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

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.