VERA is a suite of multiphysics codes which uses MPACT to model neutron transport in light water reactors (LWRs) [1]. In this paper, we validate MPACT by modeling critical experiments conducted at the IPEN/MB-01 and B&W facilities. We modeled critical loading experiments with a variety of different fuel pins and materials placed in the core. The experiments were modeled in two dimensions using MPACT and an axial buckling term. Default mesh parameters exist in MPACT for modeling larger reactor cores, and a mesh convergence study was performed to find appropriate mesh parameters for modeling the smaller critical reactors. The keff results show a consistent bias and small standard deviation for the IPEN/MB-01 reactor and a small bias and small standard deviation for the B&W facility. Overall, the results show that MPACT performs well for modeling small critical reactors.
VERA-CS VALIDATION OF CRITICAL EXPERIMENTS