A hybrid acceleration method to pin-by-pin calculations using the heterogeneous variational nodal method

Abstract

As a continued research for our previous work, a hybrid method to accelerating pin-by-pin calculations based on the heterogeneous variational nodal method (VNM) is presented. Previously the coarse node acceleration method (CNA) was proposed for inner iterations. In this paper, the formulation of the generalized partitioned matrix method (GPM) to the heterogeneous VNM which accelerates outer iterations is elaborated. The hybrid utilization of the two methods is examined with the C5G7 problem and the small modular reactor problem. Numerical comparisons demonstrated that the hybrid acceleration method results in over ten-fold reduction in the total computational time.