A nonlinear iteration method based on one node expansion

A nonlinear iterative method based on one node expansion is presented. In this method, we firstly solve the coarse mesh finite diffusion (CMFD) equations, in which the nonlinear coupling coefficients are involved, to obtain the nodal averaged fluxes. Then we compute the interface neutron currents in one node, instead of two nodes, to get the nonlinear coupling coefficients. After that we solve the CMFD equations with renewed coupling coefficients to obtain improved nodal average fluxes. After several iterations the nodal averaged fluxes and can be obtained accurately. The numerical results of two benchmark problems show that this new method has the potential to accurately solve multidimensional problems with less computing time compared with Nodal Green Function Method (NGFM). (author)