ML21314A447

Slides for Presubmittial Meeting for Proposed Alternative to Adopt ASME Code Case N-921 to Extend the Inservice Inspection Interval

ML21314A447
Person / Time
Site:	Calvert Cliffs, Dresden, Peach Bottom, Nine Mile Point, Byron, Braidwood, Limerick, Ginna, Clinton, Quad Cities, FitzPatrick, LaSalle
Issue date:	11/10/2021
From:	Rhoades D Exelon Generation Co, Exelon Nuclear
To:	Blake Purnell Plant Licensing Branch III
Purnell B
References
Download: ML21314A447 (12)

Text

Pre-Submittal Meeting for Exelon Relief Request N-921:

ASME Code Case to Extend 120-month Inservice Inspection Interval November 16, 2021

Agenda

• Relief Request

• Code Case

• 10 CFR and ASME References

• Precedent

• Summary/Key Takeaways

• Questions/Comments 2

Relief Request

• Submittal would be a request for alternative under 50.55a(z),

Alternatives to codes and standards requirements

• Exelon intends to implement the ASME Code Case N-921, which extends the inspection interval from 10 to 12 years.

• The proposed alternative would be to extend the Inservice Inspection (ISI) Interval by 2 years as described in the Code Case.

• Goal is to submit the request by the end of 2021.

3

Code Case

• ASME Section XI currently breaks up the 10-year inspections interval into three periods (three/four/three years).

• This Code Case extends the inspection interval from 10 to 12-years, which will allow for an even number of years in each period (four/four/four).

Each inspection interval may be extended or reduced by as much as 1 year.

Plants that are out of service continuously for 6 months or more may extend the interval.

• Under Code Case N-921, the current code rules would essentially be applied to a 12-year inspection interval.

4

Code Case

• This is a marginal extension from a 10-year to 12-year interval which supports a minimum two outages per period if possible.

This will reduce the overall scheduling during the one period that has only one outage under the current scheme.

Supports improved operational strategies such as skip ISI outages and divisional outages.

5

Code Case Inspection Minimum Maximum Period (Years) Examinations Examinations Completed, % Credited, %

[Note (1)] [Note (1)]

4 16 50 8 50 [Note (2)] 75 12 100 100 (1) For IWE, completion percentage applies only to moisture barriers (Examination Category E-A, Item No. E1.32). This requirement does not apply to use of this Case with Editions prior to the 2017 Edition.

(2) If the first period completion percentage for any examination category exceeds 34%,

at least 16% of the required examinations shall be performed in the second period.

6

10 CFR and ASME References

• Exelon has reviewed the following provisions of 10 CFR 50.55a and the ASME Codes:

10 CFR 50.55a(b)(5) 10 CFR 50.55a(g)(4) 10 CFR 50.55a(g)(5)

ASME B&PV Code,Section XI, 2007 Edition, no Addenda, and 2013 Edition:

IWA-2410 - APPLICATION OF CODE EDITION AND ADDENDA IWA-2430(a) through (g) - INSPECTION INTERVALS IWA-2431 - INSPECTION PROGRAM Table IWB-2411-1, IWC-2411-1, IWD-2411-1, IWE-2411-1, and IWF-2410 Inspection Program - These Tables provide the calendar years for each period (3 years, 7 years,10 years).

• Exelon plans to submit a Relief Request based on the precedent on the next slides.

7

Precedent

• NRC approvals of 120-month interval modifications through 50.55a(z):

Indian Point Nuclear Generating Unit No. 3 (July 18, 2018) (ML181938030) 12-month extension Fitzpatrick Nuclear Power Plant (August 4, 2017) (ML17201M289) 8-month extension (IST program)

Limerick Generating Station, Units 1 and 2 (January 24, 2007) (ML063390103)

Reduced the duration of the second ISI interval for LGS Unit 2 by approximately 3 years Arkansas Nuclear One, Unit 1 (August 6, 2007) (ML071730556)

Extend its third 10-year ISI interval by approximately 6 months beyond the 1-year extension (18 months)

Point Beach Nuclear Power Plants, Units 1 and 2 (June 18, 2001)

(ML011570015)

Interval shortened 3 months.

8

Precedent

• NRC approvals of 120-month interval modifications through 50.55a(z) (continued):

McGuire Nuclear Station, Unit 1 (August 21, 2020) (ML20230A205)

Extended Code of Record for first period (3-year extension) of successive interval SER cited 10 CFR 50.55a(g)(4)(ii)

Arkansas Nuclear One, Unit 2 (June 11, 2019) (ML19156A400)

Extended the Code of Record for 10 years Maintained 2007/2008 Edition as part of the new update Did not update to 2013 Edition SER cited 10 CFR 50.55a(g)(4)(ii)

Surry Power Station, Units 1 and 2 (April 29, 2013) (ML13100A049)

Extended the Code of Record for 10 years Maintained 2004 Edition as part of the new update Did not update to 2007/2008 Edition SER cited 10 CFR 50.55a(g)(4) 9

Precedent

• NRC approvals of 120-month interval modifications through 50.55a(z)

(continued):

McGuire Nuclear Station, Unit 1 (March 3, 2011) (ML110410172)

Extended Code of Record for approximately 3 years SER cited 10 CFR 0.55a(g)(4)(ii) 10

Summary/Key Takeaways

• Exelon intends to implement the ASME Code Case N-921, which extends the inspection interval from 10 to 12 years.

• Goal is to submit the request by the end of 2021.

• Under Code Case N-921, the current code rules would essentially be applied to a 12-year inspection interval.

• Precedent for extensions longer than 2 years.

11

QUESTIONS/COMMENTS 12