Modeling Research Reactor Fuel Plate Hotspots with the Thin Layer and Thermal Contact Feature in the COMSOL Multiphysics® Software

M. J. Richards [1], A. E. Ruggles [2], J. D. Freels [3], ,
[1] Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, USA
[2] Department of Nuclear Engineering, University of Tennessee, Knoxville, TN, USA
[3] Research Reactors Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA

发布日期 2016

One challenge with converting nuclear research reactors to low enrichment fuels is the thermal-fluid performance. Local areas of high temperature, known as hotspots, limit reactor performance and thus require accurate modeling. A simplified fuel plate model is eveloped to compare traditional FEA techniques with the thin layer and thermal contact features in the COMSOL Multiphysics® software for modeling regions of low thermal conductivity and high energy generation that produce hotspots. Temperatures, conductive heat fluxes, and energy balances are reported. TL and TC offer similar performance with < 0.3% error in energy balance for all cases. Both experience oscillations in boundary, normal heat flux at discontinuities in conductivity that decrease with grid refinement and increased element order. TC offers options that make it more appropriate for hotspot models.