J. Allred “Experimental Analysis of Plutonium Product and Raffinate Waste Streams from a PUREX Process on a low Burn-up, Fast Neutron Irradiated DUO2 Pellet”, M.S. Thesis, Nuclear Engineering, Texas A&M University, College Station, TX (2016).
Experimental investigations of separating actinides (uranium and plutonium) from fission products (FPs) were conducted using a modified Plutonium Uranium Recovery by Extraction (PUREX) process. The sample under investigation was from a low burn-up (&&< 5 GWd/tU), depleted uranium dioxide (DUO2) pellet (~13 milligrams) irradiated in a fast neutron spectrum in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). This sample simulated the DUO2 blanket region of a Fast Breeder Reactor (FBR) which was removed at low burn-up for weapons-grade plutonium (WGPu) recovery. The potential to misuse the material generated in this type of reactor prompts interest in a detailed analysis of the FPs present in the separated plutonium product and raffinate streams. A detailed understanding of these unique compositions would aid nuclear forensics activities for source attribution in the case of smuggled plutonium interdiction or at an inspection of a reprocessing plant to catch the misuse of such a plant. The objective of the study was to quantify the fission product decontamination factor (DF) for PUREX process steps while separating and purifying plutonium. Aliquots of the dissolved neutron irradiated DUO2 sample containing FPs and WGPu, underwent three modified PUREX decontamination cycles with products (organic and aqueous solutions) from each process step being analyzed via high-resolution gamma spectroscopy. Distribution ratios and DF values were calculated for nuclides of interest to be incorporated into a larger nuclear forensics database.