Electrochemical reduction of uranium oxide fuel in a molten LiCl/Li ₂O system

This article reports the experimental results of the electrochemical reduction of uranium oxide fuel in a bench-scale apparatus at Argonne National Laboratory. The experiments were performed in a molten LiCl/Li₂O electrolyte at 650°C under an argon atmosphere in a hot cell. The purpose of the bench-scale experiments was to understand the mechanisms of predominant reactions at the anode and cathode, and to establish operating conditions prior to initiating electrochemical reduction experiments with spent LWR oxide fuels. Cyclic voltammetry was utilized to explore the process limitations and to investigate the kinetic parameters of the electrode reactions. Depleted uranium oxide was used to determine the current efficiency and rate-limiting step for the electrochemical reduction process. A surrogate LWR fuel was also tested to assess fission product distributions and their impact on the electrode processes.