Review of Recent Advances in Electrochemical Processes in Molten Salt Electrolyte for Recycling Used Nuclear Fuel

Abstract

Recent advancements in nuclear technology, particularly in the development of small modular reactors (SMRs) and the implementation of enhanced safety protocols, have significantly increased the attractiveness of nuclear energy as a sustainable power source. This growing demand for nuclear energy, coupled with the proliferation of SMRs, has led to a heightened demand for uranium, consequently driving up its market price. As uranium resources become increasingly scarce, there is a growing interest in technologies that recycle used nuclear fuel or reuse as fuel. Pyroprocessing is an advanced technique for recycling used nuclear fuel from light-water reactors into metallic fuel suitable for fast reactors. This process, which relies on molten salt, involves the reduction of UNF to the metal via oxide reduction using a Li₂O–LiCl salt as an electrolyte. Subsequently, fuel components are recovered through electrorecovery methods, including electrorefining and electrowinning, utilizing a LiCl–KCl–UCl₃ salt. This review paper examines the critical technologies involved in oxide reduction and electrorecovery processes, which are essential for commercializing of these techniques. It provides a comprehensive overview of recent research and literature, with a specific emphasis on the development of electrode materials that enhance process efficiency, the production of UCl₃ for electrorecovery, and key advancements in electrowinning technology.