(Invited) Pyrochemical Reprocessing of Used Nuclear Fuels

2019 ◽  
Vol 33 (7) ◽  
pp. 339-349 ◽  
Author(s):  
Tadafumi Koyama ◽  
Yoshiharu Sakamura ◽  
Masatoshi Iizuka
Keyword(s):  
Nuclear Fuels ◽  
Pyrochemical Reprocessing

scholarly journals Behaviour of Rare Earth Elements in Molten Salts in Relation to Pyrochemical Reprocessing of Spent Nuclear Fuels

2019 ◽  
Vol 3 (35) ◽  
pp. 493-502 ◽  
Author(s):  
Vladimir A. Volkovich ◽  
Boris D. D. Vasin ◽  
Trevor R. R. Griffiths ◽  
Ilya B. Polovov ◽  
Evgenii O. O. Medvedev ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Molten Salts ◽  
Nuclear Fuels ◽  
Pyrochemical Reprocessing

scholarly journals Thermochemical studies of advanced nuclear fuels and materials

2000 ◽  
Vol 72 (10) ◽  
pp. 1839-1849 ◽  
Author(s):  
Michio Yamawaki ◽  
Tadashi Inoue ◽  
Toru Ogawa
Keyword(s):  
Mass Spectrometry ◽  
High Temperature ◽  
Nuclear Material ◽  
Oxide Ceramics ◽  
Nuclear Fuels ◽  
Transuranium Elements ◽  
High Temperature Mass Spectrometry ◽  
Gas Reactions ◽  
Pyrochemical Reprocessing

Thermochemical analyses related with development of advanced nuclear fuels (i.e., metalic, nitride, and hydride fuels) with respect to the transmutation of transuranium elements and relevant pyrochemical reprocessing and fabrication processes, which have been carried out mainly in Japan, are summarized. In addition, application of atmosphere-controlled high-temperature mass spectrometry on solid-gas reactions, in particular on the prediction of gas-interacting behaviors of cesium and lithium on respective oxide ceramics, are delineated in relation to nuclear material-relevant researches.

Decontamination of Molten Salt Wastes for Pyrochemical Reprocessing of Nuclear Fuels

2013 ◽  
Vol 1518 ◽  
pp. 97-102 ◽  
Author(s):  
Martin C. Stennett ◽  
Matthew L. Hand ◽  
Neil C. Hyatt
Keyword(s):  
Molten Salt ◽  
Nuclear Energy ◽  
Reaction Medium ◽  
Fission Products ◽  
Chloride Salt ◽  
Nuclear Fuels ◽  
Alkali Chloride ◽  
Low Temperature Synthesis ◽  
Pyrochemical Reprocessing ◽  
Conventional Solid State Synthesis

ABSTRACTPyrochemical reprocessing of nuclear fuels, in which electrochemical separation of actinides and fission products is mediated by a molten alkali chloride salt (typically a LiCl-KCl eutectic) is of interest for future nuclear energy cycles. A key challenge in the management of pyrochemical reprocessing wastes is decontamination and recycling of the molten salt medium to remove entrained actinides and radioactive lanthanide fission products. Since pyrochlore oxides are promising candidates for the immobilisation of lanthanides and actinides, we sought to use the “problematic” molten salt to our advantage as a reaction medium for low temperature synthesis of titanate pyrochlores. Through control of reaction time and temperature, we demonstrated the synthesis of lanthanide pyrochlores at temperatures as low as 700 °C in 1 h, compared to 1350 °C in 36 h for conventional solid state synthesis. The importance of this study is in demonstrating the potential feasibility for decontamination of pyrochemical reprocessing wastes by simple addition of TiO2 to form lanthanide and actinide pyrochlores by rapid molten salt assisted reaction at moderate temperature.

Coupled Mass and Heat Transport Models for Nuclear Fuels using Thermodynamic Calculations

2018 ◽  
Author(s):  
Srdjan Simunovic ◽  
Jake W. Mcmurray ◽  
Theodore M. Besmann ◽  
Emily Moore ◽  
Markus H. A. Piro
Keyword(s):  
Heat Transport ◽  
Thermodynamic Calculations ◽  
Nuclear Fuels ◽  
Transport Models

Transportation: Fuel Energies

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Energy Density ◽  
Fossil Fuels ◽  
High Energy ◽  
Ease Of Use ◽  
Low Energy ◽  
High Energy Density ◽  
Nuclear Fuels ◽  
Liquid Hydrocarbons ◽  
Transportation Fuel ◽  
Journey Time

Transportation efficiency can be measured in terms of the energy needed to move a person or a tonne of freight over a given distance. For passengers, journey time is important, so an equally useful measure is the product of the energy used and the time taken for the journey. Transportation requires storage of energy. Rechargeable systems such as batteries have very low energy densities as compared to fossil fuels. The highest energy densities come from nuclear fuels, although, because of shielding requirements, these are not practical for most forms of transportation. Liquid hydrocarbons represent a nice compromise between high energy density and ease of use.

scholarly journals Nitrification Process in a Nuclear Wastewater with High Load of Nitrogen, Uranium and Organic Matter under ORP Controlled

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1607
Author(s):  
Mariano Venturini ◽  
Ariana Rossen ◽  
Patricia Silva Paulo
Keyword(s):  
Ammonia Oxidation ◽  
High Load ◽  
Nuclear Fuels ◽  
Monod Model ◽  
Nernst Equation ◽  
Nitrification Process ◽  
Real Wastewater ◽  
High Concentrations ◽  
Wastewater Samples ◽  
Very High

To produce nuclear fuels, it is necessary to convert uranium′s ore into UO2-ceramic grade, using several quantities of kerosene, methanol, nitric acid, ammonia, and, in low level, tributyl phosphate (TBP). Thus, the effluent generated by nuclear industries is one of the most toxic since it contains high concentrations of dangerous compounds. This paper explores biological parameters on real nuclear wastewater by the Monod model in an ORP controlled predicting the specific ammonia oxidation. Thermodynamic parameters were established using the Nernst equation to monitor Oxiders/Reductors relationship to obtain a correlation of these parameters to controlling and monitoring; that would allow technical operators to have better control of the nitrification process. The real nuclear effluent is formed by a mixture of two different lines of discharges, one composed of a high load of nitrogen, around 11,000 mg/L (N-NH4+-N-NO3−) and 600 mg/L Uranium, a second one, proceeds from uranium purification, containing TBP and COD that have to be removed. Bioprocesses were operated on real wastewater samples over 120 days under controlled ORP, as described by Nernst equations, which proved to be a robust tool to operate nitrification for larger periods with a very high load of nitrogen, uranium, and COD.

Diffusion of heavy elements in nuclear fuels: actinides in UO2

1965 ◽  
Vol 17 (3) ◽  
pp. 259-269 ◽  
Author(s):  
F. Schmitz ◽  
R. Lindner
Keyword(s):  
Heavy Elements ◽  
Nuclear Fuels
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