Validating COMSOL multiphysics for VVER-1000 whole-core-steady-state via AER benchmark problem

In this work, a full core, three-dimensional, multi-group model of VVER-1000 reactor core is developed using specifications of the Schulz benchmark. This paper presents a new 3-D full core solution, and simulates the neutronic behaviour of the VVER-1000 reactor by predicting the system criticality, power distribution, and the neutron flux distribution. Multi-group constants are applied to the COMSOL model to perform neutronics calculations using finite element method with adaptive mesh refinement. The study found that the calculated effective multiplication factor (keff) compares well with the reference value. Furthermore, the fission rates 3D power distributions and axially averaged 2D power distribution are in good agreements with reported reference results. The thermal neutron spectrum is also calculated by the COMSOL model as presented in this paper. This study allows us to validate the COMSOL calculation schemes for VVER-type reactors and to compare our solutions with reference solutions at steady state.