Browsing by Author "McKay, MH"

Now showing 1 - 4 of 4
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    A derivation of the effective resonance integral in heterogeneous systems
    (Australian Atomic Energy Commission, 1959-08) Keane, A; McKay, MH; Cox, CD
    This paper is concerned with the evaluation of the effective resonance integral for a close-packed lattice of fuel elements in beryllium oxide moderator. For this evaluation the usual theory of resonance absorption is extended to allow for flux depression in the moderator. Further, the fuel elements under consideration consist of clusters of seven rods, so that it is necessary to determine the effective surface area for such a cluster. When the fuel elements are composed of U235, Th232 and Be atoms in the ratio of approximately 1:35:1200 and the BeO moderator occupies almost three and half times the volume of the fuel rods, the effective resonance integral is found to be almost about 60% of the value for a homogeneous system of the same composition.
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    The doppler coefficient for reactors containing thorium
    (Australian Atomic Energy Commission, 1960-06) Keane, A; McKay, MH; Clancy, BE
    The Doppler increase in the effective resonance integral has been calculated for a model absorber which approximates the resonance structure of Th232. The results indicate that for rods of pure thorium the increase depends approximately on the square root of the temperature and very good agreement is obtained with experimental values of: 1/1 - dI/dT. The calculations also show that the addition of scattering material to the fuel rods will lessen the temperature dependence of the increase in the effective resonance integral.
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    Equivalence relations for heterogeneous reactor systems
    (Australian Atomic Energy Commission, 1966-12) Keane, A; McKay, MH
    A derivation is given of an equivalence relation between heterogeneous and homogeneous systems which allows for close—packing without the need for a Dancoff correction and which includes fuels dispersed in granular form. An alternative derivation of the equivalence relation is also presented giving insight into the physical significance of the rational approximation.
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    Function arising from second order approximations to the effective resonance integral
    (Australian Atomic Energy Commission, 1965-11) McKay, MH; Pollard, JP
    A function K(θ,a1,aλ,x*0), which occurs in the evaluation of second order approximations to the effective resonance integral, is investigated. Various approximations to this function are given for a range of parameters appropriate to resonance calculations and a description is given of an economic numerical method of evaluating the function accurately.