Browsing by Author "Chapman, AG"

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    A compilation of experimental burnout data for axial flow of water in rod bundles
    (Australian Atomic Energy Commission, 1981-02) Chapman, AG; Carrard, G
    A compilation has been made of burnout (critical heat flux) data from the results of more thant 12000 tests on 321 electrically-heated water-cooled experimental assemblies each simulating to some extent the operating or postulated accident conditions in the fuel elements of water-cooled nuclear power reactors. The main geometric characteristics of the assemblies are listed and references are given for the sources of information from which the data were gathered.
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    The condensation of steam on the external surfaces of the shells of HIFAR heavy water heat exchangers during a loss-of-coolant accident
    (Australian Atomic Energy Commission, 1987-03) Chapman, AG
    A study of steam condensation rates on the HIFAR heavy water heat exchangers was undertaken to predict thermohydraulic conditions in the HIFAR containment during a postulated loss-of-coolant accident (LOCA). The process of surface condensation from a mixture of air and steam and methods for calculating the rate of condensation are briefly reviewed. Suitable experimental data are used to estimate coefficients of condensation heat transfer to cool surfaces in a reactor containment during a LOCA. The relevance of the available data to a LOCA in the HIFAR materials testing reactor is examined and two sets of data are compared. The differences between air/H2O and air/D2O mixtures are discussed. Formulae are derived for the estimation of the coefficient of heat transfer from the heat exchanger shells to the cooling water and a method of calculating the rate of condensation per unit area of surface is developed.
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    Out-of-pile burnout experiments in a full-scale simulation of an irradiation rig in a HIFAR hollow fuel element facility
    (Australian Atomic Energy Commission, 1986-06) Chapman, AG; Hargreaves, ND
    Flow measurement and burnout experiments were performed in an out-of-pile test rig which simulates the conditions of UO sub 2 irradiation rig in a hollow fuel element facility of the HIFAR reactor. One per cent of the coolant flow in the fuel element passed through the irradiation rig. A burnout heat flux of 90 W cm -2 was observed at the surface of an electrically-heated dummy irradiation can. When the coolant flow rate in the irradiation rig was increased by a factor of 2.5 the burnout heat flux rose by 30 per cent to 117 W cm - 2. A simple modification to the supporting frame for the cans improved the burnout heat flux by 3 per cent at 1 per cent of the coolant flow but enhanced it by 17 per cent at 2.5 per cent of the coolant flow. Of ten burnout events observed eight were located upstream of the end of the heated length of the can. The burnout results form a self-consistent credible set of data and provide a rational basis for the establishment of maximum permissible operating heat fluxes in irradiation rigs of the type simulated. Recommendations are made for the practical application of the results.