A thorough description of the reaction mechanisms, taking into account different possible spin states, offers insights into the gas-phase reaction of plutonium atoms with water. Two possible reactions (isomerization and dehydrogenation) are presented. These reactions are found to be exothermic, with the best thermochemical conditions observed for the dehydrogenation reaction at around 23.5 kcal mol(-1). The nature of the chemical-bonding evolution along the reaction pathways are investigated by employing various methods including electron localization function, atoms in molecules, and Mayer bond order. Total, partial, and overlap population density of state diagrams and analyses are also presented. Reaction rates at elevated temperatures (T=298-2 000 K) are calculated by using variational transition-state theory with one-dimensional tunneling effects. In dynamics simulations, only the dehydrogenation reaction is observed, and found to be in good agreement with experimental values.
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http://dx.doi.org/10.1002/cphc.201402327 | DOI Listing |
J Hazard Mater
January 2025
State Key Laboratory of Loess and Quaternary Geology, Xi'an AMS Center, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, PR China; Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Xi'an 710061, PR China. Electronic address:
Radiation risk through seafood consumption is a big public concern under the discharge of nuclear contaminated water. Plutonium is an important radionuclide in view of radiation risk due to its high radiological and chemical toxicity, as well as consistent presence in the environment. The distribution and level of plutonium isotopes (Pu, Pu) in marine biota collected along the coast of China in 2022-2023 were investigated.
View Article and Find Full Text PDFTalanta
January 2025
National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Chiba, Chiba, 263-8555, Japan; Department of Physics, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba, 274-8510, Japan.
Natural uranium isotopes have extremely long half-lives; therefore, analytical methods based on the number of atoms, such as X-ray fluorescence (XRF) analysis, are suitable for uranium detection. However, XRF measurements cannot be used to detect the major isotopes of americium when present in amounts barely detectable using radiation measurements, owing to their relatively short half-lives. Because of α-decay-induced internal conversion, where orbital electrons are emitted instead of γ-rays, these nuclides emit characteristic X-rays.
View Article and Find Full Text PDFAppl Radiat Isot
January 2025
China Institute of Atomic Energy, Beijing, 102413, China.
This paper presents a comprehensive and detailed analysis of the OECD-NEA MOX fuel benchmark based on different nuclear data libraries to investigate the reliability and accuracy of the Dragon5 lattice code developed by École Polytechnique de Montréal for the neutronic analysis of mixed uranium-plutonium oxide (MOX) fuel. The neutronics and burn-up calculations for rectangular pin and assembly geometries filled with different compositions of MOX fuel are computed. The performance of different nuclear data libraries is evaluated.
View Article and Find Full Text PDFJ Environ Radioact
December 2024
1 Kiowa Lane, White Rock, NM, 87547, USA.
Glass fragments (16 green glasses and 2 red glasses) were handpicked from crushed Trinitite. X-ray diffraction studies revealed that these samples were essentially pure glass with the exception of minor amounts (less than 4 wt%) of quartz (which acts as a diluent) in some samples. The concentrations of 45 elements in the Trinity glasses were determined using Instrumental Neutron Activation Analysis.
View Article and Find Full Text PDFChemosphere
November 2024
Department of Mass Spectrometry, Institute of Nuclear Physics Polish Academy of Sciences, Ul. Radzikowskiego 152, 31-342 Kraków, Poland.
Cryoconite, granule-shaped debris found on the surface of glaciers, is known for trapping substantial quantities of pollutants such as radioactive nuclides and heavy metals. This study investigates contamination levels, sources and spatial variability of natural and artificial radioisotopes in cryoconite from Mittivakkat Gletsjer in southeast Greenland by determining the activity and atomic ratios of selected radionuclides. The maximum activity concentrations of artificial radioisotopes were 1129 ± 34 Bq kg for Cs, 3.
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