Performance test of the HGU code for uranium isotopic analysis by gamma spectroscopy

For technical assistance in the nuclear nonproliferation regime and nuclear forensics, non- destructive assay (NDA) techniques for an analysis of the nuclear materials in laboratories or in the field are being developed in South Korea. HyperGam-U (HGU) was developed by Seoul National University and Korea Atomic Energy Research Institute (KAERI) to determine the uranium enrichment based on gamma- and x-ray spectroscopy. The K-alpha x-ray region (89-101 keV) of the uranium spectrum, which contains 13 peaks for U-235 and U-238, was mainly used for the analysis. For the performance test, eight certified reference material (CRM) uranium samples covering from low to high enrichment were measured using a high-resolution planar high-purity germanium (HPGe) detector and analyzed using the HGU code. Corrections for the attenuation and true coincidence summing (TCS) were performed, and the goodness of fit was improved by a few percentage points. The enrichment analysis biases of the HGU code from the certified values did not exceed 2% for all measured samples.