Development of a PCCS module in the ATHROC for simulation of passive containment cooling system

摘要

Advanced reactors, such as HPR1000 and VVER1200, have adopted passive containment cooling systems (PCCSs) to maintain containment integrity under accident conditions. In order to meet the requirements of behavior and effect analysis of PCCS in containment, a multi-compartment containment code ATHROC was further developed by adding PCCS module. Then the code benchmarking based on RELAP5 MOD3.4 and the experimental validations based on PANGU experiment were conducted. Finally, the thermo-hydraulic analysis of the containment of CPR1000 (a gigawatt pressurized water reactor) with PCCSs during LOCA was carried out using ATHROC. The results show that although two sets of PCCS are able to inhibit the containment pressure rise under LBLOCA with the failure of CSP (Containment Spray system), the coolant in water tanks evaporates too fast to meet the requirement of a 72-h passive heat removal from the containment. This study newly proposed a validated and benchmarked multi-compartment containment code called ATHROC for thermo-hydraulic analysis of a containment with PCCS in single-phase and two-phase states. Both containment and PCCS transients can be captured by ATHROC. It is demonstrated that the ATHROC code could offer good practicability and adaptability for capturing both containment and PCCS transients.