Browsing by Author "Evans, T"

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    ANSTO Nuclear Foresnics Research Facility: method development and applications
    (Australian Nuclear Science and Technology Organisation, 2012-10-16) Wotherspoon, ATL; Hill, DM; Keegan, EA; Evans, T; Blagojevic, N; Loi, E; Toole, K; Griffiths, GJ; Smith, KL; Reinhard, MI
    The IAEA defines nuclear forensic science, commonly shortened to “nuclear forensics” as ‘the scientific analysis of nuclear or other radioactive material, or of other evidence that is contaminated with radioactive material, in the context of legal proceedings, including administrative, civil, criminal or international law’1. In broad terms, the job of the nuclear forensic scientist is to support investigations that involve a nuclear security event. Nuclear forensic examinations will provide information to key questions posed by the investigative authority: What is it? How much is there? Is there any more out there? Is it ours? As an investigation proceeds other questions that may arise are; How old is it? What contaminants are present? Does it pose a threat? Who is responsible for the loss? Where did the material come from? Many of the techniques required to answer these questions are based on environmental radiochemistry. The Nuclear Forensic Research Facility (NFRF) at ANSTO is developing expertise in analysing nuclear and other radioactive material material based upon the precepts of the ‘model action plan’ of the International Technical Working Group for Nuclear Forensics (ITWG) and other best practices. We are also investigating the validity of traditional forensic techniques (like fingerprints and DNA) on evidence contaminated with radioactive material alongside more novel parameters, e.g. the isotopic composition at the ‘bulk’ material and the micro scale using advanced micro-analytical techniques. We are moving towards the integration of a range of radio analytical techniques such as mass spectrometry, electron microscopy and the simulation/modelling of material production signatures, to provide a range of different information streams to assist attribution. With each advance in our technical competencies we enhance our means to ensure the security of nuclear or other radioactive material.
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    Development and evaluation of radiological decontamination procedures for documents, document inks, and latent fingermarks on porous surfaces
    (Wiley-Blackwell, 2010-05) Parkinson, A; Colella, M; Evans, T
    Criminal acts such as an attack utilizing a radiological dispersal device (RDD or dirty bomb), the manufacture of such a device, or the illicit trafficking of radioactive materials would warrant a criminal investigation. This could involve the collection, transportation, and analysis of radiologically contaminated trace evidence. But are law enforcement agencies and forensic scientists capable of dealing with this? This research investigates the decontamination efficacy of two decontamination techniques (chemical and physical) designed for the removal of radiological material from documents of forensic importance. The impact that these procedures have on the development of latent fingermarks and the forensic analysis of the inks on these documents is also studied. It was found that slight changes in the color and chemical composition of a variety of document inks and a destruction of fingermark ridges occurred after chemical decontamination. Physical decontamination had no impact on these parameters. © 2010, Wiley-Blackwell.
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    The impact of alpha-emitting contamination on the handling and analysis of forensic evidence
    (Australian Nuclear Science and Technology Organisation, 2012-10-16) Evans, T; Toole, K; Brew, DRM; Colella, M
    A nuclear security event, where for example radioactive material is used in a malevolent act or where material is found outside of regulatory control will require an investigation. That investigation may require the collection, handling, and analysis of forensic evidence and hence it is highly likely that some of the physical evidence associated with such an event would have been exposed to radiation and possibly be contaminated with nuclear or other radioactive material. These scenarios present significant challenges to traditional approaches to crime scene investigation and it is well recognised by the international nuclear forensics community for the need to assess the application of existing forensic techniques to radiation-exposed samples and the implementation of procedures for safe and efficient examination of evidence contaminated with radioactive material. Previously, at the Australian Nuclear Science and Technology Organisation’s Nuclear Forensics Research Facility the effect of gamma radiation on forensic evidence as well as the impact of decontamination on evidence has been explored. This presentation will report on considerations for handling evidence contaminated with radioactive material and detail the latest developments in evaluating the application of forensic techniques to evidence exposed to, or contaminated with alpha-emitting radionuclides.
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    Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia
    (Elsevier, 2014-07-15) Mohiuddin, K; Strezov, V; Nelson, PF; Stelcer, E; Evans, T
    The improved understanding of mass and elemental distributions of industrial air particles is important due to their heterogeneous atmospheric behaviour and impact on human health and the environment. In this study, particles of different size ranges were collected from three sites in Australia located in the vicinity of iron and steelmaking industries and one urban background site with very little industrial influence. In order to determine the importance of the type of industrial activity on the urban atmospheric quality, the industrial sites selected in this study were in the close proximity to two blast furnace operated and one electric arc furnace based steelmaking sites. The chemical compositions of the collected air particles were analysed using the proton induced X-ray emission (PIXE) technique. This study revealed significantly higher metal concentrations in the atmospheric particles collected in the industrial sites, comparing to the background urban site, demonstrating local influence of the industrial activities to the air quality. The modality types of the particles were found to be variable between the mass and elements, and among elements in the urban and industrial areas indicating that the elemental modal distribution is as important as particle mass for particle pollution modelling. The highest elemental number distribution at all studied sites occurred with particle size of 0.1 μm. Iron was found as the main dominant metal at the industrial atmosphere in each particle size range. The industrial Fe fraction in the submicron and ultrafine size particles was estimated at up to 95% which may be released from high temperature industrial activities with the iron and steelmaking industries being one of the major contributors. Hence, these industrial elemental loadings can highly influence the atmospheric pollution at local urban and regional levels and are required to consider in the atmospheric modelling settings. © 2014, Elsevier B.V.
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    Recovery of latent fingermarks from evidence exposed to ionizing radiation
    (Wiley-Blackwell, 2009-05) Colella, M; Parkinson, A; Evans, T; Lennard, C; Roux, C
    Continual reports of illicit trafficking incidents involving radioactive materials have prompted authorities to consider the likelihood of forensic evidence being exposed to radiation. In this study, we investigated the ability to recover latent fingermark evidence from a variety of substrates that were exposed to ionizing radiation. Fingermarks deposited on common surfaces, including aluminum, glass, office paper, and plastic, were exposed to doses ranging from 1 to 1000 kGy, in an effort to simulate realistic situations where evidence is exposed to significant doses of radiation from sources used in a criminal act. The fingermarks were processed using routine fingermark detection techniques. With the exception of glass and aluminum substrates, radiolysis had a considerable effect on the quality of the developed fingermarks. The damage to ridge characteristics can, in part, be attributed to chemical interactions between the substrate and the components of the fingermark secretions that react with the detection reagents. © 2009, Wiley-Blackwell.