Abstract
For about every 18 months, the pressurized water reactor needs to be reloaded. Usually, fuel procurement consists of three fuel cycles. Based on the provided energy demand of each cycle, the fuel vendor will propose the composition and price of the fresh fuel assemblies. But how to decide the composition of fresh fuel assemblies is not known. Depending on each cycle’s required energy, enrichment and integral fuel burnable absorber (IFBA) number of each cycle are determined. Moreover, the current cycle status is affected by the preceding two cycles’ core condition; it will increase the difficulty of design. Thus, the motivation of automatic design is conceived. In this study, the harmony search (HS) algorithm is applied to automatically search the composition of fresh fuel assemblies. HS is inspired by the composition of harmony, and it is a metaheuristic optimization algorithm. Advantages of HS are using less mathematical conditions, no requirement of an initial solution, and considering the existing solutions to produce new solutions. These features make HS more flexible and be able to search better solution. After the composition of fresh fuel assemblies are decided, the selected fuel assemblies was permuted according to the fixed LPs, which were calculated by SIMULATE-3 to obtain moderator temperature coefficient, hot channel factor, and boron concentration at the end of cycle. After the proper FA composition is determined, the accurate LP design is searched to guarantee the satisfactory requirements. The developed program was coded by using language C. SIMULATE-3 code was used to calculate core status. The Maanshan unit I cycle 18 to 21 was designed to verify the effectiveness of HS. The results show that searching for tandem cycles and searching for successive cycles are able to find the composition of fresh fuel assemblies which satisfy the constraints. Since the computing time of these two methods are almost the same, it is difficult to conclude which method is better.