Development of a molten salt electrorefining process suited for the recycling of HALEU fuel production scraps )

October 2023 – September 2027

High performance research reactors (HPRRs) are vital instruments in materials research, nuclear physics and nuclear medicine. Their high neutron flux irradiation capabilities were historically obtained by the use of HEU fuel. In light of nonproliferation there is a strong drive to convert existing HPRRs to high assay LEU (HALEU) and provide HALEU fuel solutions for future HPRRs. Innovative manufacturing techniques are needed to fabricate high density metallic HALEU fuel, with emphasis on UMo and U3Si2 types. Key steps are (i) the conversion of uranium oxides to its metallic form and (ii) recycling of production scraps to increase fabrication yield and thus U economy. Pyroprocessing is a combination of electrochemical operations in high temperature molten salt media developed for the reprocessing of spent nuclear fuels. Deployed as a batch process, it can be designed with a small footprint and has the possibility to provide low waste amounts. Electroreduction and electrorefining are key process steps in pyroprocessing.

The objective of this research project is the development of an electrorefining process suited to recycle HALEU production scraps. Separation efficiencies of the most common impurities together with Mo and Si will be determined. In-situ electrochemical and spectroscopic analysis techniques will be studied as tools to follow-up process parameters.