A study on the recovery of actinide elements from molten LiCl–KCl eutectic salt by an electrochemical separation

Abstract

Pyroprocessing is a prominent way for the recovery of the long-lived elements from the spent nuclear fuel. Electrorefining is a key technology for pyroprocessing and generally composed of two recovery steps—deposition of uranium onto a solid cathode and the recovery of TRU (TRansUranic) elements. In this study, it was investigated on electrochemical separation of actinides to develop an actinide recovery system in a molten LiCl–KCl eutectic salt. In the electrorefining experiment, uranium was successfully separated from cerium. The effects of the anode material and the surface area were investigated during the electrolysis experiments for a more efficient electrorefining system. Anode potential decreased with an increasing anode surface area, however, an anode effect was observed in case of a complicated anode structure for high surface area. Glassy carbon was found to be the best anode material among the molybdenum, graphite, glassy carbon, and oxide materials. It was found that the solid cathode with a perforated ceramic container could be one of the candidates for a salt clean-up process to remove residual actinide elements in the salt after the recovery step.