Journal of Radioanalytical and Nuclear Chemistry

In 2015-2017, we measured activity concentration of radiocesium in the western subtropical gyre of the North Pacific Ocean and revealed the time evolution of radiocesium derived from the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident between 2011 and 2017. The FNPP1-derived radiocesium deposited on the area south of the Kuroshio/Kuroshio Extension Currents in March 2011 was transported southward and westward through subsurface layers due to subduction of the subtropical mode water. In 2014, the radiocesium in the subsurface layers returned to the north and circulated within the Kuroshio recirculation area...

Nuclear energy has been a part of the energy mix in many countries for decades. Today in principle all power producing reactors use the same techniqe. Either PWR or BWR fuelled with oxide fuels. This choice of fuel is not self evident and today there are suggestions to change to fuels which may be safer and more economical and also used in e.g. Gen IV nuclear power systems. One such fuel type is the nitrides. The nitrides have a better thermal conductivity than the oxides and a similar melting point and are thus have larger safety margins to melting during operation...

Since plants live on inorganic elements, absorbing ions from roots and transferring them to each tissue in a plant is an essential activity. However, little is known about the movement of the elements or water in plant tissue. Though fluorescent imaging is now overwhelmingly used at the microscopic level in biology, especially to visualize chemicals or organelles in a cell, radioisotope imaging has become one of the important methods for human imaging in the medical field. In the case of plant studies, however, real-time radioisotope imaging is little-known among plant researchers...

Distributions of radiocaesium (134 Cs and 137 Cs) derived from the Tokyo Electric Power Company (TEPCO) Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident in the North Pacific Ocean in the summer of 2012 were investigated. We have estimated the radiocaesium inventory in the surface layer using the optimal interpolation analysis and the subducted amount into the central mode water (CMW) by using vertical profiles of FNPP1-134 Cs and mass balance analysis as the first approach. The inventory of the 134 Cs in the surface layer in the North Pacific Ocean in August-December 2012 was estimated at 5...

The paper describes the age (production date) determination of uranium reference materials using the 231 Pa/235 U ratio. Direct addition of 237 Np in secular equilibrium with its 233 Pa daughter was chosen instead of the regular milking of 237 Np to avoid possible loss of Pa. Sample preparation consists of a fast, one-step procedure. The developed method using ICP-MS for the measurement of 231 Pa is more precise than alpha spectrometry and is applicable for freshly produced low-enriched uranium materials. The measured ages are in good agreement with the reported production dates, thus the 231 Pa/235 U chronometer can be applied for validation of 230 Th/234 U in nuclear forensics and safeguards...

Long range transport of radiocaesium derived from local fallout occurred early 1950s, global fallout which occurred mainly late 1950s and early 1960s and the Fukushima accident occurred in 2011 were investigated and presented for ocean surface in the Pacific Ocean. HAM database and its update were used in this study to present whole history of radioccaesium transport in surface layer in the interested region. Since both the main local/global fallout regions and injection of radiocaesium by Fukushima accident occurred in the western North Pacific and constrain of surface current systems which governed surface transport processes were subtropical gyre and subarctic gyre, radiocaesium transport in surface water in the mid latitude was characterized as rapid eastward transport along Kuroshio and Kuroshio extension...

The aim of the article was to verify the hypothesis concerning the diversification of plutonium sources in the natural environment of Antarctica. Plutonium activity and atom ratios were analyzed in two groups of biological samples: terrestrial and marine. Both isotopic ratios in the terrestrial set were consistent with global radioactive fallout ratios. The average activity ratio in the marine ecosystem was lower than global radioactive fallout. At the same time mass ratio values in this group turned out to be surprisingly varied...

The objective was to study changes in water-saturated biodiesel irradiated by electron beam and to analyse them considering the influence of absorbed dose. Based on obtained results it can be concluded that irradiation did not affect ester groups in FAME molecules, but strongly influenced on double bonds. Total ester content decreased linearly with the increase in absorbed dose, causing FAME not to meet the requirement of PN-EN 14214 concerning the ester content (96.5 wt%). Therefore, the use of ionizing radiation to improve biodiesel properties is unlikely, but it is worth to consider electron beam sterilisation of this biofuel...

It is well known that monitoring of radioactivity released from nuclear medicine departments is necessary to ensure the radiological safety of patients and personnel. Unfortunately, equipment for air sampling is often expensive, loud and is not suitable to use in hospitals. Our goal was to find cheap and simple system for passive monitoring of 131 I activity concentration in the air of nuclear medicine departments. Medical activated charcoal tablets were used, because charcoal is excellent material for 131 I trapping and tablets are readily available...

Using the real-time radioisotope imaging system (RRIS), we present the carbon dioxide gas fixation process of a soybean plant applying the 14 C-labeled gas. When 14 CO2 gas was supplied to the selected mature leaf, the fixed carbon, photosynthate, was transferred and accumulated to the younger leaves preferentially within 24 h. When 14 CO2 gas was supplied to the younger leaves, fixed carbon was hardly moved. In the case of the pods, fixed 14 CO2 gas in the leaf was preferentially transferred to the closest pod...

