Estimation of material balance in pyrometallurgical partitioning process for TRUs from HLLW

A pyrometallurgical partitioning process has been proposed and studied by CRIEPI. In this process, more than 98% of alkali metals were separated in a denitration step. Almost all of the another elements were converted to chlorides from oxides in a chlorination step. Separation experiments by means of multiple batch extraction was also carried out in the LiCl-KCl/Bi system, and more than 99% of each TRU was recovered. The material balance of solutes and solvents in the partitioning process was estimated from the experimental results of each step in the process. The refining salt, Cd, Bi, and Pb as solvent, Li as reductant, and generated chlorine gas can be recycled to the process. This process is, therefore, expected to generate less secondary radioactive waste in comparison with an aqueous process and should require relatively compact facilities. (author)