Electrochemical behavior of lanthanides and actinides on a liquid Ga electrode in molten chlorides melts

溶融塩化物中液体Ga電極におけるランタニドとアクチニドの電気化学的挙動

村上 毅*; 坂村 義治*; 飯塚 政利*; 野平 俊之*; 北脇 慎一 ; 小藤 博英  

Murakami, Tsuyoshi*; Sakamura, Yoshiharu*; Iizuka, Masatoshi*; Nohira, Toshiyuki*; Kitawaki, Shinichi; Kofuji, Hirohide

A novel pyroprocess is proposed for recovering actinides from spent nuclear fuels in which electrochemical reactions on a liquid Ga in molten chlorides are used. The proposed pyroprocess utilizes the large difference of alloy formation potential between actinides-liquid Ga and lanthanides-liquid Ga to achieve a higher separation efficiency of actinides from lanthanides than a conventional pyroprocess using a liquid Cd as a reaction medium. The present study investigated basic electrochemical behaviors of lanthanides, Ce and Nd, and actinides, U and Pu, on a liquid Ga electrode in LiCl-KCl melts. Alloying potentials, current efficiencies and activity coefficients in liquid Ga are presented which are the inevitable properties to evaluate the feasibility of the proposed process.