Challenges and operational experiences towards demonstration of high temperature molten salt electro-refining of hot U-Zr

Pyro-processing of spent metal fuels is a high-temperature electro-refining process aimed at separation and electro-deposition of actinides from the fission products, by exploring the thermodynamic stabilities of metal chlorides of actinides and fission products in eutectic molten salts of LiCl–KCl melt. Demonstration of this process requires a hot cell facility with a stringent atmosphere of controlled oxygen and moisture levels less than 50 ppm, since the process involves hygroscopic and corrosive materials. In this context, a laboratory-scale pyro-process facility was set up in the hot cell facility and to meet the process requirements, the cell was augmented and equipped with special equipment developed in-house. The challenges encountered and operational experiences during a demonstration of electro-refining of irradiated U-6Zr (wt%) at 500 °C using molten eutectic LiCl-KCl, in the augmented hot cell facility are detailed in this paper. (author)