次世代燃料サイクルのための高レベル廃液調整技術開発,12; 模擬残渣と硝酸の反応

Development of high-level liquid waste conditioning technology for advanced nuclear fuel cycle, 12; Reaction of simulated residue with nitric acid

宇佐見 剛*; 塚田 毅志*; 森田 泰治  

Usami, Tsuyoshi*; Tsukada, Takeshi*; Morita, Yasuji

次世代核燃料サイクルの再処理におけるガラス固化の負担を軽減するための高レベル廃液調整技術開発として、Mo, Pd, Ruの分離技術開発と不溶解残渣個別処理技術開発を行っている。不溶解残渣性状評価の一環として、不溶解残渣の硝酸への溶解挙動把握のため、不溶解残渣を模擬したRu, Rh, Pd, Mo, Reの5元素から成る合金を製造し、構成元素比と硝酸への溶解挙動の関係を調べた。試験の結果、PdとMoの濃度が高いほど溶解しやすくなる傾向が見られ、Pdを含まない合金は全く溶解しないことがわかった。逆にRuを除外した合金は短時間で溶解した。

Development of high-level liquid waste (HLW) conditioning technology for advanced nuclear fuel cycle was conducted for the purpose of the reduction of potential problems in the verification process for HLW. It includes development of separation technology for Mo, Pd and Ru from HLW and development of separate treatment of the insoluble residue. To evaluate characteristics of the insoluble residue, simulated residue of metal alloy composed of Ru, Rh, Pd, Mo and Re was dissolved with heated nitric acid. The results showed that higher concentration of Pd and Mo in the alloy makes the alloy easier to be dissolved. The alloy without Pd was hardly dissolved by nitric acid. On the other hand, the alloy without Ru was dissolved easily.