Related to the recent nuclear release of radioactive ruthenium isotopes in fall 2017, we analyzed air filters from Vienna for irregularities in the (stable) elemental composition of particulate matter from this period. Methods were SEM/EDXS and INAA. For comparison, a reference filter from 2007 and blank filters were used. The chemical fingerprint encompassed 28 elements. The results show no indication for a considerable change in the elemental composition of the suspended matter. For example, no anomalies in the abundance of platinum group elements were found...

The Sr and Cs adsorption capacities of LithoFill™, LithoGran™ and a competing clinoptilolite containing zeolite product were investigated by radioanalytical methods (85 Sr and 134 Cs gamma spectroscopy). The dependence of adsorption and adsorption rate on physical factors including temperature, available ions and time were assessed. In addition, the reversibility of adsorption under high ionic strength conditions was also examined. In general, cesium is more strongly adsorbed than strontium, adsorption yields are generally independent of temperature (from room temperature to 65 °C) and adsorption is relatively rapid (identical results for 2 or 5 day adsorption times)...

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans the testing of nuclear explosive devices underground, in the atmosphere and underwater. Two main technologies, radionuclide and seismo-acoustic monitoring, are deployed in the International Monitoring System used for the verification of the CTBT. Medical isotope production from fission-based processes is the dominant contributor to a worldwide background of radioxenon. This background can make the discrimination of nuclear tests from legitimate nuclear activities very challenging...

N -Methyl carbamoylimidazole is a safe and practical alternative to methyl isocyanate for carbamoylation reactions. We have developed a new chemical route for its synthesis from methyl iodide and applied this to the synthesis of N -[11 C]methyl carbamoylimidazole as a new [11 C]synthon to radiolabel biomolecules for PET imaging research. N -[11 C]methyl carbamoylimidazole was prepared from [11 C]methyl iodide in 70-74% radiochemical yield (decay corrected) and can be used in situ for further reaction without purification...

The most advanced methodology for the pyroprocessing of spent nuclear fuel is the electrorefining of uranium metal in LiCl-KCl eutectic, in which uranium is solubilized as U(III). The production of U(III) in LiCl-KCl eutectic by the chlorination of uranium metal using BiCl3 has been performed for research purposes. In this work, this reaction was studied in-situ by visual observation, electronic absorption spectroscopy and electrochemistry at 450 °C. The most likely mechanism has been determined to involve the initial direct oxidation of uranium metal by Bi(III) to U(IV)...

This review compiles the combined chemical and enzymatic synthesis of aromatic l-amino acids (l-phenylalanine, l-tyrosine, l-DOPA, l-tryptophan, and their derivatives and precursors) specifically labeled with carbon and hydrogen isotopes, which were elaborated in our research group by the past 20 years. These compounds could be then employed to characterize the mechanisms of enzymatic reactions via kinetic and solvent isotope effects methods.

As an emergency action during the Fukushima accident, seawater was used to maintain cooling. To evaluate the effect of the salt on fission-products, sodium chloride, and tellurium were heated together using different ratios in different atmospheres (inert or oxidizing) using thermogravimetric analysis. The experiment under inert conditions showed no indication of interaction. However, under oxidizing conditions an interaction for all samples was observed that prevented an otherwise observed mass increase of the tellurium reference...

Redox interaction of reduced technetium forms and technetium(VII) with neptunium(III), neptunium(IV) and neptunium(VI) have been investigated using electrochemical and spectroscopic (Vis-NIR) techniques. The neptunium species most stable in 4 M H2 SO4 , i.e. Np(IV) ions, do not reduce Tc(VII) in contrast to Np(VI) ions which oxidize Tc(IV) species to Tc(VII). The interaction of pertechnetates with Np(III) leads to formation of Tc(IV) species. The Vis-NIR measurements showed the generation of intermediate Tc(V) and Np(V) forms during the oxidation of Tc(IV) and competitive reduction of Np(VI)...

Gamma irradiation studies of (Mg0.905 Fe0.095 )2 SiO4 olivine were performed using X-ray fluorescence method, X-ray diffraction, Raman and Mössbauer spectroscopy. The absorbed doses were 300, 600 and 1000 Gy. Small irradiation doses cause an increase of lattice vibrations and small deformation of both M1 and M2 octahedron. The observed effect is similar to the results expose to high temperature. However, the small deformation takes place only in unit cell of Olivine's structure.

Proton-induced reaction (p,α) is one type of nuclear reaction analysis (NRA) suitable especially for light element quantification. In the case of lithium quantification presented in this work, accelerated protons with an energy about of 850 keV were used to induce the 7 Li(p,α)4 He reaction in standard reference and geological samples such as tourmaline and other Li-minerals. It is shown that this technique for lithium quantification allowed for measurement of concentrations down below one ppm. The possibility to relate the lithium content with the boron content in a single analysis was also demonstrated using tourmaline samples, both in absolute concentration and in lateral distribution...