The TCLUST1 Transient LMFBR Intersubassembly Heat Transfer Code

The TCLUSTI computer code has been developed to study the transient thermal performance of a liquid metal fast breeder reactor (LMFBR) subassembly that is thermally coupled to its six immediate neighbors. Each of the seven subassemblies may be either a reflector subassembly, which contains a single solid hexagonal rod. or a pin-bundle subassembly. The TCLUSTI analytical model, which is based on conservation of energy, and the numerical solution method, which employs successive over-relaxation (SOR) are described. Analytical temperature predictions are compared with data obtained from a natural-convective flow test performed in Experimental Breeder Reactor II. Good agreement is obtained between the analytical and measured results.