ML11180A011

Closure of 60-Day Interim Report Notification: Dubose National Energy Services, Inc

ML11180A011
Person / Time
Site:	Oconee
Issue date:	06/23/2011
From:	Gillespie T Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
O-10-08732
Download: ML11180A011 (3)

Text

Duke T.PRESTON GILLESPIE, JR.

Vice President Oconee Nuclear Station Duke Energy ON01 VP / 7800 Rochester Hwy.

Seneca, SC 29672 864-873-4478 864-873-4208 fax June 23, 2011 T.Gillespie@duke-energy.corn U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station Docket Nos. 50-269, -270, -287 Closure of 60-Day Interim Report Notification: DuBose National Energy Services, Inc.

Problem Investigation Program No.: 0-10-08732 Gentlemen:

Duke Energy Carolinas, LLC (Duke Energy) submitted an Interim Report of the Evaluation of a Deviation on February 17, 2011, as required by 10CFR21.21(a)(2). The deviation being evaluated was compliance with the American Welding Society (AWS) standard AWS D1.1 with respect to fabrication activities associated with the Natural Phenomenon Barrier System project. Fluor has procurement responsibility for this contract. DuBose National Energy Services, Inc. is contracted to supply the materials and fabrication services through its contract with Fluor for the project.

The attachment to this letter provides the information to close the Interim Report for this concern. Duke Energy has concluded that the identified deviation would not have resulted in a substantial safety hazard; therefore, no defect exists. This issue is not reportable per 1 OCFR21. There are no commitments contained in this letter or its attachment.

Should you have any questions or require additional information, please contact Sandra N. Severance, ONS Regulatory Compliance, at (864) 873-3466.

Sincerely, T. Preston Gillespie, Jr., Vice President Oconee Nuclear Station Attachment www. duke-energy. corn

U.S. Nuclear Regulatory Commission June 23, 2011 Page 2 cc: Mr. Victor McCree Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. John Stang Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Mail Stop 08-G9A Washington, D.C. 20555 Mr. Andrew Sabisch NRC Senior Resident Inspector Oconee Nuclear Station Mr. Doug Vickery, Director of Quality DuBose National Energy Services, Inc.

900 Industrial Drive PO Box 499 Clinton, NC 28329 Mr. Ram Prabhakar Fluor Quality Engineering Manager Oconee Project

Attachment Oconee Nuclear Station Closure of 60-Day Interim Report Notification

Subject:

Closure of the 60-Day Interim Report Notification regarding evaluation of a deviation pursuant to 10CFR21.21(a)(2)

Issue:

Compliance with the American Welding Society (AWS) standard AWS D1.1 with respect to fabrication activities associated with the Oconee Nuclear Station Natural Phenomenon Barrier System project Basic Component Supplied By:

Fabricated Structural Steel Components for the Natural Phenomenon Barrier System (NPBS), ONS Units 1, 2, and 3 supplied by DuBose National Energy Services, Inc. (DuBose)

Nature of Deviation:

When removing weld run-out tabs beyond the weld joint on fabricated assemblies, weld discontinuities suspected to be porosity were discovered in the trimmed areas. Evaluation by Fluor and Duke Energy personnel concluded that process shortcomings existed in the DuBose welding efforts since examples of lack of fusion with the weld metal and the weld metal backing bar and lack of penetration into the root of the weld were identified. DuBose was then required to remove all backing bars and weld tabs, inspect the weld for indications and document, and make repairs if required. Duke Energy and Fluor returned to DuBose the suspect fabricated steel that contained welding backing bars and run-out tabs. All backing bars and run-out tabs were removed, welds inspected, mapped and repaired.

Evaluation:

Duke Energy, through Fluor Engineering (Aliso Viejo, CA), initiated an engineering evaluation to determine the structural adequacy of the fabricated steel components for use in the NPBS for the Borated Water Storage Tanks as well as the West Penetration and Decontamination Tank rooms.

Based on the worst-case welded connection and using conservative assumptions, the weld's demand to capacity ratio is 0.5, so the design function of the NPBS would still be met.

Based on the above results, it has been determined that this issue does not represent a substantial safety hazard.