3D hexagonal parallel code QuDiff for calculating a fast reactor’s critical parameters

Abstract

Being applicable for high-performance computing systems, a parallel code based on the sequential QuDiff code was developed to calculate the critical assembly of the fast neutron reactor active zone. The multigroup transport equation calculation method was based on V. Ya. Goldin’s quasi-diffusion method. For efficient algorithm construction, it was suggested to use all the possible reactor assembly symmetries for the self-adjustable neutron-nuclear operation mode. MPI was applied as a parallel interface. The domain decomposition method was used. The pipelined parallelization method was applied for the consistent parallelization of the calculation of the quasi-diffusion system of equations and for the calculation of the transport equation. The calculations performed for the 3D active zone model of the BN-800 reactor capable of operating in a self-adjustable neutron-nuclear mode showed that the parallel code QuDiff is highly scalable. The present results can be used in the dynamic numerical simulation of a fast reactor’s active zones.