PGAA (Prompt Gamma Activation Analysis) is an established nuclear analytical technique for the non-destructive determination of elemental and isotopic compositions. The neutron activation analysis research group in KAERI (Korea Atomic Energy Research Institute) has been developing a fake gold bar detection method using a PGAA. However, a real experiment to verify the detection method was not...
In this study, a rapid method using single column separation and fusion for determination of the uranium in environmental samples (e.g., soil, sediment, air particulate, etc.) is presented. Various certified reference materials (CRM) of soil and sediment were used to evaluate the accuracy and precision for the developed method. Samples were rapidly digested using an alkali fusion (LiBO2)...
Most hazardous elements contribute significantly to contamination of agricultural soils. Their content in the soil increases above background level due to anthropogenic influences as industry ballast and transportation and energy production, especially in the surface layer of the humus horizon. Accumulation of hazardous elements in the soil has a significant ecological impact on the speed of...
Rapid bioassay methods have been mainly proposed for the sequential measurements of actinides in human blood, bone marrow and urine. The method involves sample treatment using microwave digestion techniques followed by direct measurement of digested products using powder scintillator and alkaline solution as a replacement for traditional liquid scintillation cocktail. The selected group of...
Chromatographic techniques are applicable in a wide spectrum of scientific fields and are also advantageous in different kinds of interdisciplinary research. By these techniques we are able to analyse compound composition of unknown samples, purity of solvents but they can be applied also for the preparation of analytes with subsequent analysis of stable or radioactive isotopes. Based on...
Graphene oxide (GO) has two important characteristics: (I) it can be produced by cost-effective chemical methods, and (II) it is highly hydrophilic and can form stable aqueous colloids to facilitate the assembly of macroscopic structures by simple and cheap solution processes. In this work, the possibility of using of GO and GO modified by Mn and Fe have been examined. In order to find...
Building of the first AMS laboratory in the Czech Republic has recently been started in co-operation of the Nuclear Physics Institute of the Czech Academy of Sciences (NPI), the Faculty of Nuclear Sciences and Physical Engineering of the Czech Technical University in Prague and the Institute of Archaeology in Prague of the Czech Academy of Sciences. The laboratory will be located on the...
Radioactive Fe-55 is generated by neutron activation of stable iron and, therefore, it can be found in materials from nuclear power plant, which should be decommissioned. It decays by electron capture and emits x-ray of 5.9 keV (24.5% probability). Because of the low energy of emitted ray, the attenuation effect is large and it occurs already in the sample itself, therefore it is the most...
The current concept of handling low-level liquid radioactive waste (LRW) consists of development of technological schemes providing efficient and cheap LRW treatment. In addition, such technologies ought to lead to compacting of radioactive waste in combination with long-term, reliable and safe isolation from the biosphere. Unfortunately, some types of waste from the nuclear industry still...
A rapid method to determine plutonium in water is to separate it on microfiltration polymer membranes impregnated with antimony, zirconium, and manganese oxides or zirconium, titanium and other phosphates, having the highest efficiency for adsorption of plutonium. In addition, ballast salts are removed. A method was developed for determining the total activity of alpha emitters with...
Rapid determination of selected gross alpha and beta emitters in environmental matrices by solid-state scintillation technique is discussed. This method is based on sample treatment using microwave reactor and direct measurement of digested products using powder scintillator and alkaline solution as a substitute for traditional liquid scintillation cocktail. The selected group of radionuclides...
To identify and characterize illicit trafficking and smuggling nuclear material, information obtained from analysis of unknown samples are important and helpful for authorities (Law Enforcement) to give fast and appropriate response actions.
In the framework of studies and collaboration with safeguard networks, our laboratory is able to carry out the characterization of nuclear material using...
The content of thorium (Th) on the earth's crust is three to four times higher than the uranium, so the idea of using thorium as the main component of nuclear fuel is currently developing.
In recent years High Energy Resolution Fluorescence Detected (HERFD) and Resonant Inelastic X-ray Scattering (RIXS) were shown to be a highly valuable tool for investigation of the electronic structure of...
