Survey of operating experience to identify structural degradation of nuclear power plant components

Abstract

An assessment was performed by the Nuclear Operations Analysis Center (NOAC) staff at Oak Ridge National Laboratory of the information available from operation of United States nuclear power plants in their Licensee Event Reports (LERs) which is pertinent to identifying failures due to age-related degradation. LERs from commercial power plants submitted from 1969 to 1982 were surveyed, yielding 3098 events that were considered to be age-related failures. Wear, corrosion, fatigue, vibration, stress corrosion, and erosion were identified as the structural failure cause mechanisms in over half of the events. The study contains data on failed components, the age-related failure mechanisms responsible, the severity of the failures, and the failure detection methods of failures from possible age-related causes.