Browsing by Author "Silver, JM"

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    Experiments in extrusion, Part 2 - the hot extrusion of beryllium.
    (Australian Atomic Energy Commission, 1964-12) Wright, WJ; Silver, JM; Spain, SW
    A technique for the hot extrusion of beryllium powder within a mild steel sheath has been developed. Limitations exist with this technique in the control of extruded dimensions, particularly on complex sections or where the sheath thickness is greater than about 0.020 inch. The use of pre-consolidated powder billets is recommended to reduce the danger of the sheath buckling or splitting during extrusion and to improve the surface finish and dimensions of the product. Pick-up of oxygen and nitrogen by the beryllium was observed where the beryllium was not completely sealed from the atmosphere during heating and extrusion. This factor affected the mechanical properties of the material, particularly hardness. The mechanical properties of the sections were determined as a function of extrusion conditions; these properties are sensitive to the choice of extrusion temperature, presumably reflecting a tendency for residual work hardening to increase at the lower extrusion temperatures.
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    Experiments in extrusion, Part 3 - the mechanics of extrusion of beryllium.
    (Australian Atomic Energy Commission, 1964-12) Wright, WJ; Silver, JM; Whatham, JF
    The extrusion pressures determined for beryllium and mild steel over a wide range of reductions in area at temperatures between 750ºC and 1050ºC are significantly lower than those reported previously. This is attributed to better control of temperature in the work reported, the effects of container friction were assessed and the coefficient of friction between tooling and billets was estimated as 0.03 — 0.035 when using graphite lubricants. The flow of metal in extrusion through various dies was examined using gridded billets; the velocity profiles and extent of the plastic field were determined. The work was applied to a study of the shapes developed from plane interfaces in the billets during extrusion; the interface shape necessary in die original billet to produce a plane interface in the extruded section was determined and applied in the basic extrusion technique to improve the yield of product.
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    Fabrication of beryllia-coated, fuelled beryllia spheres for in-pile fission product release tests
    (Australian Atomic Energy Commission, 1966-01) Reeve, KD; Clare, TE; Silver, JM; Bridgford, KC
    Three sees of beryllia-coated, fuelled beryllia spheres were made for fission product release testing in a sweep capsule irradiation rig Results of various pre-irradiation tests are presented and discussed, and a summary of fission gas release results is included, Gas release rates were expected to vary inversely as the beryllia density However, the release rate was lowest for the loading with an intermediate density and was highest for that with the highest density One or more of several structural factors may have changed the behaviour from that expected.
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    Nuclear materials management procedures.
    (Australian Nuclear Science and Technology Organisation, 1987-10) Veevers, K; Silver, JM; Quealy, KJ; van der Steege, E
    This manual describes the procedures for the management of nuclear materials and associated materials at the Lucas Heights Research Laboratories. The procedures are designed to comply with Australia's nuclear non-proliferation obligations to the International Atomic Energy Agency (IAEA) bilateral agreements with other countries and ANSTO's responsibilities under the Nuclear Non-Proliferation (Safeguards) Act 1987. The manual replaces those issued by the Australian Atomic Energy Commission in 1959 1960 and 1969.
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    Papers presented to the AAEC symposium on uranium processing, Lucas Heights, 20-21 July, 1972
    (Australian Atomic Energy Commission, 1972-09) Miles, GL; Harltey, FR; Butler, RD; Henley, KJ; Cooper, RS; Kelly, A; Goldney, LH; Canning, RG; Gooden, JEA; Baillie, MG; Thomas, JA; Hardy, CJ; Alfredson, PG; Costello, JM; Silver, JM; Richmond, M
    Review of nuclear fuel cycles and world trends; Conventional processes to produce yellow cake; Carbonate leaching of uranium ores, a review; The application of mineralogy to uranium ore processing; Extraction investigations with some Australian uranium ores; Planned changes in the Mary Kathleen treatment plant for future operations; Possible trends and methods for the production of high purity products; Review of methods and technology for the reproduction of high purity products; Review of methods and technology for the production of uranium hexafluoride; Capital and production costs for the production of uranium hexafluoride; The market for Australian conversion services.
