Three dimensional neutronic/thermal-hydraulic coupled simulation of MSR in steady state condition

Highlights: • Developed a three dimensional coupled code for MSR. • Investigated the neutron distribution and thermal-hydraulic characters of the core under steady state condition. • Analyzed the influence of inlet temperature and inlet velocity to thermal-hydraulics characteristics of the reactor. - Abstract: MSR (molten salt reactor) uses liquid molten salt as the coolant and fuel solvent, making it the only liquid reactor among the six generation IV reactor types. As a liquid reactor the physical properties of the reactor are significantly influenced by the fuel salt flow therefore conventional analysis methods applied in solid fuel reactors are not applicable for this type of reactors. The present work developed a three dimensional neutronic/thermal-hydraulic coupled code and applied it to investigate the thermal-hydraulic characteristics of the core in steady state condition based on neutron diffusion theory and numerical heat transfer. The code consists of two group neutron diffusion equations for fast and thermal neutron fluxes and six group balance equations for delayed neutron precursors. The temperature distribution, neutron fluxes and delayed neutron precursors distribution of the core in steady state conditions was studied, and the result analyzed when inlet temperature and velocity were changed. From simulation it was found that the inlet temperature has little influence to neutron distribution however inlet velocity affects the delayed neutron distribution in steady state condition. The results provide some valuable information in design and research of this kind of reactor