Dr
Štefan Palágyi
(Nuclear Research Institute Řež plc)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
In the framework of the development of remediation scenario of underground areas affected by chemical mining of uranium in the locality of Stráž pod Ralskem a complex geochemical and transport model is generated, which comprises interaction of rocks and groundwater affected by acid leaching. The chemical remediation processes also require the knowledge of the properties of the affected rocks....
Dr
Mihály Molnár
(MTA ATOMKI)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
The aim of this work was the investigation of the effect of nuclear fuel rods to the composition of the dissolved gas in the cooling water of the cooling ponds of Paks Nuclear Power Plant (Paks NPP).
In normal cases after three-year usage in the reactor the spent fuel elements are stored in cooling ponds for years before delivering out from the reactor area. In April of 2003 with the failure...
Mr
Martin Straka
(Nuclear Research Institute Řež, plc)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
The presented work is focused on research of basic electrochemical properties of several actinides and lanthanides representing the fissile material and fission products in suitable molten fluoride melt. The general framework of this work is to study the electrochemical behaviour of systems relevant for possible future use in the Generation IV reactor concepts.
Results of cyclic...
Dr
Matteo Mazzuccato
(European Commission, Joint Research Centre, Ispra Site Directorate, Italy)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
A future goal for the reprocessing of spent nuclear fuel is the transmutation of long-lived minor actinides, such as americium and curium, into short-lived isotopes by means of neutron irradiation. In order to develope an effective transmutation process, it is necessary to separate the trivalent minor actinides, An(III), from the trivalent lanthanides, Ln(III) by means of two subsequent...
Dr
P.N. PATHAK
(BARC, MUMBAI, INDIA)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Tributyl phosphate (TBP) has been the work horse of Nuclear Fuel Reprocessing Technologists for more than five decades. However, based on five decades of experience on spent fuel reprocessing, certain problems have also been identified with the use of TBP as extractant. Prominent amongst them are: (a) high aqueous solubility, (b) poor radiation stability and interference of degradation...
David Dobrev
(Nuclear Research Institute Rez)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
The knowledge of chemical conditions, especially of redox potential, inside waste packages with radioactive wastes is important for determination of radionuclides speciation and their leaching rate after failure of waste packages. Conditions inside waste packages will be determined primarily by the reactions of thermodynamically unstable iron with groundwater penetrating into waste packages...
Mr
Pavel Selucký
(Ústav jaderného výzkumu Řež)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Abstract
The nuclear fuel reprocessing isues an important problem in respect to handling of the family of actinides which represent the main source of radiotoxity during long-term storage. The separation of long lived radionuclides from liquid radioactive waste enables these hazardous elements to be either conditioned more safely in specific matrices, or destroyed by transmutation. Thus,...
Prof.
Valentin Avramenko
(Institute of Chemistry FEBRAS)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Here we discuss preparation of a new type of colloid-stable nanosized sorbents based on functionalized latex particles, which can be directly applied for decontamination of liquid and solid radioactive wastes or used for construction of fibrous or mesoporous composite sorption materials. Carboxylic latex (siloxane-acrylate and polystyrene-acrylate) functionalization is performed via...
134.
Immobilisation of cesium and divalent metals into single-phase stuffed tridymite-based ceramics
Mr
Andrey Zaripov
(FSUE Mayak PA, Ozyorsk, Russia)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
The mixed phosphates with high caesium concentration of the compositions CsMePO4 (Me − divalent metal with a tetrahedral coordination) adopting a stuffed β-SiO2 tridymite structure are studied as perspective materials for a 137Cs γ-radiation sources to be used in medic applications. For the purpose of 137Cs source production from commercial radiocaesium liquid wastes (nitrate caesium solutions...
petr polivka
(czech chemical society)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
A large number of processes will influence performance of deep geological repository of radioactive wastes until the activity of radionuclides decay to a negligible level. One of the very important processes is generation of gases, and particularly of hydrogen, which will be formed primarily by anaerobic corrosion of metals and by radiolysis of water. High pressure formed in the vicinity of...
