Browsing by Author "May, JR"

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    A conceptual design study of a low throughput reprocessing facility for nuclear fuel
    (Australian Atomic Energy Commission, 1967-11) Cairns, RC; May, JR; Baillie, MG; Farrell, MS
    The idea of reducing fuel reprocessing costs by changing reprocessing plant design philosophy is explained. It is shown how a significant reduction in unit reprocessing costs can lead to earlier recovery of nuclear material. A classification is given of some existing nuclear chemical reprocessing plants as a function of their maintenance philosophies. The feasibility of the rack concept is discussed for application to a conceptual low throughput reprocessing plant specifically designed for reprocessing fuel from the A.A.E.C.'s Dido-class reactor HIFAR. Laboratory and design development work is described. Preliminary cost estimates are given for a site at the Research Establishment, Lucas Heights, with maximum use of existing facilities, services, and plant. The study did not reveal any technical difficulties that would make the rack concept impractical. The concept of indirect maintenance for items of equipment which are likely to require frequent attention is technically feasible, and it appears possible to remove racks for repair of equipment by normal direct maintenance techniques. Additional development followed by plant construction and operation would be necessary to verify these conclusions and to establish any cost advantages. However, the cost estimates deduced at the start of the study did not change substantially during the course of the work.
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    Economics of the H.T.G.C.R. fuel cycle, Part 1 - pre-design cost study of fuel cycle facility
    (Australian Atomic Energy Commission, 1967-05) May, JR; Devine, JM
    A conceptual design study of a facility to recycle fuel from a beryllium oxide moderated high temperature gas -cooled pebble bed reactor has been made. For a facility to handle 300 kg of fuel per day, the capital cost is estimated as $A30 millions and the annual direct operating cost, excluding capital charges, as $A3-1 millions.
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    Graphite fuel studies, Part 2: fine grinding of artificial graphite
    (Australian Atomic Energy Commission, 1959-03) May, JR; Warner, RK
    Homogeneous dispersions of fissile and fertile material in graphite are being currently considered as fuel for high-temperature, gas-cooled nuclear reactors. A possible method of fuel preparation involves compaction of finely ground artificial graphite with U and Th metal powders. Size reduction of artificial graphite is therefore of interest in the preparation of graphite-fuel compacts. Reactor graphite has been successively size reduced in a jaw crusher, pin disc mill and ball mill to give material 50% finer than 9 microns, and with a B.E.T. nitrogen adsorption surface area ranging up to 18.4 m2/g. This variables in ball milling have been studied, and in particular it was found that Ni-hard balls gave a faster grinding rate, but a higher contamination than was obtained with steel balls. Leaching with boiling HCI was effective in removing contamination introduced by these grinding media. The Rosin-Rammler function, R = 100e - (x/x)n applied to the size distributions of the ground graphite. In the size range 70-1000 microns the distribution constant "n" equaled 1, which is consistent with publishing data for other materials. However, above and below this size range, the distribution constant approximated 2. This high value of n for the sub-sieve range has not been previously reported, but is not peculiar to artificial graphite as other materials were found to have a similar value of n.
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    Graphite fuel studies, Part 3 - compaction of graphite and mixtures of graphite and fissile and fertile materials
    (Australian Nuclear Science and Technology Organisation, 1961-05) May, JR
    Sound high density cylinders of graphite have been made by cold compacting finely ground artificial graphite at pressure of 60 t.s.i. Cylinders could be made only if the graphite used was 50 percent, finer than 10 microns and freshly ground. Storage of the powder in moist atmospheres or heating of the powder reduced its compacting properties. Uranium and thorium metal powder and uranium and thorium oxide up to 60 weight per cent, equivalent metals have been added to the graphite and sound cylinders made from the mixtures. The compacts have been heated to high temperatures (up to 2800°C) to convert the metals or oxides to carbides which rapidly hydrolyse in moist air. Measurements of compressive strength and density changes and investigation of the properties of the compacts on thermal cycling have been made. Compacts made from metal powders are considered satisfactory for use fuel for a High Temperature Gas Cooled reactor system provided their irradiation stability is satisfactory. Recommendations for further work are made.