ANISOTROPIC SCATTERING TREATMENT FOR THE NEUTRON-TRANSPORT EQUATION WITH PRIMAL FINITE-ELEMENTS

Three approaches are presented to treat anisotropic scattering in neut ron transport. The approaches are based on the even-odd-parity flux fo rmalism and yield three different second-order equa- tions for the eve n-parity flux. The first one is based on the total elimination of the odd-parity flux of the second-order equation. In the other two approac hes, anisotropic scattering contributions are homogenized and incorpor ated into the collision term. The numerical solutions of these equatio ns are implemented in the CRONOS code for pressurized water reactor co re calculations and are done with a finite element spatial approximati on and the discrete ordinates methods (S-N) for the angular variable. Numerical results are presented for critical problems (k(eff))in x-y g eometry. Comparisons with the APOLLO2 assembly code show the accuracy and the efficiency of the proposed algorithms.