This paper describes industry programs to manage structural degradation and to justify continued operation of nuclear components when unexpected degradation has been encountered due to design materials and/or operational problems. Other issues have been related to operation of components beyond their original design life in cases where there is no evidence of fatigue crack initiation or other forms of structural degradation. Data from plant operating experience have been applied in combination with inservice inspections and degradation management programs to ensure that the degradation mechanisms do not adversely impact plant safety. Probabilistic fracture mechanics calculations are presented to demonstrate how component failure probabilities can be managed through augmented inservice inspection programs.

S. H.
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Statistics of Pressure Vessel and Piping Failures
ASME J. Pressure Vessel Technol.
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S. H.
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Failure Mechanisms in Nuclear Power Plant Piping Systems
ASME J. Pressure Vessel Technol.
, pp.
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