A New Strategy for In-Service Inspection of Nuclear Piping Considering Piping Failure Frequency

Abstract:

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The current in-service inspection (ISI) strategy for the nuclear piping in many countries consists of both the code requirements such as ASME B & PV Code Sec. XI and the country-specific regulatory requirements, so called as the enhanced ISI. The enhanced ISI reflects the operating experience of piping failure, while the ASME Code Sec. XI requirement is based on random sampling for the inspection points. In this study, a new strategy for ISI of nuclear piping was proposed based on piping failure frequency. This strategy basically reflects the operating experience because the piping failure frequency is based on the piping failure database. The new concept of minimum inspection rate was also introduced in this new ISI strategy. As pilot study, the new ISI strategy was applied to the Class 1 piping system such as reactor coolant system and safety injection system of Ulchin Unit 5 which is the 1,000 MWe Korean Standard PWR. The results from the proposed new strategy were compared to those from the ASME Code Sec. XI. The results show that the new ISI strategy reasonably reflects the operating experience. The results also show that the concept of the minimum inspection rate can compensate the unbalance in the number of inspection points between the very large differences in the piping failure frequency.

Info:

Periodical:

Key Engineering Materials (Volumes 353-358)

Edited by:

Yu Zhou, Shan-Tung Tu and Xishan Xie

Pages:

2088-2091

Citation:

S. Y. Choi and Y. H. Choi, "A New Strategy for In-Service Inspection of Nuclear Piping Considering Piping Failure Frequency", Key Engineering Materials, Vols. 353-358, pp. 2088-2091, 2007

Online since:

September 2007

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$38.00

[1] American Society of Mechanical Engineer, ASME Boiler and Pressure Vessel Code Sec. XI, Rules for In-Service Inspection of Nuclear Power Plant Components, ASME Code Sec. XI (1998).

DOI: https://doi.org/10.1115/1.859872.ch29

[2] USNRC, Pipe Cracking Experience in LWR, NUREG-0679 (1980).

[3] USNRC, Investigation and Evaluation of Cracking Incidents in Piping in PWR, NUREG-0691 (1980).

[4] USNRC, Erosion/Corrosion-Induced Pipe Wall Thinning in US NPPs, NUREG-1344 (1989).

[5] EPRI, Nuclear Reactor Piping Failures at US Commercial LWRs: 1961 - 1997, EPRI TR-110102, (1998).

[6] SKI, SKI Database: Reliability of Piping System Components (1997).

[7] OECD/NEA, OPDE Database (ver. 2006), OECD Piping Failure Data Exchange (OPDE) Project (2006).

[8] Ulchin Unit 5, Weld Count Database, Korea Hydro & Nuclear Power Company (2003).

[9] Korea's Ministry of Science and Technology, The regulatory guideline of In-Service Inspection for the Nuclear Components, MOST Notice 2004-13 (2004).

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