Partitioning of High Level Waste

The partitioning and transmutation (P&T) nuclear fuel cycle is to separate the minor actinides and long-lived nuclides from high level waste (HLW), and then transmute these elements into stable or short lived nuclides in a reactor or an accelerator to dramatically reduce the long-term hazard and the volume of highly radioactive waste.

The research on the partitioning of HLW started in the early 1980s at the institute. A commercial reagent, trialkyl phosphine (TRPO), was found to have high affinity to actinides. Therefore, a partitioning process, TRPO extraction process, has been established to extract uranium and the transuranium elements from HLW. This process is considered as one of the most promising partitioning processes in the world. The actinides can be separated into three groups: Am(Cm)+lanthanides, Np+Pu and U. The further effective separation of Am (Cm) from lanthanides is a key step to realize the transmutation of minor actinides. To achieve that, a highly effective separation technology for Am (Cm)/lanthanides by extraction with a commercial reagent, Cyanex 301, has been developed in recent years, and it is universally acknowledged as a breakthrough in this field.