ML082470024

Correction 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

ML082470024
Person / Time
Site:	San Onofre
Issue date:	08/29/2008
From:	Scherer A Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML082470024 (3)

Text

SOUTHERN CALIFORNIA A. Edward Scherer Director V 1 u 2Nuclear Regulatory Affairs An EDISON INTERNATIONAL Company AUgust 29, 2008 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

Subject:

Docket Nos. 50-361 and 50-362 Correction to Third Ten-Year Inservice Inspection (ISI)

Interval Requests 181-3-27 and 11-3-28 Use of Structural Weld Overlay and Associated Alternative Repair Techniques San Onofre Nuclear Generating Station, Units 2 and 3

References:

See Attached

Dear Sir or Madam:

By letter dated February 21, 2007 (Reference 1), Southern California Edison (SCE) submitted ISI Relief Request ISI-3-27 in support of performing Structural Weld Overlays on Dissimilar Metal Welds (DMWs) on certain nozzles of the Hot Leg of the Reactor Coolant System (RCS) at San Onofre Units 2 and 3. This request was approved by letter from the NRC dated December 13, 2007 (Reference 2).

By letter dated August 1, 2007 (Reference 3), SCE submitted ISI Relief Request ISI-3-28. This submittal requested approval to begin the 48-hour hold period prior to post-weld Non-Destructive Examination (NDE) following application of the third temperbead layer. Relief Request ISI-3-28 applied to the weld overlays described in Reference 1 as well as additional weld overlays for the Pressurizer surge nozzles. This request was approved by letter from the NRC dated December 13, 2007 (Reference 4).

The weld overlays for the RCS Hot Leg nozzles are planned to be implemented in the upcoming Unit 3 Cycle 15 Refueling Outage (currently scheduled to begin on October 13, 2008) and the Unit 2 Cycle 15 Mid-cycle outage (currently scheduled to begin on December 30, 2008). In the detailed preparation for implementation of these weld overlays, SCE has discovered a need to correct References 1 and 3. In those letters, the base material specification for the Hot Leg Surge Line nozzle forging and the Shutdown Cooling Line nozzle forging was identified as SA-105 Grade IIfor both Units 2 and 3. SCE has determined P.O. Box 128 do 4 7 1/(

San Clemente, CA 92674

4, Document Control Desk August 29, 2008 that for Unit 2 that information is correct; however, for Unit 3, the base material specification for these two nozzles is SA-541 Class 1.

SCE has reviewed References 1 and 3 and the associated Safety Evaluation Reports (SERs) and has determined, based on the similar properties of the two materials, that the conclusions of our requests are not changed.

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

Sincerely,

Attachment:

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

I - - -

Attachment 1 References

1. Letter from A. E. Scherer (SCE) to Document Control Desk (NRC) dated February 21, 2007,

Subject:

Docket Nos. 50-361 and 50-362, Third Ten-Year Inservice Inspection (ISI) Interval Relief Request, ISI-3-27 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 (SCE) 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 Xl, 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 Document Control Desk (NRC) dated August 1, 2007,

Subject:

Docket Nos. 50-361 and 50-362, Third Ten-Year Inservice Inspection (ISI) Interval Request ISI-3-28, 48-hour Hold Period, San Onofre Nuclear Generating Station, Units 2 and 3

4. Letter from T. G. Hiltz (NRC) to R. M. Rosenblum (SCE) 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 for Mechanical Engineers Code, Section Xl, IWA-4000, for Repair/Replacement Activities Related to the Performance of Structural Weld Overlays (TAC Nos. MD6256 and MD6257)