Abstract
CHARACTERIZATION OF UNKNOWN URANIUM CONTAINING MATERIAL FOR NUCLEAR SAFEGUARDS AND SECURITY PURPOSES
S. Shawky*
ABSTRACT
This paper investigates the applicability of material fingerprints (nuclear forensics) for material origin identification. Samples of unknown grinded rocks, ores and ore concentrates were analysed. For their characterization, the concentrations of major, minor elements, uranium and their secular equilibrium progenies were studied. Uranium content and its isotopic ratios, do not fully characterize the tested material, while these signatures and levels of concentration can probably help in determining processes of production, the stage and the possible origin material. Major elements such as Na, Al, Mn, K, Ca, Fe and Mg were determined using Scanning Electron Microscope- Energy Dispersive X-ray Analyses (ESM-EDX), while minor elements such as Sr, Zr, Mn, Cr, Ni, Cu, Zn, La, Ce, Y, Nb, U, Th, Pb, and As were analysed using Inductively Coupled Plasma Atomic Emission spectrometer (ICP-AES). For chosen isotopes compositions were determined using Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and ? spectrometric analysis. Results show difference between samples in trace elements content, reflecting the different origin of samples. Rare Earth Elements (REE) signature and abundance patterns were tested as predictive signatures since direct-comparison samples were not available. This predictive approach, although more challenging than direct comparison, proven to be a sensitive tool to define source of origin among fully unknown samples. This demands the need for national database and proper searching engine for correlating the unknown material to a certain origin listed in the reference database. The database should list the fingerprints of different uranium ores and the ore concentrates at each production stage.
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