Verification Method of Software for Microprocessor-Based Protection System of Nuclear Power Plants

This paper proposes a new concept for efficient verification of software for the protection systems of nuclear power plants. In this idea, all possible input combinations are applied to each module comprising the software and the module responses are compared with their correct responses which are provided beforehand. To realize the concept, algorithms have been developed for observing module responses through an external tester and for generating a quasi minimal test pattern set capable of testing all modules. This approach remarkably reduces the number of required test input combinations in comparison with that of the combinations without observation of module outputs. In addition, most software errors are expected to be uncovered more efficiently with less effort and time.