Reduction in Workload of BWR In-Core Fuel Shuffling by New Optimization Methods

In this paper, new optimization algorithms for the in-core fuel shuffling sequence of a boiling water reactor (BWR) are proposed to reduce outage time. During the short outage of a BWR, fuel shuffling can be a critical path in the periodic overall plant inspection. Therefore, a reduction in operation time for in-core fuel shuffling is essential to improve the plant capacity factor. For BWR in-core fuel shuffling, the shuffling sequence should be selected carefully since a fuel shuffling operation may affect those following it. Furthermore, several constraints must be satisfied during the in-core fuel shuffling of a BWR; e.g., two fuel assemblies must be inserted diagonally in a cell to fix the position of a control blade in it. Therefore, it is difficult to optimize BWR in-core fuel shuffling. In order to resolve this issue, new optimization methods are proposed, and the performances of some optimization algorithms are compared. Test calculations in actual BWR plants reveal that the workload for in-core fuel shuffling can be reduced by the proposed methods. The results of this paper will contribute to increasing the plant capacity factor by reducing the outage time.