Containment integrity analysis for the (W) advanced AP900

The consequences of accidents that occurred at Three Mile Island and Chernobyl and the lack of interest from utilities in committing to high powered, high maintenance light water reactor designs of the past have motivated the nuclear industry to develop smaller, lower powered, simplified designs. Simplified designs must employ more passive systems that require very low maintenance and rely on the basic laws of nature. These designs must not be limited only to the reactor, but must also include the containment building. The purpose of this paper is to discuss the design concepts and to verify the feasibility of the Westinghouse Passive Containment Cooling System (PCCS) design for a 900 MWe advanced passive reactor design (AP900) by presenting its response to a design basis large break Loss of Coolant Accident (LOCA). The mass and energy releases emanating from the design basis break were developed and a representative containment model was constructed. The COMPACT computer code, which is a multi-node program that solves the complete set of mass, energy and momentum equations, was used to determine the AP900 containment response. The PCCS design concept, the computer model, the analysis inputs, and the results of the study are discussed within this paper. (author). 2 refs., 9 figs