NOC-AE-08002297, Unit 1 Weld Overlay Examination Results (RR-ENG-2-43) (TAC MD1414-1423)

Unit 1 Weld Overlay Examination Results (RR-ENG-2-43) (TAC MD1414-1423)

ML081270090
Person / Time
Site:	South Texas
Issue date:	04/29/2008
From:	Jenewein B South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-08002297, TAC MD1414, TAC MD1415, TAC MD1416, TAC MD1417, TAC MD1418, TAC MD1419, TAC MD1420, TAC MD1421, TAC MD1422, TAC MD1423
Download: ML081270090 (4)

Text

Nuclear Operating Company South Texas Pro/ectElectric Generation Stat/on P.O. ox 289 Wadsworth, Texas 77483 v April 29, 2008 NOC-AE-08002297 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 Unit 1 Docket Nos. STN 50-498 Unit 1 Weld Overlay Examination Results (RR-ENG-2-43) (TAC No. MD1414-1423)

Reference:

Letter from Brandon Jenewein, STPNOC, to NRC Document Control Desk, "Examination Results of a Pressurizer Nozzle Safe-End Weld Overlay (RR-ENG-2-43) (TAC Nos. MD1414-1423)," dated November 1,2006 Pursuant to 10 CFR 50.55a(a)(3)(i), 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. Ultrasonic examination of the weld overlays was to be performed to support NRC approval of the STPNOC request. STPNOC completed the ultrasonic examination for the South Texas Project Unit 1 pressurizer nozzle safe-end weld overlays on April 16, 2008, during the recent Unit 1 refueling outage (1RE14). A summary of the ultrasonic examination results for the Unit 1 pressurizer spray, relief, and safety nozzle safe ends is attached. The Unit 1 pressurizer surge nozzle was examined in October 2006 (1 RE1 3) and the results were reported as referenced above.

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) 972-7431.

Brandon Jenewein Manager, Testing/Programs PLW

Attachment:

Summary of Ultrasonic Examination Results for 1 RE1 4

/( 04-'

STI: 32305584

NOC-AE-08002297 Page 2 of 2 cc:

(paper copy) (electronic copy)

Regional Administrator, Region IV A. H. Gutterman, Esquire U. S. Nuclear Regulatory Commission Morgan, Lewis &.Bockius LLP 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064 Mohan C. Thadani U. S. Nuclear Regulatory Commission Mohan C. Thadani Thad Hill Senior Project Manager Steve Winn U.S. Nuclear Regulatory Commission Catherine Callaway One White Flint North (MS 7 D1) Brad Porlier 11555 Rockville Pike Eddy Daniels Rockville, MD 20852 Staney Rostad NRG South Texas LP Richard A. Ratliff J. J. Nesrsta Bureau of Radiation Control R. K. Temple Texas Department of State Health Services E. Alarcon 1100 West 49th Street Kevin Polio Austin, TX 78756-3189 City Public Service C. M. Canady C. Kirksey City of Austin City of Austin Electric Utility Department 721 Barton Springs Road Jon C. Wood Austin, TX 78704 Cox Smith Matthews Senior Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 289, Mail Code: MN116 Wadsworth, TX 77483

Attachment NOC-AE-08002297 Page 1 of 2 South Texas Project Unit 1 Summary of Ultrasonic Examination Results for 1 RE14 Ultrasonic Examination Procedure The weld overlay examinations were performed using Structural Integrity Associates procedure SI-UT-126, Revision 3, Procedure for the Phased Array Ultrasonic Examination of Weld Overlaid Similar and Dissimilar Metal Welds. The procedure and the examiners who applied the procedure are qualified through the Performance Demonstrative Initiative (PDI) Program at the Electric Power Research Institute Non-Destructive Examination Center.

Examination Regions: Weld Overlay Material, Outer 25% Dissimilar Metal Weld and Adjacent Base Material, and Outer 25% Safe End-to-Pipe Weld & Adjacent Base Material Axial Examination Angles: 00 through 840 Circumferential Examination Angles: 00 through 670 The examination gain was adjusted to maintain the procedure-specified baseline noise level from 5% to 20% of full screen height. The lower range of examination angles detected responses from the inside surface of the component which were useful for monitoring search unit contact / coupling effectiveness during the examination.

Spray Nozzle N2 Weld Overlay Examination Component Identification: PZR-1 -N2-SE-WOL Examination Summary: Examiridtion of the required volumes in the weld overlay and underlying upper 25% of the base material found no flaw indications. A small axial indication (length 0.7", through-wall dimension 0.16") in the underlying base metal was recorded at the inside diameter surface near the austenitic metal weld (Safe End-to-Pipe). The location is outside the scope of the weld overlay process. The indication is acceptable as evaluated to the criteria of ASME Section XI Code Case N-504-2, Appendix Q, and Table IWB-3514-2.

99.6% coverage of the Code-required volume was achieved for the weld overlay for the dissimilar metal weld (Safe End-to-Nozzle). 100% coverage of the Code-required volume was achieved for the weld overlay for the austenitic metal weld (Safe End-to-Pipe); the limitation is due to the nozzle configuration relative to the weld overlay.

Safety Nozzle N3 Weld Overlay Examination Component Identification: PZR-1 -N3-SE-WOL Examination Summary: Examination of the required volumes in the weld overlay identified two laminar indications in the weld overlay volume for the austenitic weld (Safe End-to-Elbow). The laminar indications were evaluated to the requirements of ASME Section XI Code Case N-504-2, Appendix Q, and Tables IWB-3514-3 and IWB-3514-2 and found to be acceptable. No flaw indications were found in the underlying upper 25% of the base material.

100% coverage of the Code-required volume was achieved.

Attachment NOC-AE-08002297 Page 2 of 2 Relief Nozzle N4A Weld Overlay Examination Component Identification: PZR-1-N4A-SE-WOL Examination Summary: Examination of the required volumes in the weld overlay and, underlying upper 25% of the base material found no flaw indications.

100% coverage of the Code-required volume was achieved.

Safety Nozzle N4B Weld Overlay Examination Component Identification: PZR-1-N4B-SE-WOL Examination Summary: Examination of the required volumes in the weld overlay and underlying upper 25% of the base material found no flaw indications.

100% coverage of the Code-required volume was achieved.

Safety Nozzle N4C Weld Overlay Examination Component Identification: PZR-1-N4C-SE-WOL Examination Summary: Examination of the required volumes in the weld overlay and underlying upper 25% of the base material found no flaw indications.

100% coverage of the Code-required volume was achieved.