This study proposes the approach to remove the contribution of Rn-222 from the measured gamma-ray spectra, which achieved from a HPGe spectrometry. Several scenarios of flushing the central detector volume with nitrogen gas to actively remove the radon isotopes were simulated to evaluate the effect of Radon on the low-background gamma-ray spectra. To quantify the gamma background a set-up was...
The analysis of wipe samples is of great importance in nuclear safeguards. Total reflection X ray fluorescence spectrometry as a trace nondestructive analysis method can preliminarily analyze the wipe samples and provide references for screening, making it easier to make follow-up analysis plans. The method of determining uranium in wiped samples by full reflection X ray fluorescence...
The Blanka tunnel complex, a part of the Prague City Ring Road, is with a length of about 5.5 km the longest road tunnel in the Czech Republic and the longest city tunnel in Europe. Designed to relieve the historic center of Prague from heavy traffic, it connects the area west of Prague Castle with the Trója district in the northeast. The construction of Blanka started in 2007. Initially due...
Neutron activation analysis (NAA) can be conveniently used to measure microgram amounts of arsenic. However, in biological materials major elements such as bromine, chlorine, and sodium can produce high activities resulting in poorer detection limits for arsenic. The 559.1-keV photopeak of 76As (half-life = 25.9 h) is particularly interfered with by the 554.3-keV photopeak of 82Br (35.3 h) and...
Ex-core monitoring of irradiated fuel rod leakage using general-purpose assembly of fault detection is based on identification of 85Kr release from leaking irradiated fuel assemblies. The sensitivity of this method is defined by minimum volume activity of this nuclide that is authentically measured in air mixture of leak-tight circulation circuit (LTCC) via the radiation monitoring system...
Radionuclide 131I is used as a reference nuclide for monitoring of gas-aerosol emissions. Under the normal operating modes, 131I radionuclide release does not exceed admissible values, however, during conduction of some activities in the plant premises it can exceed admissible levels that can be potentially dangerous for personnel because of high toxicity of the iodine. In case of accident,...
An instrumental neutron activation analysis (INAA) method was developed for the determination of some major, minor and trace elements in 93 different Canadian food samples. One portion of the sample was irradiated for 1 min at a neutron flux of 4 x 1011 cm-2 s-1 in the Kyoto University Reactor (KUR), Japan. Gamma-ray spectra of the irradiated samples were recorded after 1.5 min decay for 5 min...
For the analysis natural radionuclides, gamma spectroscopy, alpha spectroscopy and liquid scintillation counter(LSC) were used. Among them, LSC was widely used because it can be applied alpha, beta and gamma emitting nuclides. But some low activity nuclides are not analyzed because most of the LSC used 20 mL vial. Therefore, some radionuclide, such as H-3, are needed concentration. To improve...
One of the crucial advantages of the PIXE (Particle Induced X-ray Emission) technique is its non-destructive approach to the sample treatment during the analytical process. Rare and precious environmental samples can be analysed in order to evaluate the concentration of individual elements presented in the specimen. Composition of various samples and material has been investigated using PIXE...
In this article the properties of four new luminophores, from the group of bifluorenes and other substances with multiple aromatic rings, were measured and studied for possible use in liquid scintillation, namely 1-phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline, 2,2´,7,7´-tetrakis(N,N-diphenyl-amino)-9,9´-spirobifluorene, 2-(4-biphenylyl)-6-phenylbenzoxazole and 9,9´-bifluorenyl. The...
The prompt gamma activation imaging (PGAI) using the neutron beam has been used in archeology and cultural heritage researches to obtain the two- or three-dimensional elemental distribution of the volumetric sample. To measure the high-energy prompt gammas emitted by the neutron induced nuclear interactions with the sample, a simple measurement system, which consists of an HPGe detector, a...
A new supramolecular composition containing a clozoborane salt UO2 [ B10H9S(C18H39)]2 ,
polyvinyl chloride (PVC) as a matrix and tris (2-ethylhexyl) phosphate. The membranes of various compositions with different ratios of membrane components were investigated.
The membrane with the best electroanalytical characteristics has the following composition:
Сs B10H9S(C18H37)2 : 1 – 3 % (mass),
tris...
