ML090420064
| ML090420064 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/28/2009 |
| From: | Scherer A Southern California Edison Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| ISI-3-27 | |
| Download: ML090420064 (3) | |
Text
SOUTHERN CALIFORNIA A. Edward Scherer
___EDISON Director EDISON Nuclear Regulatory Affairs An EDISON INTERNATIONAL Company January 28, 2009 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
Subject:
Docket No. 50-361 Ultrasonic Test Results Related to Inservice Inspection (ISI)
Interval Relief Request ISI-3-27 for the Use of Structural Weld Overlay and Associated Alternative Repair Techniques San Onofre Nuclear Generating Station, Unit 2
References:
- 1. Letter from A. E. Scherer to the U. S. Nuclear Regulatory Commission dated November 12, 2008;
Subject:
Docket Nos. 50-361 and 50-362, Revision to Third Ten-Year Inservice Inspection (ISI) Interval Requests ISI-3-27 and ISI-3-28, Use of Structural Weld Overlay and Associated Alternative Repair Techniques, San Onofre Nuclear Generating Station, Units 2 and 3
- 2. Letter from T. G. Hiltz (NRC) to R. M. Rosenblum (NRC) dated December 13, 2007;
Subject:
San Onofre Nuclear Generating Station, Unit 2 and Unit 3 - Re: Request Approval to Use Alternatives to the Requirements of the American Society of Mechanical Engineers Code,Section XI, IWA-4000, for Repair/Replacement Activities Related to the Performance of Structural Weld Overlays (TAC Nos. MD4580 and MD4581)
- 3. Letter from A. E. Scherer (SCE) to the U. S. Nuclear Regulatory Commission dated November 24, 2008;
Subject:
Docket No. 50-362, Ultrasonic Test Results Related to Inservice Inspection (ISI) Interval Relief Request ISI-3-27 for the Use of Structural Weld Overlay and Associated Alternative Repair Techniques, San Onofre Nuclear Generating Station, Unit 3
Dear Sir or Madam:
The Reference 1 submittal proposed an alternative (ISI-3-27), 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 P.O. Box 128 San Clemente;,.CA 92672
Document Control Desk January 28, 2009 overlays on the San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 reactor coolant system hot leg nozzle-to-safe-end welds and the adjacent stainless steel welds.
Reference 1 was approved by the NRC as described in Reference 2.
Reference 1 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 overlays on the SONGS Units 2 and 3 reactor coolant system hot leg surge nozzle-to-safe-end weld, the reactor coolant system hot leg drain nozzle-to-safe-end weld, the shutdown cooling system hot leg nozzle to safe end weld, and the adjacent stainless steel welds to the NRC.
In accordance with the referenced 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 2 welds identified in ISI-3-27.
After completing the full structural weld overlay, SCE performed the required UT examination. The UT examination was completed on January 14, 2009, with the following results.
- 1. Reactor Coolant System Hot Leg surge nozzle to safe end HSS dissimilar metal weld (ISI Designation Number 02-006-010) with Alloy 82/182 weld material subject to PWSCC. No suspected flaw indications were observed during the examination.
- 2. Reactor Coolant System Hot Leg surge nozzle adjacent stainless steel weld (ISI Designation Number 02-016-016). No suspected flaw indications were observed during the examinations.
- 3. Reactor Coolant System Hot Leg drain nozzle to safe end HSS dissimilar metal weld (ISI Designation Number 02-006-011) with Alloy 82/182 weld material subject to PWSCC. No suspected flaw indications were observed within the required weld overlay examination volume (see below) during the examination.
- 4. Reactor Coolant System Hot Leg drain nozzle adjacent stainless steel weld (ISI Designation Number 02-030-001). No suspected flaw indications were observed within the required weld overlay examination volume (see below) during the examination.
- 5. Shutdown Cooling System Hot Leg nozzle to safe end HSS dissimilar metal weld (ISI Designation Number 02-007-009) with Alloy 82/182 weld material subject to PWSCC. No suspected flaw indications were observed during the examination.
Document Control Desk January 28, 2009
- 6. Shutdown Cooling System Hot Leg nozzle adjacent stainless steel weld (ISI Designation Number 02-021-001). No suspected flaw indications were observed during the examination.
During the examination of the weld overlay on the Reactor Coolant System Hot Leg drain line, one planar flaw was identified in the underlying nozzle base metal, outside the required weld overlay examination volume. This flaw was evaluated in accordance with the ASME Code, Section Xl, IWB-3500; the applicable acceptance standards were met and the flaw was found to be acceptable.
The structural weld overlays for the Unit 3 welds addressed in ISI-3-27 were completed during the Cycle 15 refueling outage. The results of the final ultrasonic test examinations on these welds were reported by letter dated November 24, 2008 (Reference 3).
Should you have any questions, please contact Ms. Linda T. Conklin at 949-368-9443.
Sincerely, cc:
E. E. Collins, Regional Administrator, NRC Region IV N. Kalyanam, NRC Project Manager, San Onofre Units 2 and 3 G. G. Warnick, NRC Senior Resident Inspector, San Onofre Units 2 and 3