Coupled Neutron Dynamic and Thermal Hydraulic Models of the HTR Simulator

Along with the design and construction of the high temperature reactor pebble bed module (HTR-PM), the engineering simulator system (ESS) has been accomplished to deal with the key techniques of the HTR simulator. In our previous papers, the three dimensional space-time neutron dynamics and the thermal hydraulic modeling of the HTR reactor core were introduced. In this paper, we concentrated on the detailed coupling techniques of the neutron dynamic and thermal hydraulic models, which was one of the most important assurances to the dynamic simulations of the HTR-PM. The mechanism of minus temperature feedback effect of the HTR was introduced by the materials participated in the coupling calculations, as well as those parameters being transferred. In parallel calculations, the neutron dynamics and thermal hydraulics were coupled by exchanging the power density and the temperature in fuels, moderates, reflectors and so on. With complete reactor core model, the coupling calculations of the neutron dynamics and thermal hydraulics were tested in many static and dynamic cases to show good performances. Based on that model ability, the ESS can simulate the start-up, shut-down and several accidents for the whole nuclear power plant.