検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

JAEA-TDB-RN in 2020; Update of JAEA's thermodynamic database for solubility and speciation of radionuclides for performance assessment of geological disposal of high-level and TRU wastes

2020年版JAEA核種TDB; 高レベルおよびTRU廃棄物地層処分の性能評価に用いる放射性核種の溶解挙動評価のためのJAEA熱力学データベースの更新

北村 暁

Kitamura, Akira

高レベル放射性廃棄物およびTRU廃棄物地層処分の性能評価に用いるJAEA熱力学データベース(JAEA-TDB)のうち、放射性核種溶解挙動評価部分(JAEA-TDB-RN)について、地球化学計算部分(JAEA-TDB-GC)を包含する形で更新を実施した。今回の更新では、従来の選定値が標準状態における反応の平衡定数(対数値log$$_{10}$$$$K^{circ}$$)だけであったのに対して、ギブズ標準自由エネルギー変化($$Delta_{rm f}$$$$G^{circ}_{rm m}$$),標準モルエンタルピー変化($$Delta_{rm f}$$$$H^{circ}_{rm m}$$),標準モルエントロピー($$S^{circ}_{rm m}$$),比熱容量($$C$$$$^{circ}$$$$_{rm p,m}$$),反応の自由エネルギー変化($$Delta_{rm f}$$$$G^{circ}_{rm m}$$),反応のエンタルピー変化($$Delta_{rm r}$$$$H^{circ}_{rm m}$$)および反応のエントロピー変化($$Delta_{rm r}$$$$S^{circ}_{rm m}$$)を追加することで、大幅な選定値の拡充を行うとともに、298.15K以外の温度における溶解挙動評価が実施できるよう整備が行われた。また、経済協力開発機構原子力機関(OECD/NEA)がレビュー、選定および集約した鉄についての最新の熱力学データを取り込んだ。さらに、JAEA-TDB-GCと選定値の内部整合性を図るために、多くの反応のlog$$_{10}$$$$K^{circ}$$について再計算を実施した。更新したJAEA-TDBを有効活用するために、PHREEQCおよびGeochemist's Workbenchといった地球化学計算コード用フォーマットを提供した。

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 ($$Delta_{rm f}$$$$G^{circ}_{rm m}$$), change in standard enthalpy change of formation ($$Delta$$$$H$$$$^{circ}$$$$_{rm m}$$), standard molar entropy ($$S^{circ}$$$$_{rm m}$$) and, heat capacity ($$C^{circ}_{rm p}$$), change in standard Gibbs free energy of reaction ($$Delta_{rm r}G^{circ}$$$$_{rm m}$$), change in standard enthalpy change of reaction ($$Delta$$$$_{rm r}$$$$H$$$$^{circ}$$$$_{rm m}$$) and standard entropy change of reaction ($$Delta_{rm r}S^{circ}_{rm m}$$) as well as logarithm of equilibrium constant (log$$_{10}$$$$K^{circ}$$) 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$$_{10}$$$$K^{circ}$$ 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.

Access

:

- Accesses

InCites™

:

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.