1CAN110804, Summary of Weld Overlay Ultrasonic Examinations of Hot Leg Nozzle Dissimilar Metal Weld for Alloy 600 Mitigation at ANO-1

Summary of Weld Overlay Ultrasonic Examinations of Hot Leg Nozzle Dissimilar Metal Weld for Alloy 600 Mitigation at ANO-1

ML083240469
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/19/2008
From:	James D Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
1CAN110804
Download: ML083240469 (4)

Text

Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-4619 Dale E. James Manager, Licensing Arkansas Nuclear One 1CAN110804 November 19, 2008 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Summary of Weld Overlay Ultrasonic Examinations of Hot Leg Nozzle Dissimilar Metal Weld for Alloy 600 Mitigation at ANO-1 Arkansas Nuclear One, Unit 1 Docket No. 50-313 License No. DPR-51

REFERENCE:

NRC Letter to Entergy dated June 18, 2008 Approval of Relief Request ANO1-R&R-011 to Use a Proposed Alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Requirements for Weld Overlay Repairs (1CNA060801)

Dear Sir or Madam:

By the reference letter dated June 18, 2008, the NRC approved the request by Entergy Operations, Inc (Entergy) for relief from the requirements of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, Subsection IWA-4000 for mitigating primary water stress corrosion cracking (PWSCC) on a dissimilar metal weld (DMW) of the A hot leg nozzle to decay heat piping using the full structural weld overlay for Arkansas Nuclear One, Unit 1 (ANO-1).

As part of the request and repeated in the reference letter, Entergy committed to submit the following information to the NRC within 14 days following completion of final Ultrasonic (UT) examinations of the weld overlays:

(a) the weld overlay examination results including a listing of indications detected, (b) the disposition of all indications using the standards of ASME Code,Section XI, IWB-3514-2 and/or IWB-3514-3 criteria and, if possible, the type and nature of the indications, and (c) a discussion of any repairs to the weld overlay material and/or base metal and the reason for the repairs.

1CAN110804 Page 2 of 2 This information is provided in the attachment to this letter. The final UT examination of the weld overlay was completed on November 10, 2008.

This letter contains no new commitments.

If you have any questions or require additional information, please contact Dale James at 479-858-4619.

Sincerely, DEJ/dbb

Attachment:

Summary of Weld Overlay Ultrasonic Examination of Hot Leg Nozzle Dissimilar Metal Weld for Alloy 600 Mitigation at ANO-1 cc: Mr. Elmo E. Collins Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Arkansas Nuclear One P.O. Box 310 London, AR 72847 U.S. Nuclear Regulatory Commission Attn: Mr. Alan B. Wang MS O-7 D1 Washington, DC 20555-0001 Mr. Bernard R. Bevill Director Division of Radiation Control and Emergency Management Arkansas Department of Health & Human Services P.O. Box 1437 Slot H-30 Little Rock, AR 72203-1437

ATTACHMENT 1CAN110804

SUMMARY

OF WELD OVERLAY ULTRASONIC EXAMINATION OF HOT LEG NOZZLE DISSIMILAR METAL WELD FOR ALLOY 600 MITIGATION AT ANO-1

Attachment to 1CAN110804 Page 1 of 1 Summary of Weld Overlay Ultrasonic Examination of Hot Leg Nozzle Dissimilar Metal Weld for Alloy 600 Mitigation at ANO-1 Ultrasonic Examination Procedure SI-UT-126, Revision 3, Procedure for the Phased Array Ultrasonic Examination of Weld Overlaid Similar and Dissimilar Metal Welds, was used for examination of the Hot Leg Decay Heat Nozzle weld overlay (WOL). This procedure, and the examiners who applied the procedure, are qualified through the PDI Program at the EPRI NDE Center.

Hot Leg Decay Heat Nozzle Weld Overlay Examination Component Identification: Hot Leg Decay Heat Nozzle Weld Overlay (Weld: 17-017)

Examination Date: 11/10/08 Examination Time: 18:01 - 19:25 CST Weld Overlay Regions Examined: Overlay, Weld and Base Material (Outer 25%) Dissimilar Metal (DM) Weld Axial Examination Angles: 0° through 84° Circumferential Examination Angles: 0° through 62° (Minimum Range)

Examination Summary No suspected flaw indications were observed during the examination. 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 examination, 100% coverage of the weld overlay material was achieved and 100% coverage of the Code-required volume (CRV) for the DM weld was achieved.