ML23160A151

25 - Industry - Industry Perspectives on ASME III and XI Pre-Service Inspection

ML23160A151
Person / Time
Site:	Nuclear Energy Institute
Issue date:	06/15/2023
From:	Basso T, Mccracken S, Ossmann J, Park G Electric Power Research Institute, Iddeal Solutions LLC, Nuclear Energy Institute, Westinghouse
To:	Ali Rezai NRC/NRR/DNRL/NPHP
References
Download: ML23160A151 (1)

Text

Industry Perspectives on ASME III and XI Pre-Service Inspection (PSI)

NRC-Industry Technical Exchange Public Meeting June 15, 2023 Janis Ossmann - Westinghouse, Gary Park - Iddeal Solutions, Steve McCracken - EPRI, Thomas Basso - NEI

Introduction

• Industry response to NRC concerns with potential changes to ASME Section III and XI regarding Preservice Inspections

- Industry Perspective on Section III PSI

- Industry Perspective on Section XI PSI

- Summary and Conclusion

Industry Perspective on Section III PSI

• Preservice Inspection in Section III is not a construction code acceptance examination.

• PSI is performed ONLY to provide a baseline for future Section XI Inservice Inspection.

- Section XI requires that PSI be completed prior to initial plant startup.

• PSI was first added to Section III in the 1997 addendum to the 1995 edition of Section III

• In some cases, the PSI is performed in a fabrication shop, but in many cases the PSI is performed by the Owner at site after installation is complete

Industry Perspective on Section III PSI

• Current requirement to complete PSI prior to N-5 means the N-certificate holder, who may not be performing the PSI, is held up issuing N-5 due to PSI not in their control

• Code Case N-907 and proposed code change (Record 20-82) allows PSI to be performed after N-5 but before N-3 data report

- PSI is still performed before components are placed into commercial service.

• Section III is NOT eliminating PSI it is only changing the timing as to when it can be completed to provide flexibility during construction

• Record 20-82 also adds requirements for Owners Design Specification to specify responsible parties for performing each PSI and reporting/documentation

Industry Perspective on Section XI PSI

• PSI is a preoperational examination performed to provide a baseline for subsequent ISI.

• PSI must be performed prior to placing the system in operation.

• ASME XI IWB-3131(c) only requires the results of ISI be compared with PSI and previous ISI examinations and differences recorded.

• To maintain the baseline any repair/replacement activity that affects a previous PSI/ISI examination requires a new baseline PSI.

Original Intent of Section XI PSI

• Of primary concern when developing Section XI acceptance standards in the early 1970s was to avoid conflicts with Section III requirements.

- . a flaw found by a Section XI examination that is determined to have been present in original construction and is of a size and type that exceeds the acceptance standard of the original Construction Code, but is acceptable under the acceptance standards of Section XI, the flaw is not required to be removed or repaired. [1]

• Any indications found under PSI that meet the original Construction Code, should be acceptable using evaluation techniques such as fracture mechanics.

[1] Companion Guide to the ASME Boiler & Pressure Vessel Code, 2009. Vol. 2, 3rd Ed., Chap. 26, p. 238

Section III Acceptance Criteria

• Acceptance criteria based on appropriate quality and workmanship standards.

• Intended to detect weld fabrication type flaws that do not meet the specified level of quality and workmanship.

- Flaws characterized as a crack, lack-of-fusion, lack-of-penetration of any size are rejectable.

- Volumetric flaws, such as non-metallic inclusions (slag) or porosity, that exceed a specified size are rejectable.

• Not based on detailed structural integrity or fracture mechanics.

Current Section XI Acceptance Criteria

• Fracture mechanics-based acceptance standards.

• Conservative assumption that all observed indications are crack-like defects and treated as planar flaws with depth a and length l.

- The treatment of all indications as planar flaws was adopted by Section XI to assure a high degree of conservatism although defects, other than cracks, were recognized as relatively unimportant. [2]

[2] EPRI Report NP-1406-SR

PSI Acceptance Standards

• PSI acceptance standards for piping welds based on fracture mechanics were added in the 1974 Edition of Section XI. [3,4]

- An important consideration at the time was the variability in capability of UT techniques to accurately locate and size flaws in piping welds.

- The allowable acceptance standards for PSI were intentionally established at a more restrictive level to assure that the results of the ISI examinations would not be unacceptably biased by the variability of UT examination of piping, particularly when results are compared to PSI. [4]

• Much improved UT techniques and Appendix VIII performance demonstration requirements have all but eliminated this concern of the early 1970s.

[3] EPRI Report NP-1406-SR, Special Report, May 1980, pp. I-19.

[4] Chockie, L.J. and MacCary, R.R. Extended Rules of the 1974 ASME Section XI Code, Inservice Inspection of Nuclear Power Plant Components, IMechE 1976, pp. 91-99; C206/76

Section XI Proposed Changes

• The original reference to a Preservice Examination was identified as Preoperational Examination and was only used to identify the condition of items prior to putting them into service.

• Over time preservice examination evolved into a second acceptance examination even though the item was already acceptable to the construction code.

Section XI Proposed Changes

• As items have already been accepted by the Construction Code, the PSI Acceptance Standards are no longer required and are proposed to be deleted.

• This change reestablishes the original intent that PSI is for baseline only.

Summary and Conclusion

• ASME III changes provide more flexibility for when PSI can be performed during construction and shifts responsibility more to the Owner

• ASME XI proposed changes reestablish the original intent of PSI

• No code changes eliminate PSI

Backup Slides Code Case N-907: Passed and published by ASME Rules for Performance of Preservice Inspection (PSI) During Section III Construction Inquiry: What rules may be used for performance of preservice inspection (PSI) during Section III Construction if the examinations are not performed prior to completion of the N-5 data report, as required by NB-5281(a).

Reply: It is the opinion of the Committee that PSI required to be completed by NB-5281(a) may be completed after completion of the N-5 Data Report but prior to the Owners filing of the N-3 Data Report under the following conditions:

a) This Case number and revision shall be listed on the applicable N-5 Data Report.

b) The Authorized Nuclear Inspector (ANI) signing the N-3 Data Report is required to confirm all PSI required by NCA-3252(c) is complete.

c) This Code Case number and revision shall be listed on the applicable N-3 Owners Data Report in the Remarks section.

Changes to both

• NCA-3211.19 Record 20-82 (Out Provisions of the for Section III Design Specifications and Standards

• NB-5280 Committee Ballot) PRESERVICE EXAMINATION OR MANDE

Record 20-82 changes to NCA-3211.19

Record 20-82 changes to NB-5280