Looking out for common cause failures
Common cause failures (CCFs) have been a continuing concern in nuclear plant operation; first, because they do occasionally occur, and second, because probabilistic risk assessment studies indicate that CCFs are potentially significant risk contributors due to the success of defenses against multiple, independent failures. A comprehensive Electric Power Research Institute, (EPRI) study of CCFs has (a) developed a well-defined classification system for analyzing fault events, and (b) studied licensee event report data for the auxiliary feedwater system (AFWS) and reactor protection system (RPS) using this classification system and analysis of root cause, failure modes, detection methods, corrective actions, and defensive measures. In this work, the confusion generally encountered with the definition of CCF has been resolved by directing attention to branched events - i.e., any event in which a root or component cause resulted in concurrent, multiple unavailabilities (either physical failure or functional unavailability). The current emphasis in the EPRI project is on defensive measures against branched events. This paper discusses some preliminary project results.
- OSTI ID:
- 7179449
- Report Number(s):
- CONF-861102-
- Journal Information:
- Trans. Am. Nucl. Soc.; (United States), Journal Name: Trans. Am. Nucl. Soc.; (United States) Vol. 53; ISSN TANSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
210800* -- Nuclear Power Plants-- Economics
AVAILABILITY
CONTROL
COST
DESIGN
EFFICIENCY
EPRI
FAILURE MODE ANALYSIS
FAILURES
FAULT TREE ANALYSIS
FEEDWATER
HYDROGEN COMPOUNDS
MAINTENANCE
MANAGEMENT
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
OPERATION
OXYGEN COMPOUNDS
POWER PLANTS
PROBABILITY
QUALITY CONTROL
REACTOR COMPONENTS
REACTOR MAINTENANCE
REACTOR OPERATION
REACTOR PROTECTION SYSTEMS
RISK ASSESSMENT
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
THERMAL POWER PLANTS
TRAINING
WATER