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Kitamura, Akira
JAEA-Data/Code 2020-020, 164 Pages, 2021/03
Part of JAEA's Thermodynamic Database (JAEA-TDB) for solubility and speciation of radionuclides (JAEA-TDB-RN) for performance assessment of geological disposal of high-level radioactive and TRU wastes has been updated with subsuming the database for geochemical calculations (JAEA-TDB-GC). This report has focused to update JAEA-TDB-RN after selecting change in standard Gibbs free energy of formation (), change in standard enthalpy change of formation (), standard molar entropy () and, heat capacity (), change in standard Gibbs free energy of reaction (), change in standard enthalpy change of reaction () and standard entropy change of reaction () as well as logarithm of equilibrium constant (log) at standard state. The extent of selection of these thermodynamic data enables to evaluate solubility and speciation of radionuclides at temperatures other than 298.15 K. Furthermore, the latest thermodynamic data for iron which have been critically reviewed, selected and compiled by the Nuclear Energy Agency within Organisation for Economic Co-operation and Development (OECD/NEA) have been accepted. Most of previously selected log have been refined to confirm internal consistency with JAEA-TDB-GC. Text files of the updated JAEA-TDB have been provided for geochemical calculation programs of PHREEQC and Geochemist's Workbench.
Kitamura, Akira; Yoshida, Yasushi*; Goto, Takahiro*; Shibutani, Sanae*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 27(2), p.58 - 71, 2020/12
Evaluation and estimation of solubility values are required for a performance assessment of geological disposal of high-level radioactive and TRU wastes. Selection of solubility-limiting solid phases (SSPs) that control the solubility of radionuclides is necessary for the evaluation and estimation of solubility values. The authors have developed a methodology for selection of the SSP through a calculation of saturation indices (SIs) using thermodynamic database to show a transparent procedure for the selection. Literature survey should be performed to confirm decision of the SSP from candidate SSPs which generally have larger SIs from realistic point of view for precipitation and solubility control. The authors have selected the SSPs for the elements of interest for the latest Japanese performance assessment in bentonite and cement porewaters after grouping various water compositions.
Miwa, Shuhei; Nakajima, Kunihisa; Miyahara, Naoya; Nishioka, Shunichiro; Suzuki, Eriko; Horiguchi, Naoki; Liu, J.; Miradji, F.; Imoto, Jumpei; Afiqa, B. M.; et al.
Mechanical Engineering Journal (Internet), 7(3), p.19-00537_1 - 19-00537_11, 2020/06
We constructed the fission product (FP) chemistry database named ECUME for LWR severe accident. This version of ECUME is equipped with dataset of the chemical reactions and their kinetics constants for the reactions of cesium(Cs)-iodine(I)-boron(B)-molybdenum(Mo)-oxygen(O)-hydrogen(H) system in gas phase, the elemental model for the high temperature chemical reaction of Cs with stainless steel applied as the structural material in a reactor, and thermodynamic data for CsBO vapor species and solids of CsSiO and CsFeSiO for these chemical reactions. The ECUME will provide estimation of Cs distribution due to the evaluation of effects of interaction with BWR control material B and stainless steel on Cs behavior in the Fukushima Daiichi Nuclear Power Station.
Kitamura, Akira
Nihon Genshiryoku Gakkai-Shi ATOMO, 62(1), p.23 - 28, 2020/01
Thermodynamic databases (TDBs) for performance assessment of geological disposal of high-level waste and TRU waste have been developed to predict solubility and speciation of radionuclides in groundwater in some countries including Japan. The present manuscript briefly describes current status of development of the TDB organized by the Nuclear Energy Agency within the Organisation of Economic Co-operation and Development (OECD/NEA) and the TDBs in some countries including Japan.
Kitamura, Akira
JAEA-Data/Code 2018-018, 103 Pages, 2019/03
The latest available thermodynamic data were critically reviewed and the selected values were included into the JAEA-TDB for performance assessment of geological disposal of high-level radioactive and TRU wastes. This critical review specifically addressed thermodynamic data for (1) a zirconium-hydroxide system through comparison of thermodynamic data selected by the Nuclear Energy Agency within the Organisation for Economic Co-operation and Development (OECD/NEA), (2) complexation of metal ions with isosaccharinic acid based on the latest review papers. Furthermore, the author performed (3) tentative selection of thermodynamic data on ternary complexes among alkaline-earth metal, uranyl and carbonate ions, and (4) integration with the latest version of JAEA's thermodynamic database for geochemical calculations. The internal consistency of the selected data was checked by the author. Text files of the updated and integrated thermodynamic database have been prepared for geochemical calculation programs of PHREEQC and Geochemist's Workbench.