Electrochemical Reduction of UO[sub 2] in Molten CaCl[sub 2] or LiCl

Abstract

To develop an electrochemical reduction technique for the reprocessing of nuclear fuels, the reduction behavior of at the cathode and the anode reactions were investigated in both and LiCl salt baths. In the at about , was reduced into metal over the potential range vs the . The reduced uranium metal cohered due to the high temperature and a dense metal skin covered the surface of the disk sample. It prevented the transportation of oxygen from the inside to the bulk salt and the reduction often stopped with remaining inside. A significant underpotential deposition of calcium metal was observed. In the LiCl at , was reduced into metal over the potential range vs the . The disk sample was satisfactorily reduced because the LiCl melt could permeate into the sample. The current efficiency of reduction in the LiCl was much better than in the . The anodic currents for oxygen and carbon oxide gas evolutions were verified in cyclic voltammograms of the platinum and glassy carbon electrodes. At the platinum surface, and yielded in the and LiCl, respectively.