Heat removal from spent fuel subassemblies of LMFBRs

Accurate evaluation of the cooling capability from a spent fuel subassembly in gas atmosphere is one of the major concern in the safety design for the fuel handling system of a LMFBR. In this study, a heat transfer experiment and two-dimensional analysis for 19-elements subassembly was carried out in order to clarify the basic heat transfer characteristics in the fuel subassembly configuration. The experimental results indicated that thermal radiation and thermal conduction are the dominant heat transfer mechanism in a fuel bundle, on condition the gas forced cooling system is out of operation. On the other hand, the results of two-dimensional analysis by multilateral element method showed a good agreement with experimental results. (author)