ML092440189

Transmittal of Design Report for Structural Weld Overlays on Reactor Coolant System Hot Leg Dissimilar Metal Welds

ML092440189
Person / Time
Site:	San Onofre
Issue date:	08/27/2009
From:	Scherer A Southern California Edison Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML092440189 (3)

Text

~I SOUTHERN CALIFORNIA SOUTHERN CALIfORNIA A. Edward Scherer A. Edward Scherer s: EDISON Director Nuclear Nuclear Regulatory Regulatory Affairs An EDISON INTERNATIONAL Company August 27,27, 2009 U.

U. S. Nuclear Nuclear Regulatory ,Commission Regulatory.Commission Document ATTN: Document Control Desk Washington, D.C. 20555 Washington,

Subject:

50-361 and 50-362 Docket Nos. 50-361 50-362 Report for Structural Design Report Overlays on Structural Weld Overlays Reactor Coolant System Hot Leg Dissimilar Metal Welds Reactor Welds San Onofre Generating Station, Units 2 and 3 Nuclear Generating Onofre Nuclear

References:

1) Letter from A. E. Scherer

References:

Scherer (SCE) to the U. U. S. Nuclear Nuclear Regulatory Commission dated November November 12, 2008; 200B;

Subject:

Docket Docket Nos.

Revision to Third Ten-Year 50-361 and 50-362, Revision Inservice Ten-Year Inservice Inspection (ISI) Interval Inspection (lSI) ISI-3-28, Use of Interval Requests ISI-3-27 and ISI-3-2B, Overlay and Associated Structural Weld Overlay Repair Associated Alternative Repair Techniques, San Onofre Techniques, Onofre Nuclear Generating Station, Units 2 Nuclear Generating ML083220131) and 33 (ADAMS Accession No. MLOB3220131)

2) Letter Letter from M.M. T. Markley (NRC) to R. T. Ridenoure Markley (NRC) Ridenoure (SCE), dated January 23, 2009,

Subject:

January Nuclear Generating

Subject:

San Onofre Nuclear Generating Station, Units 2 and 3 - RE: Relief Requests ISI-3-27, Revision 1 ISI-3-28, Revision 1, and ISI-3-2B, 1, for the Application of Weld Overlay Overlay on Dissimilar and Similar Metal Welds (TAC Nos. ME010B Dissimilar ME0108 and ME0109)

ME0109)

Dear Sir or Madam:

The Design Report for the Structural Weld Overlays for the San Onofre Onofre Units 2 and 3 Reactor Coolant System System (RCS) Hot Leg Dissimilar Metal Welds is provided as an enclosure to this letter. Southern California enclosure committed to provide this California Edison (SCE) committed this report by letter letter dated November November 12, 200B 2008 (Reference (Reference 1).

Reference 1 requested Reference previously approved requested a Revision to previously Ten-Year Inservice approved Third Ten-Year Inservice (ISI) Interval Relief Requests Inspection (lSI)

Inspection ISI-3-27 Requests ISI-3-27 and ISI-3-28.

ISI-3-2B. These relief requests supported Structural Weld Overlays on the Dissimilar Metal Welds in implementation of Structural supported implementation in the San Onofre Onofre Units 2 and 3 RCS Hot Leg. During implementation implementation of these weld overlays overlays in the Unit 3 Cycle 15 Refueling discovered that the Unit 3 Hot Refueling outage, SCE discovered Hot Leg Surge Line includedincluded additional Code-allowed Weld buildup that had not been additional Code-allowed associated weld overlay identified. To resolve this, the design of the associated previously identified. overlay waswas including an additional weld. The length of the overlay, thereby including increase the length modified to increase The purpose of Revision 1 to ISI-3-27 and ISI-3-2B ISI-3-28 was to include additional weld in the include this additional the scope scope of the Relief Requests.

P.O. Box 128 C 2 .

Clemente, CA 92674 San Clemente, 92674

Document Control Desk Document August 27, 27, 2009 Due to the emergent emergent nature of the overlay design modification, a complete complete revision to the weld overlay design design analysis was not available at the time of submittal of Reference 1. In Reference In support Reference 1, the ASME support of Reference ASME Section Section III and Fatigue Crack Growth calculations were reviewed were reviewed and compared compared against the geometry geometry of the modified weld overlay. It It was conservatively conservatively concluded concluded that the previous analysis would remain valid for the modified modified geometry, and the modified weld overlay configuration configuration would be be acceptable acceptable for a minimum of one cycle.

The final analysis analysis has now been completed and the summary summary is included included in the the enclosed Design Report. Table 5-1 of this report shows the actual actual limiting crack growth results for each of the nozzles repaired.

Revision Revision 1 to ISI-3-27 ISI-3-27 and ISI-3-28 ISI-3-28 was approved approved by the U.

U. S. Nuclear Regulatory Commission Reference 2 (ADAMS Accession Commission by Reference Accession No. ML083640375)

ML083640375) for the duration of the third ten-year ten-year ISI lSI interval.

There are no new commitments commitments or required actions resulting from this letter.

If you have any questions If questions regarding this information, please feel free to contact Ms.

Linda T. Conklin at (949) 368-9443.

Sincerely, Enclosure Enclosure cc: E. E. Collins, Regional Administrator, NRC Region IV IV R. Hall, NRC NRC Project Manager, San OnofreOnofre Units 2 and 3 G. G. Warnick, NRC Senior ResidentResident Inspector, San Onofre Onofre Units 2 and 3

Enclosure Design Report for Structural Structural Weld Overlays Overlays San Onofre Nuclear Generating Generating Station Station Units 2 and 3 Reactor Reactor Coolant System System Hot Leg Dissimilar Metal Welds