Corrosion-Resistant Microplasma Anode Array for High-Temperature Molten Salt Electrolysis and In-Situ Analysis

Abstract

Developing a suitable corrosion-resistant anode material and monitoring the molten salt composition changes are two core challenges in the electrolytic reduction process of spent nuclear fuels. In this work, gaseous microplasma anode was employed to induce the electrochemical reduction of UO2 pellets, achieving a high reduction degree. Compared to traditional commonly used anode materials (Pt, carbon, Mo, and W), microplasma electrodes presented a highly corrosion resistance and remained stable during long-term operation (>150 hours) in LiCl-Li2O molten salt. And the salt composition changes could be in-situ monitored by collecting the atomic emission spectroscopy in the microplasma. Moreover, a microplasma array was designed to amplify the electrolysis current as well as monitor the components in different regions of molten salt, addressing the demands of industrial-scale applications. It was calculated that the cost of anode for reducing 1 kg UO2 could be reduced for more than 90% by using microplasma instead of Pt electrodes, indicating that microplasma is a promising corrosion-resistant anode for high-temperature molten salt electrolysis and in-situ analysis.