Reliability analysis of the INEL site power system using fault trees and the IRRAS-PC computer code

The Integrated Reliability and Risk Analysis System Personal Computer Version 2·0 computer code was used in a reliability analysis of the INEL Site Power System. This code was developed at the Idaho National Engineering Laboratory (INEL) as a state-of-the-art microcomputer-based probabilistic risk assessment (PRA) model development and analysis tool for the US Nuclear Regulatory Commission. IRRAS provided an efficient means for the development of a detailed and accurate fault tree model to: (a) identify the dominant causes of power outages on the site; (b) compare the performance of the system using both site-specific data and generic data; and (c) perform a sensitivity study to determine the effects of equipment unavailability caused by the ongoing preventative maintenance (PM) program.