Study on Key Technologies of Passive Containment Heat Removal System for HPR1000

The passive containment heat removal system (PCS) is one of the key passive safety systems of China’s third-generation advanced pressurized water reactor—Hua-long Pressurized Reactor (HPR1000), used to prevent overpressure of large concrete containment under severe accident scenarios. This paper provides an overview of the development of the HPR1000 passive containment heat removal system, including its operating principles and configuration, internal heat exchanger design, feasibility tests, engineering-scale PCS verification tests, comprehensive tests on PCS–containment coupling characteristics, among other key supporting studies. These extensive studies demonstrated that the PCS of HPR1000, which is designed based on flashing-driven open natural circulation and efficient condensation heat transfer theory, can work effectively and ensure the integrity of the containment under various accident scenarios. The system has been applied to Fuqing No. 5 and No. 6 nuclear power units and Zhangzhou No. 1 and No. 2 units of China’s first million-kilowatt third-generation nuclear power HPR1000. It is also applied to K-2/K-3 units of Karachi Nuclear Power Plant in Pakistan.