Nuclear Fuel Separations

In this work, three isomeric forms of N, N’-diethyl, N, N’-ditolyldipicolinamide (EtTDPA) were synthesized. The elements thorium through americium, which make up a significant portion of the actinides in used nuclear fuel (with the exception of curium), and two fission products, molybdenum and technetium, were tested for their ability to be extracted by EtTDPA into a polar fluorinated diluent from nitric acid solutions at varying concentrations of both nitric acid and organic ligand. These ligands were then further analyzed for their stability when subject to the harsh conditions inflicted during used fuel reprocessing. Degradation products were determined and the effect of their presence on the extraction and separation of the actinide and lanthanide elements was investigated. Finally, thermodynamics of the complexation between EtTDPA and neodymium were investigated by spectroscopic, calorimetric, and solvent extraction methods. The data presented here will hopefully be used in the future ligand design and implementation in solvent extraction systems for the reprocessing of used nuclear fuel