Browsing by Author "Miller, R"

Now showing 1 - 9 of 9
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    Australia's new high performance research reactor
    (International Group On Research Reactors, 2003-03-24) Miller, R; Abbate, PM
    A contract for the design and construction of the Replacement Research Reactor was signed in July 2000 between ANSTO and INVAP from Argentina. Since then the detailed design has been completed, a construction authorization has been obtained, and construction has commenced. The reactor design embodies modern safety thinking together with innovative solutions to ensure a highly safe and reliable plant. Also significant effort has been placed on providing the facility with diverse and ample facilities to maximize its use for irradiating material for radioisotope production as well as providing high neutron fluxes for neutron beam research. The project management organization and planning is commensurate with the complexity of the project and the number of players involved.
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    Australian research reactors spent fuel management: the path to sustainability
    (European Nuclear Society, 2016-03-13) Finlay, MR; Miller, R; Dimitrovski, L; Domingo, X; Landau, P; Valery, J; Laloy, V
    Since the late 1950’s, ANSTO has successfully operated three research reactors in Australia: HIFAR (1958-2007), MOATA (1961-1995) and OPAL (2006- Specific strategies were developed and implemented for the management and disposition of spent fuel from HIFAR and MOATA. They included strategic considerations, technical options, fuel characteristics, storage capacity, operational constraints and associated implications. In addition, the operating licenses of the Australian reactors have required the identification of spent fuel disposition arrangements, i.e. the “deferment” strategy of storage indefinitely is not acceptable. Disposition then employed three routes with direct disposal in the USA under the US-DOE FRRSNFA Program and reprocessing in France by AREVA, and in the UK by the UKAEA. Both reprocessing routes included return of vitrified waste. ANSTO and AREVA have worked together since the late 1990’s on the disposition of uranium aluminide (UAlx) spent fuel from HIFAR. Today, ANSTO is committed to develop a lifetime strategy for management and disposition of uranium silicide (U3Si2) spent fuel from OPAL. AREVA’s ability to offer an integrated solution for storage, transport, reprocessing, waste return and long-term management, including addressing individual customer needs (type of fuel, timelines, quantities, final waste management strategy,...), has provided ANSTO with a viable spent fuel management strategy, for OPAL’s lifetime.
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    New research reactor for Australia
    (Technicatome, 1992-05-18) Miller, R
    HIFAR, Australia's major research reactor, was commissioned in 1958 to test materials for an envisaged indigenous nuclear power industry. HIFAR is a Dido type reactor which is operated at 10 MW. With the decision in the early 1970's not to proceed to nuclear power, HIFAR was adapted to other uses and has served Australia well as a base for national nuclear competence; as a national facility for neutron scattering/beam research; as a source of radioisotopes for medical diagnosis and treatment; and as a source of export revenue from the neutron transmutation doping of silicon for the semiconductor industry. However, all of HIFAR's capabilities are becoming less than optimum by world and regional standards. Neutron beam facilities have been overtaken on the world scene by research reactors with increased neutron fluxes, cold sources, and improved beams and neutron guides. Radioisotope production capabilities, while adequate to meet Australia's needs, cannot be easily expanded to tap the growing world market in radiopharmaceuticals. Similarly, neutron transmutation doped silicon production, and export income from it, is limited at a time when the world market for this material is expanding. ANSTO has therefore embarked on a program to replace HIFAR with a new multi-purpose national facility for nuclear research and technology in the form of a reactor: a) for neutron beam research, - with a peak thermal flux of the order of three times higher than that from HIFAR, - with a cold neutron source, guides and beam hall, b) that has radioisotope production facilities that are as good as, or better than, those in HIFAR, c) that maximizes the potential for commercial irradiations to offset facility operating costs, d) that maximizes flexibility to accommodate variations in user requirements during the life of the facility. ANSTO's case for the new research reactor received significant support earlier this month with the tabling in Parliament of a report by the Australian Science and Technology Council on recommended priorities for government expenditure on major national research facilities over the next ten years. A new research reactor was one of seven proposals recommended by the Council for priority during that period. As basis for ANSTO's normal activities is nuclear science and technology rather than reactor development, it will be necessary to purchase much of the nuclear specific technology and hardware with the emphasis being on modern but proven technology. In January 1992 ANSTO commenced a two year preliminary engineering and financial study that will define the user requirements, assess the availability of reactor designs compatible with those requirements, complete preliminary design and provide a detailed costing and schedule for the provision of the facility. The report of this study will form the basis of a submission to Government for funding for detailed design and construction. Initial operation of the reactor is scheduled for 2003. The overall project schedule is shown.
