Analysis of long life LWR fuel benchmark by CP based interface current methods

Abstract

The LWR benchmark suite is a set of problems that was proposed for validating lattice calculations at pin and assembly level for long life fuel. The LEU and MOX fuel assembly designs consider fissile loading and gadolinium loading which are significantly higher than current fuel designs. In this paper, we describe the solution to this benchmark problem by the lattice burnup code VISWAM. This code solves the transport equation by the interface current method based on 2-D collision probability (2DCP). The incoming and outgoing angular fluxes at the pin-cell interfaces are expanded in terms of PN half space expansions, where N is the order of the expansion. We have considered three expansions, double P0, double P1 and double P2 for evaluating the escape and transmission probabilities. The higher order methods are more accurate where flux anisotropy is high.