OPTIMIZATION OF PRESSURIZED-WATER REACTOR SHUFFLING BY SIMULATED ANNEALING WITH HEURISTICS

Simulated-annealing optimization of reactor core loading patterns is implemented with support for design heuristics during candidate pat tern generation. The SIMAN optimization module uses the advanced nodal method of SIMULATE-3 and the full cross-section detail of CASMO-3 to evaluate accurately the neutronic performance of each candidate, resulting in high-quality patterns. The use of heuristics within simulated annealing is explored. Heuristics improve the consistency of optimization results for both fast- and slow-annealing runs with no penalty from the exclusion of unusual candidates. Thus, the heuristic application of designer judgment during automated pattern generation is shown to be effective. The capability of the SIMAN module to find and evaluate families of loading patterns that satisfy design constraints and have good objective performance within practical run times is demonstrated. The use of automatic evaluations of successive cycles to explore multicycle effects of design decisions is discussed.