The need for determining the U-235/U-238 isotopic ratio in a naturally occurring radioactive material (NORM) is increasing to warn a leakage of uranium into the environment. During the process of seeking a non-destructive method of analyzing natural matrices for uranium isotopes U-235 and U-238, a major source of uncertainty was found to be the gamma-ray intensities. Ra-226 and U-235 are...
Recently, the CENTA laboratory was established at Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava. The laboratory comprises the system for production of various ion beams from solid and gaseous samples, the energy and mass separation and the 3 MV tandem accelerator, that is used for acceleration of the ions up to tens of MeV. The beams can be used for several...
In recent years, radionuclide 236U has become a significant analytical tool. Due to it's mostly anthropogenic origin, the main purpose of it's determination resides in tracing of human nuclear activities, though it can be used for studying plenty of natural phenomena like natural fission reactors or deep sea currents as well. Since natural samples usually contain only a trace amount...
Radiocarbon dating is an exact dating method and its pioneer was the team of Professor F.W.Libby in the 1950s. This is the most significant and most commonly used 14C determination application. Within the carbon cycle in nature, 14 C is generated in the upper part of the atmosphere by the interaction of 14N with cosmic radiation 14N (n, p) 14C. Radiocarbon is relatively quickly oxidized to...
Low-level concentrations of primordial and cosmogenic radionuclides were determined in recently fallen chondrites and in meteorites from Mars and the Moon. The radionuclide measurements showed a wide range of concentrations of $^{22}Na$, $^{26}Al$, $^{46}Sc$, $^{54}Mn$ and $^{57}Co$. The absence of the neutron product ($^{60}Co$) in some of the meteorites indicates that their pre-atmospheric...
Elemental and isotopic characterization of spent nuclear fuel is of crucial importance in nuclear reactor facilities for various purposes, including the management of spent nuclear fuel [1]. Characterization of spent nuclear fuel samples requires highly sensitive and precise mass spectrometric techniques, such as sector-field inductively coupled plasma-mass spectrometry (SF-ICP-MS) and...
The cold neutron beam guide of HANARO research reactor has a length of about 100 m and the cold neutron has a velocity of about 300 m / s. At this time, the cold neutrons are affected by gravity for about 0.333 seconds. In the Hanaro study, there is no history of measuring the influence of gravity and it is not reflected in the design. In this study, neutron beam images of the neutron energy...
This paper deals with the study of 1-phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline, 2,2´,7,7´-tetrakis(N,N-diphenyl-amino)-9,9´-spirobifluorene, 2-(4-biphenylyl)-6-phenylbenzoxazole and 9,9´-bifluorenyl as possible replacements of the existing and most widely used luminophore (2.5-diphenyloxazole (PPO)) in contemporary scintillators. The study was focused on the determination of emission...
The study of nuclear forensics can effectively deal with nuclear security incidents and potential nuclear terrorist threats, and prevent radioactive crimes or terrorist attacks. Through the analysis of the nuclear material of nuclear fuel cycle different stage, the initial source of nuclear material and the whole production process could be revealed. Due to the different geological conditions...
Thorium and Uranium are representative elements of actinide metal that have naturally radioactivity and widely distributed in the environment [1,2]. Thorium is used as a material for producing nuclear fuel, and ThO2 is often employed as a catalyst. Also, thorium is applied in high-quality lenses and high-tem-perature ceramics, and the alloys of thorium are frequently used in air craft...
Insights into the manner in which tritium is associated and retained in metals can be gained by studying total tritium and its progressive loss with incremental heating from 20-900°C. A range of metals from two nuclear sites and one non-nuclear site has been investigated for their tritium content and associated thermal desorption profiles. These metals have had different exposure histories to...
The Microtron MT 25 is a cyclic electron accelerator with a Kapitza type resonator. The accelerator is located in a laboratory belonging to the Nuclear Physics Institute of the CAS. The Microtron MT25 serves as a source of relativistic electrons (primary electron beam), secondary photon beams (bremsstrahlung) and neutrons from nuclear reactions. Photon beams are frequently used for...
