Characterisation of sealed radioactive source for nuclear forensic purposes

A study characterized sealed radioactive sources ( 60 Co, 137 Cs, and 241 Am) for nuclear forensic analysis, focusing on their physical, macroscopic, and radiological properties. Results revealed specific features, such as stamped or engraved information, that served as valuable signatures for nuclear forensic investigation. Corrosion observations provide valuable insights into the condition of the source and historical context. Gamma-ray spectra analysis revealed clear distinctions, including a scattering peak in cylindrical 60 Co and 137 Cs disk sources (200-500 keV), which was absent in the cup-style 241 Am source. Unusual peaks in the gamma spectra of 60 Co, 137 Cs, and 241 Am sources suggested potential impurities or background radiation. This was indicated by non-Gaussian shapes and significant counts per second at specific energy levels. X-ray radiography effectively highlights nuclear material characteristics, emphasizing density, uniformity, and internal structure. This analysis contributed to the development of a National Nuclear Forensic Library (NNFL) and enhanced Malaysia’s capability in nuclear forensic investigations related to radioactive sources found outside regulatory control.