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    Measurement of concentration of tungsten suspensions and density of liquid sodium by gamma ray absorption
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Watt, JS; Lawther, JS
    Gamma ray absorption techniques have been applied to measure the density of various media, and the theory of selecting the appropriate energy gamma ray to give optimum sensitivity of density determination for a homogeneous system is outlined. A gauge to determine the concentration of tungsten powder suspended in water in a concentration range of O to 8 gm. tungsten/c.c. suspension, has been developed. In this apparatus the mean tungsten concentration, 0.08 gm./c.c., can be measured to an accuracy of approximately +-0.0015gm./c.c. In the case of liquid sodium contained in o stainless steel vessel, preliminary experiments indicate that the density may be measured to an accuracy of +-0.01gm./ c.c. and that 0.01gm./c.c. transient changes in density occurring in a few seconds can be resolved.
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    The future of nuclear fuel reprocessing in Australia
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Miles, GL
    An attempt is made to predict the nature and scale of the nuclear fuel reprocessing industry which might be expected to develop in Australia up to about I975, and to indicate the kind of technical advances which will be required to achieve this.
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    The philosophy and practice of radioactive waste disposal
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Temple, RB
    This general review is largely concerned with the problems of disposing of the large amounts of highly-radioactive waste that will result from a large-scale nuclear power program employing fission reactors. The dangers of dilution-dispersal are outlined, and particular attention is drawn to the possibility of biological reconcentration of the dispersed radioactivity. The conclusion is reached that it is imperative to find some method of permanently storing the activity in a non-leochable solid form, if the fullest use is to be made of nuclear power production. At present the "temporary expedient" of tank storage in liquid form is the only practicable method, but by I965 other methods will have to be found.
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    The control and instrumentation of the reactor HIFAR
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Page, G
    A brief description of the reacting core of HIFAR is given, together with some data on the reactivity balance. The principles of the coarse, fine and safety control systems are outlined. Mention is made of the various installed thermal neutron flux measuring channels. The electrical safety and interlock circuits and the ways in which they influence the operation of the reactor are discussed. An outline is given of the other associated instrumentation such as health monitors and general industrial instruments.
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    Heat transfer in homogeneous gas-cooled reactors
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) de Vahl Davis, G
    The heat source distribution in a nuclear reactor is a function of neutron flux, fuel loading, and core temperature, each of which is a function of position. In certain types of solid fuel gas-cooled reactors, the fuel distribution is such that the reactor may be regarded as homogeneous. This paper describes the method of calculating the temperature distribution in the core of such a reactor. A cyclindrical core is assumed, and the variations of coolants flow and outlet temperature with radius are found. As a first approximation the dependence of neutron flux on temperature is taken to be small and the flux is assumed to have been calculated on the basis of uniform core temperature. using this flux distribution, the first core temperature distribution is found. Subsequent flux distributions can be calculated to refine the values of temperatures.
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    Liquid metal fuel reactors
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Alder, KF
    The advantages and disadvantages of a liquid metal fuel reactor system are outlined in relation to other possible power reactors. Liquid metals which are possible fuel carriers and coolants are discussed, and in particular a comparison is drawn between a solution-type fuel using bismuth and a dispersion-type using sodium. The reasons for the choice of a sodium dispersion fuel for the A.A..E.C. research project are presented and the problems posed by such a reactor system are summarised.
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    Materials for the control of nuclear reactors
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Wright, WJ; Nicholson, KP
    The desirable properties of neutron absorbers are discussed, and the investments for the equivalent absorption in various materials are calculated. Physical and metallurgical limitations exist in the use of boron and cadmium, and the investment for blackness compared to burn-up in hafnium is unattractive. The rare earths, gadolinium, samarium and europium are discussed; dispersions of the oxides in steel are suggested for use as control elements in future high temperature reactors.
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    Possible developments in nuclear fuel cycles in Australia
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Baxter, JP; Watson-Munro, CN
    The need for nationally integrated nuclear fuel cycles is stressed and, based on a number of speculative assumptions, some calculations are made of the order of requirements of fissile and fertile material.
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    The development of radiochemical facilities at Lucas Heights
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Miles, GL; Sangster, DF
    A description is given of the recently completed radiochemical laboratories at Lucas Heights. Design problems are discussed, as well as initial operating experience.
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    Some oxide ceramics as reactor materials
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Reeve, KD
    Although the conventional advantages of ceramics lie in their favourable high temperature properties reactor technology has not yet made use of these properties, mainly because of their uncertain behaviour under irradiation. The fabrication and properties of beryllia, uranium dioxide and thoria, and of mixed oxide systems, are discussed.
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    Reactor irradiation techniques
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Hickman, BS
    The problems encountered in carrying out precise investigations of the effects of neutron irradiation on the properties of materials are discussed. Various experimental techniques which have been developed to overcome these problems are described with particular reference to techniques which could be used in the Australian Atomic Energy Commission's research reactor, HIFAR.
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    Analytical chemistry in atomic energy
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Smythe, LE
    The requirements for analytical chemistry in atomic energy are outlined and the impact of increasing instrumentation is discussed. Some recent developments in analytical chemistry instrumentation are reviewed and their possibilities and uses in the atomic energy field are assessed. These include automatic coulometry, square wave polarography, gamma spectrometry, low background beta counting, infra-red spectrometry, mass spectrometry, emission spectrography, X-ray spectrography and vacuum fusion analysis.
