Irregular Region Transformation Method for Hexagonal Assembly Homogenization and Its Numerical Validation

In order to simplify the calculation process of hexagonal assembly homogenization,and enhance the adaptability of homogenization method for hexagonal geometry,a simple irregular region transformation method is proposed in this paper,by which these irregular regions such as assembly wrapper and water gap can be transformed into regular hexagon with the constraint condition that material mass remains constantly.The numerical results show that it is a very accurate and efficient method for the prediction of assembly reactivity and normalization power distribution versus burnup.