QUANTIFYING THE IMPACT OF SHIELDING AND COLLIMATION ON
ISOTOPIC MEASUREMENTS OF SPECIAL NUCLEAR MATERIAL

The use of HPGe and gamma spectroscopy for the purpose of determining the isotopic composition of plutonium and uranium has a well-documented history in Non-Destructive Assay (NDA) and IAEA Nuclear Measurement Accountancy and Control (NMAC) measurements. Commercially available applications such as MGA/MGAU and FRAM allow for the isotopic analysis to be automated, but there are basic detector performance criteria that are typically required to produce high-quality results with low uncertainty estimates. Often the quality of an algorithm within a software application is paired with the excellent peak shape, high-efficiency, and portability of the measuring instrument. Recently, Mirion developed a new portable detector that supports both a high quality peak shape response in conjunction with relatively high efficiency. This paper presents the performance measurement results of uranium standards of varying enrichments accomplished with the Mirion Technologies Aegis™ BE5030 portable detector and spectrometer. The isotopic and quantitative analyses were performed with FRAM. The measurements were made with Aegis™ detectors with a range of resolution performance levels. The results of the isotopic analysis and activity complete with uncertainties are compared with those of historically acceptable laboratory instruments.