Analysis of Rotor-Seizure-Induced Pressure Rise in a Nuclear Reactor Primary Cooling Loop

Most of existing methods for the safety assessment of the primary cooling loop of nuclear reactors in conditions of reactor coolant pump (RCP) failure (rotor seizure accident) essentially rely on the combination of one-dimensional theory and experience. This study introduces a novel three-dimensional model of the ‘Hualong-1’ (HPR1000) primary loop and uses the method of matching the resistance characteristics of the tube to ensure that the main pump operates at the rated operating condition. In particular, the three-dimensional unsteady numerical calculation of the RCP behavior in the rotor-seizure accident condition is carried out in the framework of the RNG k-ε turbulence model. The related transient pressure surge law and hydraulic load response are obtained accordingly.