Fission product decontamination factors for plutonium separated by PUREX from low-burnup, fast-neutron irradiated depleted UO2

Experimental investigations to determine fission product separation from actinides (U and Pu) while employing the Plutonium Uranium Recovery by Extraction (PUREX) process to purify plutonium produced in a fast neutron irradiated depleted uranium dioxide (DUO2) target were conducted. The sample was a DUO2 pellet (0.256 wt% 235U) irradiated to a low-burnup (4.43±0.31 GW d/tHM) that was PUREX processed 538 days after neutron irradiation. Decontamination factors (DF) for the elements U, Mo, Ru, Ce, Sm, Sr, Pm, Eu, Nd, Pd, and Cd were measured with mass spectroscopy in two experiments using 30 vol% tri-n-butyl phosphate (TBP) in a kerosene diluent. The first experiment characterized Pu DFs for a single stage extraction and back-extraction, while the second experiment had multiple stages with the goal of achieving greater Pu recovery. The benchtop scale PUREX process had overall Pu recoveries of (83.4±9.5)% and (99.7±4.2)% for the first and second experiments, respectively.