Dr
Olga Shmidt
(Khlopin Radium Institute RPA)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Cementation provided by mixing of concentrated radioactive waste (RAW) and cement is the most common procedure for immobilization of medium- and low-level radioactive salt-containing waste of radiochemical industry. However, low degree of inclusion of solidified waste in concrete (especially from concentrated salt-containing solutions owing to deterioration of the concrete properties) and...
Prof.
Viacheslav Radchenko
(JSC "State Scientific Center - Research Institute of Atomic Reactors")
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Long-lived nuclide 99Tc is accumulated as a fission product in 1-3 kg/t quantities in fuel of nuclear power plants. Transmutation of technetium by the action of neutrons is the most cardinal method for its neutralization and disposal; this leads to the production of artificial stable 100Ru, 101Ru. Several technetium targets have been irradiated at SSC RIAR. Metal technetium in the form of...
Prof.
Dr.Mr.ASHRAF ELSAYED MOHAMED MOHAMED
(World Institute of nuclear secuirity"Austria')
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Pyrochemical separations , involving molten salt and metal media , by liquid/liquid extraction or electrorefining are studies for nuclear defense and civil applications. The electrochemical properties of plutonium have been studied in molten salt-ternary eutectic mixture NaCI-KCI-BaCI2, equimolar mixture NACI-KCI and pure CaCI2 - and in liquid gallium at 1073 k. These processes concern...
Mr
Tamás Nagy
(Isotoptech Co. Ltd., Debrecen, Hungary)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
In the Püspökszilágy Radioactive Waste Treatment and Disposal Facility, Hungary being in operation since 1976 many works began to solve the storage of the non-power plant radioactive waste of Hungary to fulfil the increasing safety demands. In the framework of this procedure the exhumation of 66 pieces of reinforced concrete near-surface vaults with the size of 70-140 m3 each (called vault...
Mr
Petr Kovařík
(Nuclear Research Institute Rez plc.)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
A molten salt oxidation (MSO) process is being studied for the safe and
effective destruction of organic components of radioactive waste. The
work involves a laboratory-scale molten salt oxidation system where solid
or liquid waste is injected into a bed of molten carbonate salt in the
presence of an oxidizing gas. The relatively simple MSO process
completely destroys organic compounds,...
Dr
Galina Lujaniene
(Institute of Physics)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Recently growing concern about contamination of the environment with radioactive and non-radioactive pollutants resulted in intensive studies related to the development of new technologies for separation of radionuclides from liquid waste. These new technologies should be based on highly selective materials (e.g., crystalline titanium silicates) which are hard to decompose over a wide range of...
Ms
Kateřina Videnská
(Institute of Chemical Technology)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Radionuclides of 99Tc and 129I belong among the fission products of spent nuclear fuel and are the largest contributions with long-term nuclear waste. The high proportion of risk from these radionuclides is due to their large inventories in many types of waste, long half-lives, and the perception that they are highly mobile in the environment and therefore play potentially large role in...
Dr
Samer Amayri
(Institute of Nuclear Chemistry, Johannes Gutenberg-Universität Mainz)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
The sorption of Np on clay such as Opalinus clay (OPA) is one of many important processes that affect the migration and retardation of Np in the geosphere. Clay formations are under consideration in several European countries as a potential host rock for high-level radioactive waste repositories [1]. We studied the sorption of Np(V) onto OPA (from Mont Terri, Switzerland) both by batch...
Dr
Monica Felipe-Sotelo
(Loughborough University)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
The current concept for the disposal of intermediate- and low-level waste in the United Kingdom involves the emplacement of the grouted waste confined in stainless steel canisters in a cementitious repository deep underground [1]. The NRVB (Nirex reference vault backfill) is a cementitious material specially formulated for this purpose, composed by a mixture of ordinary Portland cement (OPC),...
