Simulation of maintenance effectiveness in repairable systems to control risk due to aging
Time- or cyclic-dependent degradation (aging) processes such as wear, corrosion, and fatigue have caused problems at some of the US reactors. This paper presents a methodology to develop optimum maintenance programs that would help control aging-related risks. The study addresses the predictive behavior of systems containing repairable components as represented in current probabilistic risk assessment (PRA) models. The system model chosen for the study is the Draft NUREG-1150 Surry auxiliary feedwater (AFW) system. The simulation results provide an indication of the periodicity at which the aging effects must be corrected to maintain the system failure probability at or below the calculated levels. When maintenance is allowed to periodically correct the effects of aging, the system failure probability is essentially constant over 60 years. Also, results indicate that the system unreliability is not linearly related to the periodicity of aging correction. Therefore, a plant maintenance program would have significant latitude in developing the desired maintenance periodicity limits. In fact, the calculated values for component maintenance periodicity are of such time intervals that aging control can easily be accommodated by a plant maintenance program. 5 refs., 4 figs., 3 tabs.
- Research Organization:
- EG and G Idaho, Inc., Idaho Falls (USA)
- DOE Contract Number:
- AC07-76ID01570
- OSTI ID:
- 6796864
- Report Number(s):
- EGG-M-88101; CONF-880824-2; ON: DE89005281
- Resource Relation:
- Conference: International nuclear power plant aging symposium, Bethesda, MD, USA, 30 Aug 1988; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NUCLEAR POWER PLANTS
AGING
AUXILIARY SYSTEMS
CORROSION
FAILURES
FATIGUE
FEEDWATER
MAINTENANCE
REACTOR COMPONENTS
REACTOR SAFETY
RELIABILITY
RISK ASSESSMENT
SURRY-1 REACTOR
SURRY-2 REACTOR
SURRY-3 REACTOR
SURRY-4 REACTOR
WEAR
CHEMICAL REACTIONS
ENRICHED URANIUM REACTORS
HYDROGEN COMPOUNDS
MECHANICAL PROPERTIES
NUCLEAR FACILITIES
OXYGEN COMPOUNDS
POWER PLANTS
POWER REACTORS
PWR TYPE REACTORS
REACTORS
SAFETY
THERMAL POWER PLANTS
THERMAL REACTORS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
220200 - Nuclear Reactor Technology- Components & Accessories