ML17292A142

Supplemental Information Needed for Acceptance of Relief Request No. 17-ON-001

ML17292A142
Person / Time
Site:	Oconee
Issue date:	10/26/2017
From:	Audrey Klett Plant Licensing Branch II
To:	Teresa Ray Duke Energy Carolinas
Klett A, NRR/DORL/LPLII-1
References
EPID L-2017-LLR-0099
Download: ML17292A142 (15)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 26, 2017 Mr. Thomas D. Ray Site Vice President Oconee Nuclear Station Duke Energy Carolinas, LLC 7800 Rochester Highway Seneca, SC 29672-0752

SUBJECT:

OCONEE NUCLEAR STATION, UNITS 1 AND 2 - SUPPLEMENTAL INFORMATION NEEDED FOR ACCEPTANCE OF RELIEF REQUEST NO. 17-0N-001 (EPID L-2017-LLR-0099)

Dear Mr. Ray:

By letter ONS-2017-072 dated October 3, 2017, Duke Energy Carolinas, LLC (the licensee) submitted Relief Request No. 17-0N-001 for the Oconee Nuclear Station, Units 1 and 2.

Pursuant to Title 1O of the Code of Federal Regulations (1 O CFR), Section 50.55a(z)(2), the licensee requested the U.S. Nuclear Regulatory Commission (NRC) to authorize a proposed alternative to the 7-year examination frequency requirement of the American Society of Mechanical Engineers Code Case N-770-2, Inspection Item B for the nozzle-to-safe end dissimilar metal butt welds associated with the Core Flood Nozzles. Section 50.55a(z)(2) states that an applicant must demonstrate that compliance with the specified requirements of Section 50.55a would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety.

This letter provides the results of the staff's (i.e., "the staff's") acceptance review of the licensee's application. The staff performs acceptance reviews to determine if an application contains sufficient technical information in scope and depth to allow the NRC staff to complete its detailed technical review and to render, in an appropriate time frame for the associated action, an independent assessment of the proposed action. The staff also performs acceptance reviews to identify whether an application has any readily apparent information insufficiencies in its characterization of the regulatory requirements or the licensing basis of the plant.

The staff reviewed the application concluded that it needs the information delineated in the enclosure to this letter to make an independent assessment regarding the acceptability of the application in terms of regulatory requirements and the protection of public health and safety and the environment. The staff requests the licensee to supplement its application to address the information requested in the enclosure within 13 business days from the date of this letter.

This will enable the staff to begin its detailed technical review. If the licensee does not submit the requested information within this time frame, the staff will not accept the application for review pursuant to 10 CFR 2.101 and will cease its review activities associated with the application. If the licensee submits the information within the requested time frame, the staff will notify the licensee if it subsequently accepts the application for review and, by separate correspondence, if it needs any further information to support its detailed technical review.

T. Ray The staff discussed the information requested and the associated time frame in this letter with Mr. David Haile of the licensee's staff on October 23, 2017.

Any inquiries regarding this matter can be directed to me at (301) 415-0489 or Audrey.Klett@nrc.gov.

Sincerely, Audrey Klett, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269 and 50-270

Enclosure:

Supplemental Information Needed cc: Listserv

SUPPLEMENTAL INFORMATION NEEDED RELIEF REQUEST NO. 17-0N-001 DUKE ENERGY CAROLINAS, LLC OCONEE NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-269 AND 50-270

Background

By letter dated October 3, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML17279A108), Duke Energy Carolinas, LLC (the licensee) submitted Relief Request No. 17-0N-001 for the Oconee Nuclear Station, Units 1 and 2. Pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a(z)(2), the licensee requested the U.S. Nuclear Regulatory Commission (NRG) to authorize a proposed alternative to the 7-year examination frequency requirement of the American Society of Mechanical Engineers Code Case N-770-2, Inspection Item B for the nozzle-to-safe end dissimilar metal butt welds associated with the Core Flood Nozzles. Section 50.55a(z)(2) states that an applicant must demonstrate that compliance with the specified requirements of Section 50.55a would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety.

During a public meeting held on May 25, 2017, the NRG staff (i.e., "the staff") provided a presentation about the information applicants would be expected to provide the staff in order for the staff to perform independent flaw evaluations during reviews of relief requests. The NRC's notice for the meeting is dated May 12, 2017, and is available at ADAMS Accession No. ML17132A164. The presentation slides are available in ADAMS at Accession No. ML17138A002 and are included in the attachment to this enclosure. Slide Nos. 6 through 9 describe the information that the staff needs to receive in applications for relief requests or proposed alternatives.

Insufficiencies The staff reviewed the application and concluded that it needs the following information to make an independent assessment regarding the acceptability of the application in terms of regulatory requirements and the protection of public health and safety and the environment.

1. The staff requests the licensee to provide detailed drawings of the welds in question.

The drawings, or additional supplemental data, should include the pipe outside diameter size, the weld thickness and the weld width as defined by slide 6 of the NRG presentation identified above. The drawings, or additional supplemental data, should also include details of any safe end weld, as well as the length from centerline of the dissimilar metal butt weld to the safe end weld. Further, any pipe bends or branch connections should be identified with distances from any and all such items to the centerline of the weld. The staff also requests the licensee to specify whether these components (i.e., pipe bends, branch connections, and safe end welds) have been evaluated as part of the licensee's weld residual stress profile for the dissimilar metal butt welds.

Enclosure

2. The staff requests the licensee to: (1) provide the weld residual stress inputs used for the licensee's flaw evaluation; (2) include a description of the methodology used to generate the weld residual stresses; (3) provide any references used to develop the through-weld thickness residual stresses, as well as all stress profiles used;, and (4) document for each profile if it included effects of pressure, temperature, shakedown and hydro pressure testing, and the value used for pressure, temperature and hydro, including the number of shakedown evolutions evaluated.

3. The staff requests the loadings used to perform the licensee's flaw analysis. In terms of forces, the staff requests the licensee to provide forces from deadweight, thermal, operational basis earthquake, safe shutdown earthquake, and loss of coolant accident.

If stresses are provided, the staff requests the licensee to document the axial membrane stress and global bending stress used for analysis ..

With the above information, it is expected that the staff can complete its independent assessment, including flaw calculations, of the licensee's proposed alternative to support the timeline requested by the licensee for review and approval.

ATTACHMENT NRC Independent Flaw Evaluations To Support Relief Requests For Dissimilar Metal Butt Welds Presentation dated May 25, 2017 ADAMS Accession No. ML17138A002 Attachment

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ML17292A142 *via email OFFICE N RR/DORL/LPL2-1 /PM NRR/DORL/LSPB/LAiT NRR/DMLR/MHPB/BC*

NAME A Klett IBetts DAiiey (JTsao for)

DATE 10/26/17 10/25/17 10/25/17 OFFICE NRR/DORL/LPL2-1 /BC NRR/DORL/LPL2-1/PM NAME MMarkley A Klett DATE 10/26/17 10/26/17