An application of the domain decomposition method into the boundary element method for solving the multi-region neutron diffusion equation

This paper presents a technique for solving the neutron diffusion equation with the boundary element method based on the domain decomposition method. In this technique, the domain region is decomposed into homogeneous regions. The boundary conditions on the common boundary of decomposed regions and the multiplication factor are initially assumed. The boundary conditions on the other boundary are given. The neutron diffusion equation is solved iteratively at two levels of a hierarchical structure: first, the boundary element method is applied to solve the neutron diffusion equation of each homogeneous region under given assumed boundary conditions and multiplication factor. These assumed values are then modified to satisfy the continuity conditions for the neutron flux and neutron current. The proposed technique is useful for multi-region problems with a large number of regions. (C) 1998 Elsevier Science Ltd.