time. Pu activity concentrations were measured by alpha spectrometry. The oxidation state distribution analysis was performed using thenoyltrifluoroacetone (TTA), bis(2-ethylhexyl) hydrogen phosphate (HEDHP) and 1,3-diphenyl-1,3-propanedione (DBM) solvent extraction as well as Pu(III, IV), Pu(V), Pu(VI), Pu(IV) and Pu(IV polymeric) species were separated. In the natural clay systems the Pu oxidation state distribution analysis in the liquid-phase indicated a comparatively high content (up to 75%) of Pu(III/IV) at pH~5, while polymeric species of Pu(IV) were found to be the dominant species at higher pH. Pu oxidation states in the solid-phase were determined after the desorption step using 3 mol•L-1 HCl, and Pu(III,IV), Pu(V) and Pu(VI) as well as Pu(IV) at pH~0 were analyzed in parallel. The content of Pu(III) was calculated from mass balance analysis. The obtained results showed that Pu(V) was mainly reduced to Pu(IV), and a small portion of Pu(III) found in the system was explained as a result of reduction by iron-bearing minerals such as montmorillonite and siderite present in the Triassic clay samples. Experimental data obtained from the laboratory and field observation were used in modeling. The kinetic curves were evaluated by fitting the experimental data with six different types of kinetic models derived for the following six control processes: mass transfer (DM), film diffusion (FD), diffusion in the inert layer (ID), diffusion in the reacted layer (RLD), chemical reaction (CR) and gel diffusion (GD). Financial support provided by FP7 RECOSY, grant No 212287, the Agency for Science, Innovation and Technology of the Republic of Lithuania (contract No. TAP-36/2010), the Research council of Lithuania (contract No. TAP-54/2010) as well as by the Ministry of Education of the Czech Republic (contract No. MSM 6840770020) is acknowledged.
Speaker: Dr Galina Lujaniene (SRI Center for Physical Sciences and Technology, Savanorių ave 231, Vilnius, LT-02300, Lithuania)
• 211
Radioactivity and heavy metal concentrations and assessment of hazard indices in sediments from Zhushan bay at Taihu Lake, China
Surface sediment cores from the Zhushan bay of Taihu lake in China were collected. In this study, the concentration of eleven heavy mentals(Al, Co, Cr, Cu, Mn, Ni, Ti, V, Zn, Pb, Cs) and the radioactivity of two radionuclides (210Pb and 137Cs) were investigated. The mean concentration of Cr, Cu, Ti, Pb indicated is slightly higher than the background values, and the rest doesn’t exceed the background value. Compared with the levels in the Environment Quanlity Standard for soils of China (EQSS), the mean values of main heavy metals, such as Pb, Zn and Cr, is located level 1 of soil quanlity, which showed the concentration of these elements is ordinary in the sediment. while the concentration for Cu is located level 2 which indicated there is minor enrichment for Cu. The situation was confirmed by the enrichment factor (EF) of heavy metals showing the samilar result. In terms of radioactivity concentration for 210Pb and 137Cs, the mean 139.9 Bq/kg for 210Pb and 21.3Bq/kg for 137Cs were more lower than the limited value 260 Bq/kg and 120 Bq/kg according to the Standard soil of quality assessment for Exibition site (SSQAE) of China. The study result implied that the lacustrine sediment can be retired to the farmland or used to be construction materials in the ecological enginnering of dredging process.
Speaker: Mr Mingli Zhang (School of Geography Science, Nanjing Normal University; Center for Nuclear Technology, Technical university of Denmark, Risø Campus)
• 212
Radioactivity in water from uranium mining regions