Methodology for identification of depleted metallic uranium and natural metallic uranium by portable gamma...

The requirement to distinguish between depleted metallic uranium (DU) and natural metallic uranium (NU) is essential in nuclear forensics, regulatory enforcement, nuclear fuel fabrication and environmental monitoring. Traditional laboratory-based methods offer high accuracy but are impractical for on-site measurement. This research develops a portable gamma spectrometry-based methodology for identifying DU and NU in real-time, non-destructively. The study utilizes a NaI(Tl) based gamma spectrometer to measure characteristic emissions from uranium isotopes and its daughter products. Key gamma peaks, particularly those at 92 keV (²³⁴Th) and 186 keV (²³⁵U), were analysed to derive isotopic ratios indicative of the material type. Emphasis was given on choosing right gamma peak and adjustment for x-ray contribution in 92 keV peak. Estimated activity ratio of ²³⁵U to ²³⁴Th of five natural uranium samples was greater than or equal to 0.046 and the activity ratio of five depleted uranium sample found to be less than 0.046, which validated the methodology. The results demonstrate that, with proper calibration, and spectral analysis, portable gamma spectrometry can serve as an effective tool for real-time uranium isotope identification in applications ranging from nuclear safeguards and non-proliferation to environmental monitoring and emergency response.