ML19324F851

Long-Term Replacement Steam Dryer Inspection Plan

ML19324F851
Person / Time
Site:	Monticello
Issue date:	11/20/2019
From:	Church C Northern States Power Company, Minnesota, Xcel Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-MT-19-04 7
Download: ML19324F851 (5)

Text

Xcel Energy 2807 West County Road 75 RESPONSIBLE BY NATURE Monticello, MN 55362 November 20, 2019 L-MT-19-04 7 License Condition 2.C.15(h)

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket No. 50-263 Renewed Facility Operating License No. DPR-22 Monticello Nuclear Generating Plant (MNGP) Long-Term Replacement Steam Dryer Inspection Plan Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby submits the proposed long-term inspection plan for the MNGP Replacement Steam Dryer for NRC review and approval. The plan was developed using the inspection results from the two refueling outages after reaching extended power uprate (EPU) conditions and industry operating experience.

The enclosed inspection plan is being submitted pursuant to the MNGP Renewed Facility Operating License, License Condition 2.C.15(h), which requires that NSPM, at the end of the second refueling outage following the implementation of the EPU, must submit a long-term steam dryer inspection plan based on industry operating experience, along with the baseline inspection results, for NRC review and approval.

Please contact Mr. Jeff Kivi at (612) 330-5788 or Jeffrey.Kivi@xenuclear.com if there are any questions or if additional information is needed.

Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

Document Control Desk Page 2 Christopher R. Church Site Vice President, Monticello Nuclear Generating Plant Northern States Power Company - Minnesota Enclosure cc: Administrator, Region Ill, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC

L-MT-19-047 NSPM Enclosure ENCLOSURE MONTICELLO NUCLEAR GENERATING PLANT LONG-TERM STEAM DRYER INSPECTION PLAN 1.0 PURPOSE This document provides the long-term inspection plan for the Monticello Nuclear Generating Plant (MNGP) Replacement Steam Dryer (RSD) as required by the Renewed Facility Operating License No. DPR-22, License Condition 2.C.15(h). This license condition states:

At the end of the second refueling outage, following the implementation of the EPU [extended power uprate], the licensee shall submit a long-term steam dryer inspection plan based on industry operating experience along with the baseline inspection results for NRC review and approval.

A long-term inspection plan has been developed for the MNGP RSD as described below. This submittal of the plan satisfies License Condition 2.C.15(h) for the RSD.

2.0 LONG-TERM RSD INSPECTION PLAN INPUT A long-term steam dryer inspection plan has been developed for the MNGP following completion of the 2019 refueling outage. This outage was the second refueling outage following implementation of EPU. The inspection plan is based on:

Westinghouse letter, LTR-A&SA-12-8, Revision 1, Attachment A "Westinghouse Recommendations for Inspections of the Monticello Replacement Steam Dryer" This document was submitted to (attached to Reference 1) and reviewed by the NRC (as documented in Reference 2) during the EPU licensing process. LTR-A&SA-12-8, Revision 1, Attachment A, notes the steam dryer inspection plan will be based on, among other inputs, the general principles and conclusions from BWRVIP-139-A (Reference 3).

BWRVIP-139-A, Steam Dryer Inspection and Flaw Evaluation Guidelines BWRVIP-139-A is used for recommended inspection intervals, but not the recommended inspection locations due to the differences in geometry of the Nordic Design RSD.

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L-MT-19-047 NSPM Enclosure Inspection Results for the 2017 and 2019 Outages Nine weld locations were inaccessible for inspection or no weld was identified. No indications were found in 2017 (Reference 5). In 2019, one location was identified having two relevant indications. These were evaluated by the manufacturer to be acceptable for the next two refueling cycles prior to the next visual examination (Reference 6).

Recommendations from Westinghouse, the manufacturer of the Replacement Steam Dryer Westinghouse was contacted regarding any additional recommendations for inspection locations. No additional inspection locations recommended outside of the reexaminations after the next two refueling cycles of the two indications found in 2019 (Reference 4).

Recent industry operating experience Westinghouse was contacted regarding current operating experience of Westinghouse designed steam dryers. None of the industry operating experience resulted in a change to inspection recommendations for Monticello. No additional inspections are necessary due to recent operating experience (Reference 4).

3.0 PROPOSED LONG-TERM RSD INSPECTION PLAN The proposed inspection plan includes inspection of the various locations over ten-year periods. This frequency is consistent with the re-inspection frequency of BWRVIP-139 and Westinghouse recommendations.

Over the ten-year periods, the plan requires inspection of:

• All inspection locations in accordance with LTR-A&SA-12-8, Revision 1.

• All flaws found during inspections (re-inspections) in accordance with BWRVIP-139-1A re-inspection recommendations.

• The maximum stress location in accordance with Westinghouse recommendations (Reference 4).

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L-MT-19-04 7 NSPM Enclosure

4.0 REFERENCES

1. Letter L-MT-12-090, from NSPM to NRC, "Monticello Extended Power Uprate:

Replacement Steam Dryer- Inspection Criteria and Plan (TAC MD9990)", dated October 22, 2012 (ADAMS Accession Nos. ML12298A032 (non-proprietary NSPM letter) and ML12298A033 (non-proprietary version of Westinghouse letter, LTR-A&SA-12-8, Revision 1, Attachment A)

2. NRC letter to NSPM, "Monticello Nuclear Generating Plant - Issuance of Amendment No. 176 to Renewed Facility Operating License Regarding Extended Power Uprate (TAC No. MD9990)", dated December 9, 2013 (ADAMS Accession No. ML13316B298)

3. BWRVIP-139, Revision 1-A: "BWR Vessel and Internals Project: Steam Dryer Inspection and Flaw Evaluation Guidelines", EPRI, 2017

4. Letter LTR-PCBE-19-40-P, Revision 0, from Westinghouse to NSPM, "Long Term Inspection Recommendations for Monticello Replacement Steam Dryer", October 29, 2019

5. Letter L-MT-17-060 from NSPM to NRC, "Steam Dryer Visual Inspection Report", dated August 10, 2017 (ADAMS Accession No. ML17223A092)

6. Letter L-MT-19-028 from NSPM to NRC, "2019 Refueling Outage 90-Day lnservice Inspection (ISi) Summary Report; Second Steam Dryer Inspection Summary", dated August 9, 2019 (ADAMS Accession No. ML19221B714)

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