Assessment of passive containment cooling concepts for advanced pressurized water reactors

The containment is the most important barrier against the release of radioactive materials into the environment during accident conditions of nuclear power plants. therefore the development of a reliable containment cooling system is one of key areas in advanced reactor development. In addition to the conventional active systems, several passive containment cooling system (peeS) concepts are developed or proposed for advanced pressurized water reactors (PWRs) to ensure the operability without the need for electric power. This paper presents an overview and comparative assessment on selected pees concepts for advanced PWRs for both steel and concrete containment systems. Major concepts considered are: (a) the spray of water on the outer surface of steel containment from an elevated tank, (b) an external moat for steel containment, (c) a suppression pool for concrete containment. and (d) combination of the internal spray and internal or external condensers for concrete containment. Emphasis is given to the heal removal principles, required heat transfer area. system complexity and operational reliability