ML21322A099

Final Request for Additional Information Set 5 - North Anna SLRA Safety Review (EPID No. L-2020-SLR-0000) - Enclosure

ML21322A099
Person / Time
Site:	North Anna
Issue date:	11/18/2021
From:	NRC/NRR/DNRL/NLRP
To:
James L, NRR/DNRL/NLRP, 301-415-3306
Shared Package
ML21322A095	List: ML21322A096 ML21322A099
References
EPID L-2020-SLR-0000
Download: ML21322A099 (2)

Text

NORTH ANNA POWER STATION, UNITS 1 AND 2 (NAPS)

SUBSEQUENT LICENSE RENEWAL APPLICATION (SLRA)

REQUESTS FOR ADDITIONAL INFORMATION (RAIS)

SAFETY - SET 5

1. Buried and Underground Piping and Tanks, AMP XI.M41

Regulatory Basis: Title 10 of the Code of Federal Regulations (10 CFR) Section 54.21(a)(3) requires an applicant to demonstrate that, for components withi n the scope of license renewal, the effects of aging will be adequately managed to maintain the components intended function(s) consistent with the current licensing basis for the period of extended operation. One of the findings that the Nuclear Regulatory Commission (NRC) st aff must make to issue a renewed license (10 CFR 54.29(a)) is that actions have been ide ntified and have been or will be taken with respect to managing the effects of aging during the period of extended operation on the functionality of components that have been identified to re quire review under 10 CFR 54.21, such that there is reasonable assurance that the activities aut horized by the renewed license will continue to be conducted in accordance with the current li censing basis. To complete its review and enable formulation of a finding under 10 CFR 54.29(a ), the staff is requesting additional information regarding the matters described below.

Background:

As required by 10 CFR 54.21(d), each [subsequent] license renewal application (SLRA) must include a final safety analysis report (FSAR) suppl ement containing a summary description of the programs and activities determined by 10 CFR 54.21(a) for managing the effects of aging. In its discussions about FSAR supplements, N RC Standard Review Plan for Subsequent License Renewal (SRP-SLR), Standard Review Plan for Review of Subsequent License Renewal Applications for Nuclear Power Plants, (NUREG-2192, Revision 0, July 2017)

(ADAMS Accession No. ML17187A204) Section 3.3.2.5 notes that t he FSAR supplement description should be sufficiently comprehensive such that late r changes to the program can be controlled by 10 CFR 50.59 Changes, Tests, and Experiments. The SRP-SLR also notes that the program description should include any future aging managem ent activities including enhancements and commitments and contain the bases for determin ing that aging effects will be managed. The SRP-SLR further notes that the type of informa tion to be included is provided in NUREG-2191, Revision 0, Generic Aging Lessons Learned for S ubsequent License Renewal (GALL-SLR) Report, dated July 2017 (ADAMS Accession No. ML17187A031),

Table XI-01, FSAR Supplement Summaries for GALL-SLR Report Cha pter XI Aging Management Programs [AMP].

As amended by Supplement 4 to the SLRA (letter dated August 26, 2021, ADAMS Accession No. ML21238A297), Dominion Energy included extensive changes to the program description in SLRA Section B2.1.27, Buried and Underground Piping and Tanks. Supplement 4 adds a new Enhancement (No. 6) to reflect the deletion of jockey pump moni toring as the basis for not performing excavated direct visual inspection of the buried gra y cast iron fire main piping. The new enhancement describes the performance of nondestructive exa minations (i.e., magnetic particle and radiographic testing) of the excavated piping, and destructive examinations of any identified bounding cracks, with engineering evaluations of cra ck growth, and flaw stability to address cracking due to cyclic loading. Supplement 4 also modi fies Enhancement No. 5 to the Buried and Underground Piping and Tanks program to provide for destructive examinations of the excavated gray cast iron pipe as given in GALL-SLR AMP XI.M 33, Selective Leaching.

Supplement 4 to the application also modified SLRA Section A1, Summary Description of Aging Management Programs, and SLRA Section A1.27, Buried an d Underground Piping and Tanks, by adding the sentence: The program will also manage cracking due to cyclic loading in buried gray cast iron fire protection piping that is lined w ith a cementitious coating. A previous supplement had deleted the discussion about monitoring jockey pump activity in lieu of performing visual inspections of buried fire protection system components. The staff notes that Supplement 4 also modified SLRA Table A4.0-1, Subsequent Licen se Renewal Commitments, Item 27 to describe the commitments to revise procedures for En hancements No. 5 and No.6.

As documented in the NRCs Determination of Acceptability and S ufficiency for Docketing associated with the SLRA (letter dated October 13, 2020, ADAMS Accession No. ML20258A284), the GALL-SLR Report does not address cracking due to cyclic loading for buried gray cast iron piping. Dominion recognized this aspect when it eventually cited an aging management review item with generic note H (indicating the agin g affect was not in the GALL-SLR Report) for cracking due to cyclic loading that will b e managed by the Buried and Underground Piping and Tanks program.

Because the aging effect for the given material and environment combination is not addressed in the GALL-SLR Report, the FSAR program description in GALL-SL R Table XI-01 for the Buried and Underground Piping and Tanks AMP would not be suffic ient. The staff notes that the SLRA did not initially address cracking due to cyclic loadi ng and after substantially enhancing the Buried and Underground Piping and Tank program on ly a single sentence (noted above) was added to the FSAR program description. The staff al so notes that although the table with subsequent license renewal commitments includes a de scription of the programs enhancements, once commitments (e.g., to revise procedures) hav e been completed, they can, and have been deleted from the commitment table.

RAI 4.7.6-1

Issue: In order to ensure that changes to the program, which c ould decrease the overall effectiveness of the program to manage the effects of aging, wi ll receive appropriate review by a licensee, the FSAR supplement s hould be sufficiently comprehens ive. The FSAR supplement in SLRA Section A1.27, Buried and Underground Piping and Tanks, appears to lack a sufficient description of the activities for managing cracking due to cyclic loading to provide appropriate administrative and regulatory controls for the prog ram. The current program includes specific nondestructive and destructive inspections of excavated gray cast iron piping and relatively unique engineering evaluations of crack growth a nd flaw stability in a brittle material that are not described in the current FSAR supplement. In addition, specific activities for managing the loss of material due to selective leaching are being performed as part of the Buried and Underground Piping and Tanks program; however, these activities are not referenced or otherwise noted in SLRA Section A1.21, Selective Leaching. The staff cannot complete its review of the above FSAR supplements without addit ional information.

Request: Provide additional information that either: (a) expl ains how the current FSAR supplement descriptions in SLRA Section A1.27 for of the Buried and Underground Piping and Tanks program and SLRA Section A1.21 for the Selective Leaching program will provide appropriate administrative and regulatory controls to ensure th at any future changes to the programs will not decrease their overall effectiveness to manag e the effects of aging, or (b) modifies the associated FSAR supplements to include a more detailed description of the programs and aging management activities.