Dr
Nicholas Evans
(Loughborough University)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Within the nuclear industry, waste management and disposal issues, both within the plants themselves and in the surrounding areas, are complex and problematic. This is partially a result of many decades of discharges within the storage site. A major problem is in determining the nature and distribution of contamination within the environment, be this on site in surrounding host rock, or...
Dr
Vejsada Jan
(Nuclear Research Institute)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Sorption of radionuclides on bentonite represents in most of deep geological repository (DGR) concepts important process retarding radionuclide migration into geosphere. In the Czech Republic, DGR concept takes local bentonite into account as material for both buffer and backfill. The candidate bentonite comes from the Rokle deposit (NW Bohemia) and represents complex mixture of...
Mrs
Yulia Korneyko
(V. G. Khlopin Radium Institute)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Technetium-99 is beta-active long-lived artificial radionuclide (half-life more than 200,000 years). Because of its long-life, high content in spent nuclear fuel, high ability to oxidize under aerobic conditions as ТсО4- Tc is one of the most dangerous radionuclides. Development of chemically durable host-phase for Tc disposal is important goal of research.
There are no natural minerals of...
Dr
Mihály Molnár
(MTA ATOMKI)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
To obtain reliable estimates of the quantities and rates of the gas production in L/ILW a series of measurements was carried in the last seven years in Hungary. Drums filled with selected original L/ILW coming form the light water PWR type Paks Nuclear Power Plant (Hungary) were placed into special hermetic containers and its gas generation was measured carefully. Headspace gas analysis of...
Dr
Albert Aloy
(Khlopin Radium Institute)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Vitrification of radioactive wastes and high temperature synthesis of glass and ceramics for ionizing radiation sources, containing Cs-137, is accompanied by discharge of its vapours. The off-gas contaminated by Cs-137 must be cleaned up using different trapping systems.
In general two methods of Cs-137 vapour catching are possible, differing both in process character (nature) and realization...
Mr
Kamil Vavřinec Mareš
(Czech Republic)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
This project focuses on studying properties of extraction-chromathographic material prepared by embedding of tributylphosphate (TBP) into the matrix of polyakrylonitrile (PAN). After elementary characterization of the prepared materials, the kinetics of uranium extraction from 3 mol·L-1 HNO3 was examined. The influence of nitrates and nitric acid concentration on the values of weight...
Dr
Monica Felipe-Sotelo
(Loughborough University)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
One of the illustrative disposal concepts considered by the NDA- RWMD (Nuclear Decommissioning Authority – Radioactive Waste Management Directorate) for the disposal of intermediate-level wastes and some low-level wastes is that of grouted waste packages surrounded by a cementitious backfill. The potential use of superplasticisers to improve flow properties of waste encapsulation grouts offers...
Prof.
Wangsuo Wu
(Lanzhou University)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Adsorption of Cs+ to Beishan soil (BS) as function of pH, foreign ions, temperatures, contact time and humic substances was studied in detail under ambient conditions using batch techniques. The results suggested that the adsorption of Cs+ was strongly dependent on ionic strength, whereas nearly independent of pH values, and the values of Kd were 1388.78 mL/g...
Anumaija Leskinen
(Loughborough University)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
Natural organic matter (NOM) is being characterised and investigated for use as a remediation material in various applications.
Two readily available environmental materials are being tested:
Material A: 68% by weight of the material is organic including 19% humic acid, 28% fulvic acid and 21% humin. 32% of the material is inorganic, containing 23% iron.
Material B: 57% by weight of the...
Mr
Tamás Nagy
(Isotoptech Co. Ltd., Debrecen, Hungary)
22/04/2010, 12:00
Chemistry of Nuclear Fuel Cycle, Radiochemical Problems in Nuclear Waste Management
Poster
The Radioactive Waste Treatment and Disposal Facility, Püspökszilágy, Hungary is in operation since 1976. Low and intermediate level radioactive wastes originating from different industrial, medical, educational and scientific areas are treated here. At the beginning of its operation the facility had to fulfil only safety requirements but not regulations pertaining to the form and the quality...