Effects of electrode configuration on the current density distribution of the electrolytic reducer

Pyroprocessing for the recycling of light water reactor spent fuel into metal nuclear fuel involves the electrolytic reduction process to convert oxides into metals. Optimization of the electrolytic cell is essential in the current engineering-scale development stage of electrolytic reduction research. This study investigates the effects of the conventional impermeable anode shroud, typically used in the development of laboratory-scale electrolytic reducers, and the effects of parallel multiple electrode configurations, aimed at the scale-up of the electrolytic reducer, on the current density distribution of the electrolytic reducer. The current density distribution was analyzed using COMSOL modeling. The exclusion of the impermeable anode shroud resulted in increased total currents under constant cell voltage conditions and contributed to the narrowing of the current density distribution on the electrodes. In addition, parallel multiple electrode configurations proved effective in increasing total currents and narrowing the current density distribution on the electrodes. These results emphasize the need to use a permeable anode shroud and a parallel multiple electrode configuration to scale-up the electrolytic reducer.