Development of coupled neutron physics/thermal hydraulics system using OpenMC and RELAP5

Abstract

With the ongoing development in capabilities of computational and modeling tools, feedbacks of thermal hydraulics and neutronics allow us to get improved and economical designs of nuclear reactors, with more realistic and accurate evaluation of the design parameters. This work is aimed to validate various aspects of a benchmark problem for testing the coupling scheme developed by using RELAP5 & OpenMC as thermal hydraulic and neutronic codes respectively, and FORTRAN as the external coupling agent, on the Intel Core i7 processor, Windows system. The benchmark problem consists of a BWR fuel pin divided into axial segments. At each axial mesh normalized power and fuel temperature plus coolant density are computed using OpenMC and RELAP5 respectively. Convergence was checked at each iteration for all the three parameters i.e. coolant density, fuel temperature and normalized power. Converged and stable results were obtained after 7 iterations, in a total time of 1.7hr, with one simulation taking 14.2min. Finally benchmark results are validated.