The Phase diagram of LiCl-KCl-UCl system

Nakayoshi, Akira  ; Kitawaki, Shinichi ; Fukushima, Mineo ; Murakami, Tsuyoshi*; Kurata, Masaki 

In the pyrochemical reprocessing of spent metallic fuels, electrorefining is conducted in a molten salt of LiCl-KCl eutectic (59:41 mol%) with dissolved actinide chlorides (AnCl) at 773 K. Spent metallic fuels are dissolved in the molten salt at the anode, and actinide metals are deposited at the cathode. The concentration of AnCl in LiCl-KCl eutectic is assumed to be 2 mol%. However, the concentration of AnCl becomes higher in the vicinity of the anode during electrorefining, and the solubility of AnCl may affect the rate of anodic dissolution. Therefore, it is important for the process operation to clarify the phase diagrams of LiCl-KCl-AnCl systems. In the present study, LiCl-KCl-UCl ternary phase diagram in the range of 020 mol% UCl is investigated by a combination of X-ray diffraction method (XRD) and differential thermal analysis (DTA).