ML063170071

Examination Results of a Pressurizer Nozzle Safe-End Weld Overlay (RR-ENG-2-43)

ML063170071
Person / Time
Site:	South Texas
Issue date:	11/01/2006
From:	Berg M South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-06002076, TAC MD1414, TAC MD1415, TAC MD1416, TAC MD1417, TAC MD1418, TAC MD1419, TAC MD1420, TAC MD1421, TAC MD1422, TAC MD1423
Download: ML063170071 (3)

Text

Nuclear Operating Company South Teas Pro/ect Electric Generastn$Statlon PO. Box289 Wadsworth, Texas 77483 v

November 1, 2006 NOC-AE-06002076 File No.: G25 10 CFR 50.55a U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Examination Results of a Pressurizer Nozzle Safe-End Weld Overlay (RR-ENG-2-43) (TAC Nos. MD1414-1423)

References:

(1) Letter dated May 1, 2006, from M. J. Berg, STPNOC, to NRC Document Control Desk, "Proposed Alternative to ASME Section XI Requirements for Application of a Weld Overlay (RR-ENG-2-43)," (NOC-AE-06002000)

(2) Letter dated August 22, 2006, from M. J. Berg, STPNOC, to NRC Document Control Desk, "Response to Request for Additional Information on Proposed Alternative to ASME Section XI Requirements for Application of a Weld Overlay (RR-ENG-2-43)," (NOC-AE-06002055)

(3) Letter dated September 28, 2006, from David W. Rencurrel, STPNOC, to NRC Document Control Desk, "Response to Request for Additional Information:

Proposed Alternative to ASME Section XI Requirements for Application of a Weld Overlay (RR-ENG-2-43)," (NOC-AE-06002068)

Pursuant to 10 CFR 50.55a(a)(3)(i), the STP Nuclear Operating Company (STPNOC) requested approval to use an alternative to the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code), Section Xl for the structural weld overlays on the South Texas Project Unit 1 and Unit 2 pressurizer spray, relief, safety and surge nozzle safe-ends. The request and supporting information were provided in references 1 and 2.

Verbal approval was given in subsequent discussions with the NRC.

As stated in the commitments documented in reference 3, STPNOC provides the results of weld overlay activities completed in the recent Unit 1 refueling outage (1 RE1 3).

The initial intent of the request for relief was for it to apply to six pressurizer nozzle safe ends in Unit 1 and in Unit 2. The Unit 1 task was subsequently reduced to three such safe ends for 1RE13. As the work progressed, two of the overlay welds were found to pose accessibility difficulties that could not be resolved consistent with the outage completion as scheduled and provide assurance that the weld would meet quality standards. Consequently, only the surge line nozzle safe-end weld overlay was completed during 1 RE1 3.

STPNOC completed the ultrasonic examination for the STP Unit 1 pressurizer surge nozzle weld overlay on October 24, 2006. Two indications were detected. The indications were found to be acceptable per the standards of ASME Section XI, IWB-3514-2 and/or IWB-3514-3 criteria for their respective size and position. The indications are laminar-type flaws located in the first STI: 32080823

NOC-AE-06002076 Page 2 of 3 weld layer at the base metal interface. No repairs to the overlay material and/or base metal were required or performed.

There are no commitments in this submittal.

If there are any questions, please contact either Mr. Philip Walker at (361) 972-8392 or me at (361) 972-7030.

M. J. Berg

Manager, Testing/Programs PLW

NOC-AE-06002076 Page 3 of 3 cc:

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Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Richard A. Ratliff Bureau of Radiation Control Texas Department of State Health Services 1100 West 49th Street Austin, TX 78756-3189 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 A. H. Gutterman, Esquire Morgan, Lewis & Bockius LLP Mohan C. Thadani U. S. Nuclear Regulatory Commission Steve Winn Christine Jacobs Eddy Daniels NRG South Texas LP C. Kirksey City of Austin J. J. Nesrsta R. K. Temple E. Alarcon City Public Service Jon C. Wood Cox Smith Matthews