ML081350232
| ML081350232 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 05/12/2008 |
| From: | Baxter D Duke Energy Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 07-ON-004 | |
| Download: ML081350232 (5) | |
Text
Duke DAVE BAXTER Vice President Energy, Oconee Nuclear Station Duke Energy Corporation ONO0 VP17800 Rochester Highway Seneca, SC 29672 864-885-4460
.864-885-4208 fax dabaxter@dukeenergy. com May 12, 2008 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555
Subject:
Duke Energy Carolinas, LLC Oconee Nuclear Station, Unit 1 Docket No. 50-269 Summary Ultrasonic Examination Results of Completed Alloy 82/182 Weld Overlays Relief Request 07-ON-004 By letter dated September 13, 2007, Duke submitted Relief Request (RR) 07-ON-004 (ADAMS Accession # ML072620149),
applicable to all three Oconee units, to seek relief related to full structural weld overlays on the Decay Heat Removal (DHR)
Drop line to Hot Leg Nozzle welds. The RR included a commitment to provide the results of the Ultrasonic Test (UT) examinations of the weld overlays within 14 days of completion of the UT examinations. The NRC staff provided verbal approval of RR 07-ON-004 on November 27, 2007 and written approval on January 17, 2008 (ADAMS Accession # ML073460027).
The Unit 1 UT examination of the DHR drop line weld overlays were completed April 29, 2008. No flaws outside the IWB-3514 criteria were identified, and no repairs were made to the weld overlays, the original base materials or original 82/182 weld materials. The attached Enclosure provides a report summarizing the results of these examinations, per the commitment contained in RR 07-ON-004.
If there are any questions, please contact Corey Gray at (864) 886-6325.
Very truly yours, Day Baxter, Vice President Oconee Nuclear Site 4L7 Enclosure A/OZ www. duke-energy,com
U3. S. Nuclear Regulatory Commission May 12, 2008 Page 2 cc: Mr. L. N. Qishan, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-14 H25 Washington, D.C. 20555' Mr. L. A. Reyes, Regional Administrator U.S. Nuclear Regulatory Commission -Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Mr. G. A. Hutto Senior Resident Inspector Oconee Nuclear Station S. E. Jenkins, Section Manager Bureau of Land and Waste Managemtent SC Dept. of Health & Environmental Control 2600 Bull St.
Columbia, SC 29201
U. S. Nuclear Regulatory Commission May 12, 2008 Page 3 bxc w/att:
R. L. Gill, Jr.
T. J. Coleman D. W. Peltola P. A. Wells D. H. Llewellyn C. R. Frye J. M. Shupping W. R. Cauthen A. D. Best B. W. Carney, Jr.
R. P. Todd C. A. Gray M. A. Pyne E. B. Miller, Jr.
L. C. Keith G. L. Brouette (ANII)
J. J. Mc Ardle III J. E. Smith ISI Relief Request File NRIA File/ELL EC050 Document Control
U. S. Nuclear Regulatory Commission May 12, 2008 Enclosure Weld Overlay Ultrasonic Examination lEOC24 Summary Report Decay Heat Removal Drop Line Weld Overlay Reference Relief Request 07-ON-004 Hot Leg Decay Heat Nozzle Welds:
I-LP-01-0140-25V Iof 2
U. S. Nuclear Regulatory Commission May 12, 2008 Ultrasonic Examination Procedure SI-UT-126, Revision 3, Procedurefor the PhasedArray UltrasonicExamination of Weld Overlaid Similar and DissimilarMetal Welds, was used for examinations of the Decay Heat Nozzle weld overlay (WOL). This procedure, and the examiner who applied the procedure, are qualified through the PDI Program at the EPRI NDE Center.
Decay Heat Nozzle Weld Overlay Examination Component Identification: DH Weld Overlay 1-LP-01-0140-25V Examination Date: 04/29/08 Examination Time: 11:45 - 13:00 Weld Overlay Regions Examined: Overlay, Weld and Base Material (Outer 25%)
Dissimilar Metal (DM) Weld Axial Examination Angles: 0' through 830 Circumferential Examination Angles: 00 through 70' Examination Summary: No suspected flaw indications were observed during the examinations. 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. During the course of the examinations, 100% coverage of the weld overlay material and 100% coverage of the Code-required volume for the DM welad was achieved.
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