Analyses of the impact of inservice inspection using a piping reliability model

Technical Report · Sun Jul 01 04:00:00 EDT 1984

DOI:https://doi.org/10.2172/6624734· OSTI ID:6624734

Simonen, F A; Woo, H H

This report presents the results of a study of the impact of inservice inspection (ISI) programs on the reliability of specific nuclear piping systems that have actually failed in service. Two major factors are considered in the ISI programs: one is the capability of detecting flaws; the other is the frequency of performing ISI. A probabilistic fracture mechanics model is used to estimate the reliability of two nuclear piping lines over the plant life as functions of the ISI programs. Examples chosen for the study are the PWR feedwater steam generator nozzle cracking incident and the BWR recirculation line safe-end cracking incident. The results show that an effective inservice inspection requires a suitable combination of flaw detection capability and inspection schedule. An augmented inspection schedule is required for piping with fast-growing flaws to ensure that the inspection is done before the flaws reach critical sizes. Also, the elimination of poor inspection teams through training and qualification testing can produce significant benefits to ISI effectiveness.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6624734
• Report Number(s): NUREG/CR-3869; PNL-5149; ON: TI84015972
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100* -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
210200 -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
BWR TYPE REACTORS
ENERGY SYSTEMS
FAILURES
IN-SERVICE INSPECTION
INSPECTION
NOZZLES
PIPES
PWR TYPE REACTORS
REACTORS
RELIABILITY
STEAM SYSTEMS
WATER COOLED REACTORS
WATER MODERATED REACTORS