The calculation of neutron flux distribution for two-dimensional light water fuel assembly

The transmission probability method is developed for solving neutron flux distribution in tow-dimensional light water reactor fuel asscmbly. The interior flux within a mesh is assumed to be linearly dependent on X and Y coordinates. At the mesh surfaces the linear space distribution and the P1-approximation for the anisotropic angular distribution are considered. Simple expressions for the expansion coefficients are derived, which is determined by outgoing and incoming currents and renewed after each iteraction. Based on the proposed method, the 2-D code TMP2D has been encoded and a series of 2-D assembly benchmark problems have been tested. The numerical results are in good agreement with those of Sn, surface flux transport, discrete node transport and collision probability methods