Failure mode and effect analysis of Emergency Diesel Generation System of a typical PWR

The external electric power lost (blackout incident), on commercial pressurized water reactors (PWR), generates an automatic reactor shutdown. When this occurs, the Emergency Diesel Generation System (EDG) is demanded in order to maintain a set of safety plant basic functions. So, the external blackout event leads to EDG real demand. Due to EDG importance to nuclear plant safety, this paper presents an EDG Angra II failure mode and effects analysis (FMEA). This study also uses the risk priority number (RPN) concept. The RPN is constituted by three parameters: probabilities of occurrence (O), event severity level (S) and probability of failure non-detection (D). The use of the RPN permits, in addition to the traditional FMEA results, a ranking of the system failure modes. The obtained results demonstrated the potential of this technique to application on future risk studies. (author)