Design the fuel loading pattern. Loading pattern optimization methods in commercial light water reactors

The theories of loading pattern optimization, the methods and the tools using by PWR and BWR are stated. Needs for core design and loading pattern optimization, operating of PWR/BWR, designs of loading pattern, optimization of the loading pattern and design variables, the basic theories of loading pattern optimization, the optimization tools of loading pattern in Japan are explained. The basic theories consist of the determinism methods, the probability methods and heuristic method. Four tools such as INSIGHT (PWR), Pearls^th (PWR), FINELOAD (BWR) and ePrometheus (BWR) are described by outline, principles, characteristics, functions, and application examples. These tools are a great success of limiting the seek area and short-time calculation using the high speed simulation method of core functions. (S.Y.)