ML073170693

Ultrasonic Test Results Related to Inspection (ISI) Interval Relief Request ISI-3-25 for the Use of Structural Weld Overlay and Associated Alternative Repair Techniques

ML073170693
Person / Time
Site:	San Onofre
Issue date:	11/09/2007
From:	Scherer A Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML073170693 (2)

Text

SOUTHERN CALIFORNIA A. Edward Scherer EDlISON Manager of Nuclear Regulatory Affairs An EDISON INTERNATIONAL Company November 9, 2007 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

Subject:

Docket No. 50-362 Ultrasonic Test Results Related to Inspection (ISI) Interval Relief Request ISI-3-25 for the Use of Structural Weld Overlay and Associated Alternative Repair Techniques San Onofre Nuclear Generating Station, Unit 3

References:

1) Letter from A. E. Scherer to the U. S. Nuclear Regulatory Commission dated July 14, 2006;

Subject:

Docket Nos. 50-361 and 50-362, Third Ten-Year Inservice Inspection (ISI) Interval Request ISI-3-25, Use of Structural Weld Overlay and Associated Alternative Repair Techniques, San Onofre Nuclear Generating Station, Units 2 and 3

2) Letter from A. E. Scherer to the U. S. Nuclear Regulatory Commission dated October 23, 2006;

Subject:

Docket Nos. 50-361 and 50-362, Additional Information Supporting the Third Ten-Year Inservice Inspection (ISI) Interval Relief Requests ISI-3-24 and ISI-3-25 for the Use of Structural Weld Overlay and Associated Alternative Repair Techniques, San Onofre Nuclear Generating Station, Units 2 and 3

Dear Sir or Madam:

The Reference 1 submittal proposed an alternative (ISI-3-25), in accordance with 10 CFR 50.55a(a)(3)(i), to the requirements of the American Society of Mechanical Engineers Code (ASME Code), Section Xl, 1995 Edition, through 1996 Addenda, IWA-4000, for repair/replacement activities related to the performance of structural weld overlays on the San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 pressurizer surge nozzle-to-safe-end welds and the adjacent stainless steel welds.

'The Reference 2 submittal provided additional information in support of the proposed alternative and included a commitment to provide a report that summarizes the results of the final ultrasonic (UT) examination within fourteen days of completion of the final UT examination of the structural weld o'erlays on the San Onofre Nuclear Generating Station Units 2 and 3 pressurizer surge nozzle-to-safe-end welds and the adjacent stainless steel welds to the NRC.

P.O. Box 128 San Clemente, CA 92672 949-368-7501 Fax 949-368-7575

Document Control Desk November 9, 2007 In accordance with the Reference 2 commitment, Southern California Edison (SCE) is providing the summary of UT results of the structural weld overlay on the San Onofre Nuclear Generating Station Unit 3 pressurizer surge nozzle-to-safe-end weld and the adjacent stainless steel weld.

After completing the full structural weld overlay on the Unit 3 pressurizer surge nozzle-to-safe-end weld and the adjacent stainless steel weld, SCE performed the required UT examination. The UT examination was completed on October 28, 2007, with the following results.

1. Pressurizer S31201 ME087 surge nozzle-to-safe-end HSS dissimilar metal weld (ISI Designation Number 03-005-031) - No suspected flaw indications, such as lack of bond, weld flaws, planar flaws, or laminar flaws, were observed during the examinations.

2. The adjacent Unit 3 Pressurizer S31201 ME087 stainless steel weld (ISI Designation Number 03-016-001) - No suspected flaw indications, such as lack of bond, weld flaws, planar flaws, or laminar flaws, were observed during the examinations.

A structural weld overlay is scheduled to be performed on the Unit 2 pressurizer surge nozzle-to-safe-end weld and the adjacent stainless steel weld during the upcoming Unit 2 Cycle 15 refueling outage. Consistent with SCE's commitment in Reference 2, SCE will submit a report to the NRC that summarizes the results of the final UT examination within fourteen days of completion of the final UT examination of the structural weld overlay on the SONGS Unit 2 pressurizer surge nozzle-to-safe-end weld and the adjacent stainless steel weld.

Should you have any questions, please contact Ms. Linda T. Conklin at 949-368-9443.

Sincerely, cc: E. E. Collins, Jr, Regional Administrator, NRC Region IV N. Kalyanam, NRC Project Manager, San Onofre Units 2 and 3 C. C. Osterholtz, NRC Senior Resident Inspector, San Onofre Units 2 and 3