B. Goddard, W.S. Charlton, S.M McDeavitt, “Real-Time Detection of UREX+3a Extraction Streams for Materials Accountancy”, 2009 Annual Meeting of the Institute of Nuclear Materials Management, Tucson, AZ, July 12-15, 2009.
Due to increased construction of nuclear power plants, current stockpile of used nuclear fuel, and a desire of the public to reduce the amount of this used nuclear fuel, reprocessing is gaining popularity. However, reprocessing facilities in non-weapon states must be safeguarded. To help create a safeguards strategy for non-weapons states gamma ray measurements from samples of the UREX+3a reprocessing method were made with a variety of detector types and times. It was determined that the errors from quantitative measurements were too large for safeguards purposes; however, a safeguards strategy based on qualitative gamma ray and neutron measurements was created. Self shielding and neutron damage to gamma detectors were also looked at. It was determined that there is no noticeable self shielding for internal pipe diameters less than 2 inches and that HPGe N-type detectors would be suitable for a neutron radiation environment. Gamma ray spectra were simulated in MCNP for UREX+3a reprocessed fuel that had a decay time of three years. A conclusion was reached that the safeguards approach proposed in this paper would best be suited as an addition to existing safeguard strategies.