Simulation study on HPR1000-based suppressive containment system under typical accidents

Abstract

Studying the typical accidents of nuclear power plant is the basis of nuclear power plant design. In a previous study, our research team proposed a suppression containment system based on the HPR1000 and discussed its performance under the Large-Break Loss-Of-Coolant Accident (LBLOCA) scenario. During the LBLOCA, the activation of the Passive Safety Injection System (PSIS) ensures the core integrity. However, the effectiveness of the Passive Cavity Injection and cooling System (PCIS) in dealing with the extreme accident condition is not adequately confirmed and analyzed. In addition, the rapid depressurization of the Reactor Pressure Vessel (RPV) under LBLOCA does not allow for a full verification of the fit between the PSIS and the Automatic Depressurization System (ADS). Hence, this paper examines the response of the HPR1000-based suppressive containment system in the event of the Small-Break Loss-Of-Coolant Accident (SBLOCA) and the Station Blackout (SBO). We employ the accident analysis procedure, with a specific focus on the thermo-hydraulic evaluation of the PCIS, the PSIS and the ADS. The results show that, the HPR1000-based suppressive containment system has the ability to handle the SBLOCA and the SBO. The PSIS and ADS work together to effectively inject water into the reactor core during the SBLOCA. The start-stop logic setting of the system is reasonable and effective, ensuring long-term cooling of the reactor core. During SBO condition, PCIS effectively achieves rapid cooling of the lower head, ensuring that the peak temperatures do not exceed 600 K. This prevents the lower head from experiencing failure due to high temperatures. Furthermore, the maximum pressure within the containment is a mere 324 kPa, much below the design pressure of 520 kPa. This guarantees that the containment pressure remains within an acceptable range throughout the whole accident.