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    Acid leaching and anode dissolution of graphite - moderated fuels
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Hyde, KR; O'Connor, DJ; Woodhead, JL
    Results of nitric acid leaching and anodic disintegration processing studies of two types of homogeneous graphite moderated fuels ore reported. ZN nitric acid leaching at 90-100°C appears suitable as the primary processing method, whereby uranium and thorium are obtained in solution suitable for solvent extraction. Anodic disintegration in 2N nitric acid is a satisfactory wet method of breaking down the graphite fuel assemblies, but the disintegration process does not give the required uranium and thorium recoveries. lt has not been possible to assign any electrochemical action to the anodic solution of uranium and thorium carbides.
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    Radio-isotopes in Australian industry and research
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Gregory, JN
    Radio-isotopes play a very prominent part in industry in the United States, the United Kingdom and other highly industrialised countries. These countries also use radio-isotopes, mainly as tracers, very extensively in basic and applied research, and in clinical medicine. Australian industry and research has been relatively slow to accept these new techniques, as illustrated by statistics in Table 1. The relatively low figure for the U.S.A. can be explained by their national policy in radioisotope production. In general, United States shipments from Oak Ridge are individually larger in quantity than the U.K. shipments. Many United States shipments are bulk supplies for commercial firms, who split them up for sale to the user in much smaller units. The United Kingdom organisations at Harwell and Amersham sell direct to the user, or in a form ready for use in almost all cases. Also, small shipments under general licence are not included in the U.S.A. data. If the U.S.A. figures were on the same basis as the United Kingdom data, the number of shipments per unit of population figure would be much larger than indicated in Table 1.
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    Neutron diffraction on HIFAR
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Sabine, TM
    A brief account of the use of neutron diffraction as a complementary technique to X-ray diffraction in crystallographic analysis is given. The spectrometers to be installed on HIFAR are described and the experimental limitations of the technique discussed.
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    Gas-cooled reactors of a mixed fuel-moderator type
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Dalton, GCJ
    Reactors of this type may use any of the moderators, graphite, beryllium oxide or beryllium, and one of the coolant gases hydrogen, helium, carbon dioxide, nitrogen or other suitable gas to be selected on the grounds of compatibility with the moderator and circuit materials and engineering suitability. The uranium233-thorium fuel cycle is the most suitable because the conversion factor possible with this system is greater than with the Z plutonium-uranium238 cycle. Because there is no necessity for lumping the fuel, the moderator may be used to dilute the fuel and to increase the surface available for heat transfer to the coolant. This dilution should also improve the burn-up possible before the 6 fuel element suffers physical disintegration. The fuel and fertile material may be mixed uniformly with the moderator, or may be in a thin, enriched layer near the surface of the element. The fuel elements may be rods, spheres, plates, or bricks, pierced by coolant channels. Research will be directed towards the production of a high integrity fuel element, the solution of problems of compatibility of gas and moderator, control of fission products and reprocessing and refabricating fuel elements. It is expected that this type of reactor will have particular application in the power range of 5 to 5OMW.
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    The HIFAR oscillator
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Nicholson. KP; Pryor, AW
    A description is given of a pile oscillator which will enable thermal absorption cross-section measurements to be made on HIFAR. The apparatus is in course of construction. The principal design factors are discussed, with particular reference to the effects of scattering by the sample, and the extension of the range of cross-section measurements to include moderators such as graphite and beryllium.
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    The design and construction of HIFAR
    (Melbourne University Press on behalf of The Australian Atomic Energy Commission, 1958-06-02) Roberts, WH
    A brief description is given of the design and construction Commission's of the Australian Atomic Energy reactor HIFAR, located near Sydney or Lucas Heights. The design is based on that of the British DIDO, a high flux, heavy water moderated and cooled reactor having a maximum thermal neutron flux of 1014 neutrons/sq. cm/sec., and a maximum heat output of l0 megawatts.
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    Symposium on movement of granular material and structure, fluid flow and heat transfer in packed beds
    (Australian Atomic Energy Commission, 1967-02-16) Australian Atomic Energy Commission Research Establishment
    The Research Establishment has acquired a considerable amount of experimental information on the movement of granular material and on the structure, fluid flow and heat transfer in random and ordered packings of spheres and some information on non-spherical shapes. TheCommission believes that this work will undoubtedly prove to be of wide interest in the many fields of Engineering and Applied Science (Chemical reactors pebble bed heaters and stores? water filters, soil mechanics concrete structure} rock hoppers, silos, etc). The object of the Symposium is to ensure efficient dissemination of the Commission's work to scientists and engineers in Government Departments Indus trial Organizations and Universities and that the relevant work of other people is properly related to the Commission's efforts.
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    A method of studying ball flow by ditigal computer
    (Australian Atomic Energy Commission, 1967-02-16) Bennett, NW
    Ball flow may be studied with the aid of a digital computer. The method consists of calculating elastic forces due to simple interactions and using these forces to track individual balls. Any shape of container may be simulated exactly, although protrusions into the container present difficulties, To date, only two-dimensional systems have been studied, but the method may be extended easily into three dimensions at a penalty of a tenfold increase in calculation timer This is caused by the extra dimension, the greater number of neighbours per ball and a more complete elastic analysis which must be applied in three dimensions Since elastic forces are being studied, the vibrations due to these forces must be followed, For hard balls this may involve real time intervals of milliseconds which may take seconds to calculate on the IBM 7040 computer on site. A circulation model may be easily set up by arranging for balls which have fallen out of the bottom of a container to be replaced at the top of the array of balls. The forces between balls and between a ball and the container wall are known at all times and may be given as output by the machine. The position and velocity of all balls is also known, and from the ball positions the voidage may be calculated. A model involving friction has been investigated in simple situations. The friction model allows balls in contact to move against each other for a limited distancer A force may be associated with the distance of slip and the force between the balls. The point of maximum slip corresponds to the point of limiting friction. An estimate is given of the cost to perform simple experimenter