Journal of Nuclear Fuel Cycle and Waste Technology

Pyroporcessing of spent nuclear fuel generates a considerable amount of LiCl-KCl eutectic waste salt containing radioactive rare earth (RE) chlorides. In this study, a series of processes, which consist of a phosphorylation/distillation process and a solidification process, were performed to minimize volume of the LiCl-KCl eutectic waste salt and solidify a residual waste into a stable form at a relatively low temperature. Over 99wt% of RE chlorides in LiCl-KCl eutectic salt was converted and separated into REPO4 in the phosphorylation/distillation process using a mixture of Li3PO4-K3PO4. The separated REPO4 was solidified into a homogeneous and fine-grained form at 1,050℃ using LIP(Lead Iron Phosphate) as a solidification agent. The final waste volume was reduced below about 10% through the series of the processes.

Keywords

Pyroprocessing of spent nuclear fuel,LiCl-KCl eutectic salt,Rare earth,Phosphorylation,Distillation,Solidification