Real-Time Detection of UREX+3a Extraction Streams for Materials Accountancy

Due to increased construction of nuclear power plants, currentstockpiles of used nuclear fuel, and a desire of the public to reducethe amount of this used nuclear fuel, reprocessing is gaining popularity.However, reprocessing facilities in non-weapon states must besafeguarded. To help create a safeguards strategy for non-weaponsstates, gamma ray measurements from samples of the UREX+3areprocessing method were made with a variety of detector types andtimes. It was determined that the errors from quantitative measurementswere too large for safeguards purposes; however, a safeguardsstrategy based on qualitative gamma ray and neutron measurementswas created. Self-shielding and neutron damage to gammadetectors were also looked at. It was determined that there is nonoticeable self-shielding for internal pipe diameters less than twoinches and that HPGe N-type detectors would be suitable for aneutron radiation environment. Gamma ray spectra were simulatedin Monte Carlo Neutron Particle Transport Code for UREX+3areprocessed fuel that had a decay time of three years. A conclusionwas reached that the safeguards approach proposed in this paperwould best be suited as an addition to existing safeguard strategies.