Automatic tools to assist probabilistic risk assessment engineers; Fault tree creation using artificial intelligence technology

Kondo, Yuki; Futagami, Satoshi ; Kurisaka, Kenichi ; Yamano, Hidemasa  

Utilization field of probabilistic risk assessment (PRA) has been widened. Nevertheless, PRA engineers have been needed to endure the laborious task to read and understand a huge amount of design documents and utilize the information obtained. One of key methods for solving these issues is to use artificial intelligence (AI) technology. Therefore, the authors have conducted a three-year program to develop an automatic fault tree (FT) creation tool using AI technology for the aim of enabling any engineer to easily perform PRA with the same quality as a conventional approach. The FT creation tool was developed for creating FT from the design documents such as paper source-based piping and instrumentation diagram, single-line diagram, etc. The automatic tools are implemented for FT creation process using AI technology and rule based automatic programs with annotation graphical user interface tool. A three-year program included three steps of development. As a first step, the authors prototyped the tools for the front-line system FT creation with component level of detail. As a second step, this tool was updated to adopt failure mode level FT creation for frontline and support system. As a final step, this tool was updated to include two functions. One was updated to adopt signal systems. This function expansion also enables to generate signal system FT from a multi-page design document. The other one is the logical data construction function to integrate FT, considering the functional dependencies between the frontline system and the support system. This three-year program was finished for now. Presenter will present overall development program and progress of FT creation tool development.