不溶解残渣の長期溶解挙動

Long-term dissolution behavior of insoluble residue

宇佐見 剛*; 塚田 毅志*; 森田 泰治  

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

再処理におけるガラス固化で問題となる不溶解残渣について、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の試験を行った。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結果、PdとMoの濃度が高いほど溶解しやすく、Ruの濃度が高いほど溶解しにくくなる傾向が見られた。

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.