Experimental testing and process simulation of flowsheets for the co-separation of uranium and plutonium using acetohydroxamic acid as a complexing agent

For the future recycling of spent nuclear fuels, reprocessing options that are more efficient and proliferation resistant will be needed. The development of an Advanced PUREX process using centrifugal contactors and the ligand aceto-hydroxamic acid (AHA) to only partially separate U and Pu is an innovative step in this regard. AHA acts as a hydrophilic complexing agent for Pu(IV), enabling its selective stripping from organic to aqueous phases in a modified PUREX process without the need for Pu(IV) reduction. A new series of experimental flowsheet tests of this Advanced PUREX process has been conducted using AHA to produce mixed (U, Pu, Np) and bulk U products in nitric acid, demonstrating the concepts. New process models have been developed to describe the effect of AHA on Pu(IV) extraction, thus enabling simulations of the experimental flowsheets. These models effectively describe the impact of AHA on Pu(IV) extraction and align closely with experimental outcomes, offering robust tools for future flowsheet optimization.