A verification and validation method and its application to digital safety systems in ABWR nuclear power plants

A verification and validation (V and V) method has been developed and applied to newly developed digital safety systems for the first ABWR plant, Kashiwazaki-Kariwa unit No. 6 of the Tokyo Electric Power Company. This paper describes the method and experience gained from its application. The method was developed on the basis of domestic and foreign standards and guidelines, and covers the more concrete procedures required for actual V and V. The application of problem oriented language (POL) helps make the V and V feasible and reliable. A personal-computer-based automatic test tool for the validation test has been developed and utilized. This tool is used to carry out the pre-defined validation test procedure automatically and produce a test report, and it was found to be effective in reducing the time and manpower required for the validation test. The validation test covers dynamic transient tests in which the response of the digital safety system against the simulated design based transients are tested. The tool enables automatic execution of the dynamic test. (orig.)