Research on Transient Analysis Method Based on 3D Neutronic/Thermal-Hydraulic Coupling Calculation

The classic normal operation transient method uses the 0D (point) neutron kinetic model to simulate the reactor core, which has a lower computational accuracy for core state simulation. Besides, the 0D kinetic model cannot simulate the core parameters variation during the transients (such as AO and power distribution). In order to reach a higher computational accuracy and acquire the core parameters variation during transients, a new normal operation transient analysis method based on the 3D neutronic/thermal-hydraulic coupling calculation is proposed in this paper. Thermal-hydraulic code uses the output of neutronic code as input to calculate the variation of thermal-hydraulic parameters and the response of control system, and then, the output of thermal-hydraulic code is feed back to the neutronic code to calculate the core state variation. House load transient is used as an illustrative case in this paper to compare the 3D neutronic/thermal-hydraulic coupling calculation results with the 0D kinetic model calculation results and operation data. According to the result, the 3D neutronic/thermal-hydraulic coupling calculation method is feasible and reasonable, which can simulate realistically the reactor core state variation and the control system response during the transient.