Development of plant DiD Risk Monitor system for NPPs by utilizing UML modelling technology

A new risk monitor system is under development which can be applied not only to prevent severe accident in daily operation but also to serve as to mitigate the radiological hazard just after severe accident happens. The system simulates these applied situations, by generating interactions among all actors such as the plant and related people coping with the accident. In this paper, the plant DiD risk monitor is developed utilizing Unified Modeling Language (UML) to model actors' knowledge and express the interactions. Case study to confirm functionality and ability of DiD risk monitor is also introduced by showing examples for Station blackout accident in conventional PWR plant in Japan.