Browsing by Author "Roberts, SK"

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    Comparing results of X-ray diffraction, µ-Raman spectroscopy and neutron diffraction when identifying chemical phases in seized nuclear material, during a comparative nuclear forensics exercise
    (Springer Nature, 2018-01-24) Rondahl, SH; Pointurier, F; Ahlinder, L; Ramebäck, H; Marie, O; Ravat, B; Delauney, F; Young, EL; Blagojevic, N; Hester, JR; Thorogood, GJ; Nelwamondo, AN; Ntsoane, TP; Roberts, SK; Holliday, KS
    This work presents the results for identification of chemical phases obtained by several laboratories as a part of an international nuclear forensic round-robin exercise. In this work powder X-ray diffraction (p-XRD) is regarded as the reference technique. Neutron diffraction produced a superior high-angle diffraction pattern relative to p-XRD. Requiring only small amounts of sample, µ-Raman spectroscopy was used for the first time in this context as a potentially complementary technique to p-XRD. The chemical phases were identified as pure UO2 in two materials, and as a mixture of UO2, U3O8 and an intermediate species U3O7 in the third material. © The Author(s) 2018. This article is an open access publication.
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    Nuclear forensic analysis of an unknown uranium ore concentrate sample seized in a criminal investigation in Australia
    (Elsevier, 2014-07) Keegan, EA; Kristo, MJ; Colella, M; Robel, M; Williams, R; Lindvall, R; Eppich, G; Roberts, SK; Borg, L; Gaffney, AM; Plaue, J; Wong, HKY; Davis, J; Loi, E; Reinhard, MI; Hutcheon, I
    Early in 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. During the search of the laboratory, a small glass jar labelled “Gamma Source” and containing a green powder was discovered. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterise and identify the material and determine its provenance. Isotopic and impurity content, phase composition, microstructure and other characteristics were measured on the seized sample, and the results were compared with similar material obtained from the suspected source (ore and ore concentrate material). While an extensive range of parameters were measured, the key ‘nuclear forensic signatures’ used to identify the material were the U isotopic composition, Pb and Sr isotope ratios, and the rare earth element pattern. These measurements, in combination with statistical analysis of the elemental and isotopic content of the material against a database of uranium ore concentrates sourced from mines located worldwide, led to the conclusion that the seized material (a uranium ore concentrate of natural isotopic abundance) most likely originated from Mary Kathleen, a former Australian uranium mine. © 2014 Elsevier Ireland Ltd.