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    Plutonium and Japan: two discussion papers. The balance of plutonium supply and demand in Japan. The shipment of plutonium to Japan.
    (Australian Nuclear Science and Technology Organisation, 1992-06) McMillan, MJ; Silver, JM
    Japan lacks indigenous energy resources and has chosen nuclear power as a means of achieving the energy security and diversity essential to economic growth. The reprocessing of spent fuel and recycling of the nuclear materials have been part of Japan’s nuclear policy since the 1950s. The plutonium and uranium recovered from spent fuels are regarded as pseudo-domestic energy resources. To achieve the least dependence on overseas resources for nuclear power, particular importance is placed on reprocessing and fuel fabrication within Japan. Japan s current nuclear fuel recycling plan, approved by the Atomic Energy Commission (AEC) in August 1991, predicts that, by the year 2010, Japan’s total fissile plutonium supply will be about 85 tonnes. Fifty five tonnes are to be recovered from domestic reprocessing (5 tonnes from the Tokai reprocessing plant and 50 tonnes from the Rokkasho commercial reprocessing plant) while 30 tonnes are to return from Britain and France. It foresees this being in balance with planned consumption in Fast Breeder Reactors (FBRs) of "22-35 tonnes, Advanced Thermal Reactors (ATRs) ~8 tonnes and Light Water Reactors (LWRs) "50 tonnes. This latest plutonium plan places an increased importance on the utilisation of mixed uranium-plutonium (MOX) fuel in LWRs. Table l summarises Japan’s anticipated cumulative plutonium supply and demand. The important variables in achieving or modifying this balance will be the timing and output of the Rokkasho plant, the number and type of fast reactors and the pace at which the planned program of LWR MOX recycling is implemented. Different sources use various quantities in discussing plutonium stocks, usually either total plutonium (i.e. the mass of all the isotopes present) or fissile plutonium (Puf) (i.e. the mass of only the fissionable isotopes) plutonium 239 and plutonium 241. As the later is the term used by Japanese sources, it has been adopted, where possible, here. The mixture of plutonium isotopes in the plutonium recovered from spent fuel reprocessing depends on the isotopic composition of the initial fuel, the reactor design and operating conditions and the length of time for which the fuel has been irradiated. The fissile isotopes, plutonium 239 and plutonium 241, make up approximately 70% of total plutonium recovered from spent fuel irradiated to usual burnups in an LWR.
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    Uranium resources and requirements
    (Australian Atomic Energy Commission, 1975-08) Silver, JM; Wright, WJ
    The amount of uranium available to support the world's nuclear power programs depends on the price which users are prepared to pay for its recovery. As the price is raised, it is attractive to recover uranium from lower grade deposits, thereby increasing the total quantity available. About 3.5 million tonnes of uranium is estimated to be available to the Western World in deposits which could be recovered for present day costs of less that $A30 per kilogram. This amount is believed to be sufficient to meet the nuclear power program until the turn of the century. There are good prospects for the discovery of further deposits (particularly in Africa, Canada, South America and Australia) which could extend these resources. If the Fast Breeder Reactor is introduced by about 1990, it could ultimately decrease the uranium from about 2020 onwards. The total amount of uranium required to support the Light Water Reactor power program until this happens would be about 7 million tonnes. On present evidence, this could be available from high grade deposits, together with some low grade deposits and by-product sources at costs less than $A60 per kilogram. If the Fast Breeder Reactor is not introduced as expected, the demand for uranium will continue to increase and it could be necessary to recover uranium from black shales or ultimately from sea water at costs ranging up to $A300 per kilogram. Australia has about 19% of the reasonably assured resources of uranium in the Western World recoverable at costs of less than $A20 per kilogram, or about 9% of the resources (reasonably assured and estimated additional) recoverable at costs of less than $A30 per kilogram. Australia's potential for further discoveries of uranium is good. Nevertheless, if Australia did not export any of these resources it would probably have only a marginal effect on the development of nuclear power; other resources would be exploited earlier and prices would rise, but not sufficiently to make the costs of nuclear power unattractive. On the other hand, this policy could deny to Australia real benefits in foreign exchange earnings, employment and national development.