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    The OPAL Reactor
    (International Group On Research Reactors, 2007-03-11) Miller, R; Irwin, T; Ordoñez, JP
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    The OPAL Reactor
    (European Nuclear Society, 2007-03-11) Miller, R; Irwin, T; Ordoñez, JP
    The OPAL reactor went critical for the first time on 12 August 2006 and achieved full power for the first time on 3 November 2006. This has been a successful project characterised by extensive interaction with the project’s stakeholders during project definition and the use of a performance-based turnkey contract which gave the contractor the maximum opportunity to optimise the design to achieve performance and cost effectiveness. The contactor, INVAP SE, provided significant in-house resources as well as project managing an international team of suppliers and sub-contractor deliver the project’s objectives. A key contributor to the project’s successful outcomes has been the development and maintenance of an excellent working relationship between the ANSTO and INVAP project teams. Commissioning was undertaken in accordance with the IAEA recommended stages. The main results of hot commissioning are reviewed and the problems encountered examined. Operational experience since hot commissioning is also reviewed.
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    Preferential amorphisation of Ge nanocrystals in a silica matrix
    (Australian Institute of Physics, 2005-01-31) Ridgway, MC; Azevedo, GDM; Elliman, RG; Wesch, W; Glover, CJ; Miller, R; Llewellyn, DJ; Foran, GJ; Hansen, JL; Nylandsted Larsen, A
    Relative to bulk crystalline material, Ge nanocrystals in a silica matrix exhibit subtle structural perturbations including a non-Gaussian inter-atomic distance distribution. We now demonstrate such nanocrystals are extremely sensitive to ion irradiation. Using transmission electron microscopy, Raman spectroscopy and extended x-ray absorption fine structure spectroscopy, the crystalline-to-amorphous phase transformation in -8 nm diameter nanocrystals and bulk crystalline material has been compared. Amorphisation of Ge nanocrytals in a silica matrix was achieved at an ion dose -100 times less than that required for bulk crystalline standards. This rapid amorphisation of Ge nanocrystals is attributed to the preferential nucleation of the amorphous phase at the nanocrystal/matrix interface, the pre-irradiation, higher-energy structural state of the nanocrystals themselves and an enhanced nanocrystal vacancy concentration due to the more effective trapping of irradiation-induced interstitials at the nanocrystal/matrix interface and inhibited Frenkel pair recombination when Ge interstitials are recoiled into the matrix. To demonstrate the significance of the latter, we show ion irradiation of -2 nm diameter nanocrystals yields their dissolution when the range of recoiled Ge atoms exceeds the nanocrystal bounds.
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    Preferential amorphisation of Ge nanocrystals in a silica matrix
    (Elsevier, 2004-09-05) Ridgway, MC; Azevedo, GDM; Elliman, RG; Wesch, W; Glover, CJ; Miller, R; Llewellyn, DJ; Foran, GJ; Hansen, JL; Nylandsted Larsen, A
    Extended X-ray absorption fine structure and Raman spectroscopies have been used to compare the crystalline-to-amorphous phase transformation in nanocrystalline and polycrystalline Ge. We demonstrate Ge nanocrystals are extremely sensitive to ion irradiation and are rendered amorphous at an ion dose ∼40 times less than that required to amorphise bulk, crystalline standards. This rapid amorphisation is attributed to the higher-energy nanocrystalline structural state prior to irradiation, inhibited Frenkel pair recombination when Ge interstitials are recoiled into the matrix and preferential nucleation of the amorphous phase at the nanocrystal/matrix interface. © 2005 Elsevier B.V
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    Progress on construction of Australia's replacement research reactor (OPAL)
    (International Group On Research Reactors, 2005-09-12) Miller, R
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    Replacement research reactor for Australia
    (International Group On Research Reactors, 1998-04-29) Miller, R
    In 1992, the Australian Government commissioned a review into the need for a replacement research reactor. That review concluded that in about years, if certain conditions were met, the Government could make a decision in favour of a replacement reactor. A major milestone was achieved when, on 3 September 1997, the Australian Government announced the construction of a replacement research reactor at the site of Australia's existing research reactor HIFAR, subject to the satisfactory outcome of an environmental assessment process. The reactor will be have the dual purpose of providing a first class facility for neutron beam research as well as providing irradiation facilities for both medical isotope production and commercial irradiations. The project is scheduled for completion before the end of 2005. © 1998 The Author