ML18131A223

Prairie and Monticello - Response to Request for Additional Information Regarding Proposed Alternative to Utilize Code Case N-513-4, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Di

ML18131A223
Person / Time
Site:	Monticello, Prairie Island
Issue date:	05/11/2018
From:	Murphy M Northern States Power Co, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EPID L-2017-LLR-0143, L-XE-18-008
Download: ML18131A223 (3)

Text

414 Nicollet Mall Minneapolis, MN 55401 fl Xcel Energy*

RESPONSIBLE BY NATURE 800.895.4999 xcelenergy.com May 11, 2018 L-XE-18-008 10 CFR 50.55a ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant, Monticello Nuclear Generating Plant Units 1 and 2 Docket 50-263 Dockets 50-282 and 50-306 Renewed Facility Operating License Renewed Facility Operating License Nos. No. DPR-22 DPR-42 and DPR-60 Response to Request for Additional Information Regarding Proposed Alternative to Utilize Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1" (EPID: L-2017-LLR-0143)

References:

1) Email from the NRC to NSPM, DRAFT Request for Additional Information RE: Monticello and Prairie Island Relief Request to Adopt Code Case N-513-4, dated April 16, 2018.

2) Letter from NSPM to the NRC, Proposed Alternative to Utilize Code Case N-513-4, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1, dated November 29, 2017. (ADAMS Accession Number ML17333A775)

Northern States Power Company, a Minnesota Corporation (NSPM), doing business as Xcel Energy, provides the enclosed responses to requests for additional information (Reference 1) regarding NSPMs request to use ASME Code Case N-513-4, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1 (Reference 2).

Document Control Desk Page 2 Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

~~~u*t)-

Director, Nuclear Licensing and Regulatory Services Northern States Power Company- Minnesota Enclosure cc: Administrator, Region Ill, USNRC Project Manager, Monticello, USNRC Project Manager, Prairie Island, USNRC Resident Inspector, Monticello, USNRC Resident Inspector, Prairie Island, USNRC

L-XE-18-008 NSPM Enclosure Response to Request for Additional Information Regarding Proposed Alternative to Utilize Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1" (EPID: L-2017-LLR-0143)

RAI-1. Section 5 Proposed Alternative and Basis for Use of the proposed alternative states

[t]he critical leakage rate is determined as the highest leakage rate that can be tolerated and may be based on the allowable loss of inventory or the maximum leakage that can be tolerated relative to room flooding, among others. Confirm that the critical leakage rate will be based on the limiting condition. For example, if the maximum allowed flooding is 50 gallons per minute (gpm) and the maximum allowed loss of inventory is 25 gpm, 25 gpm is the critical leakage rate.

Response

The critical leakage rate will be based on the most limiting condition, whether it is due to flooding, inventory loss, or some other limiting flow rate.

RAI-2. Page 2 of the November 29, 2017 letter indicates that there are three Enclosures to the letter. However, the NRC staff notes that Enclosures 2 and 3 are not attached to the letter. Address the missing enclosures.

Response

The listing of Enclosures 2 and 3 was made in error. NSPM intended to refer to Attachments 3 and 4 of Reference 1 (as discussed in response to RAI-3) respectively.

RAI-3. Page 3 of the Enclosure to the November 29, 2017 letter states, [s]ignificant changes in Code Case N-513-4 when compared to NRC approved Code Case N-513-3 are discussed in Reference 1, Attachment 4, Technical Basis for Proposed Fourth Revision to ASME Code Case N-513." However, no Reference Section is provided in Enclosure 1 and the Title and other pertinent information needed to identify Reference 1 has not been provided. Provide the appropriate information necessary to identify Reference 1.

Response

The reference was inadvertently omitted from the submittal. Reference 1 refers to a letter from Exelon Generation Company, LLC to the NRC, Proposed Alternative to Utilize Code Case N-513-4, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1," dated January 28, 2016. (ADAMS Accession Number ML16029A003)

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