Development of radionuclide migraton datasets of safety assessment for TRU waste disposal in Japan

我が国におけるTRU廃棄物処分の安全評価のための核種移行データセットの開発

三原 守弘  ; 佐々木 良一; 亀井 玄人 

Mihara, Morihiro; Sasaki, Ryoichi; Kamei, Gento

原子力機構と電気事業連合会が公表したTRU廃棄物処分研究開発第2次取りまとめにおける安全評価のための核種移行データセットを開発した。TRU廃棄物処分施設にはセメント系の充填材料やベントナイトの緩衝材の使用が検討されており、これらの長期的は変遷を考慮したデータセットを開発した。考慮したプロセスとしてセメント系材料の浸出,ベントナイトのカルシウム型化及び高アルカリ性による鉱物学的な変質である。

Japan Atomic Energy Agency and The Federation of Electric Power Companies of Japan have published the second progress report on research and development for TRU (long-lived) waste disposal in Japan. This report is important to promote the establishment of a regulatory framework and an implementation body for TRU waste disposal in Japan. A deep geological underground disposal with cementitious filler and bentonite buffer for a part of this waste was considered to isolate the waste from the biosphere over the long-term. In this safety assessment of the repository, radionuclides migration datasets were needed. The solubilities, diffusion coefficients and sorption coefficients of radionuclides for cementitious filler and compacted bentonite buffer are some of the important parameters. These datasets were developed considering the long-term chemical evolutions of engineered barriers and variation of ground water type under the reducing condition.