MINOR ACTINIDE SEPARATION: SIMPLIFICATION OF THE DIAMEX-SANEX STRATEGY BY MEANS OF NOVEL SANEX PROCESSES

摘要

The separation of An(Ⅲ) from PUREX raffinate has previously been demonstrated by applying a DIAMEX process (i.e., co-extraction of An(Ⅲ) and Ln(Ⅲ) from HAR) followed by a SANEX process (i.e., selective extraction of An(Ⅲ) from the DIAMEX product containing An(Ⅲ) + Ln(Ⅲ)). In line with process intensification issues, more compact processes have been developed: Recently, a 1c-SANEX process test was successfully performed, directly extracting An(Ⅲ) from PUREX HAR. More recently, a new i-SANEX process was successfully tested. This process is based on the coextraction of An(Ⅲ) + Ln(Ⅲ) into a TODGA solvent, followed by a selective back-extraction of An(Ⅲ) by a water soluble complexing agent, in this case SO_3-Ph-BTP. In both cases, good recoveries were achieved, and very pure product solutions were obtained. However, both 1c-SANEX and i-SANEX used non-CHON chemicals. Nevertheless, these processes are a simplification to the DIAMEX + SANEX process as only one solvent is used. Finally, the new i-SANEX process is the most compact process.