Using FRAM to determine enrichment of shielded uranium by portable electrically cooled HPGe detectors

Abstract

The capability of the FRAM software to accurately determine the enrichment of shielded uranium by portable electrically cooled HPGe detectors was studied. This can have applications in the future, e.g., for the verification of aged uranium-bearing products, scrap, and waste materials, especially during short notice random or unannounced inspections, when detector cooling with liquid nitrogen is not feasible. More than 7000 high-resolution gamma spectra of certified reference materials were taken by the ORTEC "Detective" detector under well-defined measurement conditions. Up to 16 mm of steel was used for shielding. The 235U enrichment of the reference materials varied from 0.31% to 4.46%. The settings of an existing FRAM parameter set were optimized and all the collected spectra were analysed using the default and the optimized parameter sets. The results obtained with these parameter sets are compared in this paper.JRC.G.II.6-Nuclear Safeguards and Forensic