Abstract
The fuel lattice design must be executed before the reload design of a boiling water reactor (BWR). The fuel assembly (FA) consists of dominate zone, shutdown margin zone, and critical power ratio zone. The goal of a fuel lattice design is to permute the fuel rods so that the specific value of lattice average enrichment and infinite multiplication factor can be achieved, and also low local peaking factor (LPF) can be obtained. The neutron cross section library of the designed lattice was established by the CMSLINK and then the core status such as thermal limits, cold shutdown margin and cycle length were calculated to guarantee the lattice design meet the design requirements. Automatic design of boiling water reactor fuel lattice pattern were developed using the particle swarm optimization (PSO) algorithm and the local search algorithm. The PSO and the local search algorithm are effective optimization algorithms for combinatorial optimization problem and the heuristic rules were adopted to reduce search space and computation time. The reference data had been used by Kuosheng nuclear power plant. The fuel assembly is divided into five zones. The highest zone and the lowest zone in the axial direction are natural uranium, which doesn’t need to design lattice. As for the rest three zones in the middle region, there are called the dominate zone, shutdown margin zone and critical power ratio zone. In this study, these three zones were designed. The developed program was coded with C language, which was executed in the HP C8000 workstation. The cross section was calculated by CASMO-4 code.