Use of PRA and economic risk at the plant design stage: An application

When Westinghouse began development of an Advanced PWR in the late 1970's specific objectives were set in order to optimize the plant. These objectives covered both safety and commercial goals, such as reduced plant cost, simplified design and operation, increased availability, reduced radiation exposure. Safety goals were set to resolve NRC licensing issues, to reduce core melt frequency, and to address severe accidents issues. The subject of this paper concentrates on one phase of the development effort, where the design was studied for applications in Japan. A very similar version of the plant, the Westinghouse Advanced PWR, identified as the SP-90, is currently being reviewed by the NRC. This paper briefly mentions the overall design effort, but concentrates on application of PRA methods and economic risk assessment for selection of proposed safety systems. (orig./HSCH)