Development and Implementation of a Newton-BICGSTAB Iterative Solver in the FORMOSA-B BWR Core Simulator Code

An assessment of coupling algorithms for nuclear reactor core physics simulations

“…The next solution approach consists of a full JFNK solver using the nonlinear function evaluation described by Eq. (13). Recall that this selection requires performing full cross section processing at every linear iteration of the Krylov solver.…”

“…Additionally, steady-state coupling between neutron diffusion and thermal hydraulics using Newton's method (not JFNK) was studied in Refs. [13] and [16]. A significant distinguishing feature between these studies and the current work is that all of the previous studies used nuclear cross sections that were either fixed or allowed to vary in a prescribed, analytic manner.…”

“…In this study, we investigate the performance of Anderson acceleration and JFNK solvers compared to Picard iteration on multiphysics problems that couple 3D discretizations of the radiation transport and heat transfer equations along with a simple subchannel flow model for modeling of pressurized water reactors (PWRs). Although Newton and JFNK methods have been used previously for neutronics-only problems [10,11,12] and even for multiphysics problems [13,14,15,16,17], previous studies have used only few-group nuclear cross sections with analytic temperature variation. In this study we consider the impact of utilizing many energy groups with on-line generation of cross section data for use by the neutronics solver.…”