A New Nodal S_N Transport Method for Three-Dimensional Hexagonal Geometry

Abstract

A new nodal SN transport method has been developed so as to perform accurate transport calculations in three-dimensional (3-D) hexagonal geometry. In the present method the neutron angular distributions of intra-node fluxes and transverse-leakage are represented using the S_N quadrature set, and the spatial distribution of neutron source is approximated by a quadratic polynomial expansion. Additionally, the authors have applied the nodal-equivalent finite difference algorithm to 3-D hexagonal geometry in order to establish a stable and efficient iterative scheme,
The present method has been applied to a fast reactor benchmark problem. The results of the present method agree well with those of a Monte Carlo method, the difference in k_eff being less than 0.05%Δk. This shows high accuracy of the present method.