Anodic Process of Electrorefining Spent Nuclear Fuel in Molten LiCl-KCl-UCl3/Cd System

Abstract

This article summarizes the experimental results and engineering aspects regarding the anodic process for electrorefining 100 irradiated driver fuel assemblies, a demonstration project for the Department of Energy (DOE) to treat spent nuclear fuel. The focus is on the anode due to its unique geometry (fuel dissolution baskets loaded with chopped irradiated fuel segments), complex chemical compositions, highly demanding process goals and their significance to the entire spent fuel treatment process. Chemical analysis results of cladding hull samples were used as the key criteria to evaluate the effectiveness of the uranium dissolution and noble metal retention. Parametric study indicated that the diffusion of reactants in the porous fuel matrix was the rate-controlling step to the uranium dissolution from the chopped fuel segments. Anode resistance was the most effective parameter to assess the completeness of uranium dissolution and noble metal retention.