ML073111398

Request for Additional Information 2006 Steam Generator Tube Inspections

ML073111398
Person / Time
Site:	San Onofre
Issue date:	11/15/2007
From:	Kalyanam N NRC/NRR/ADRO/DORL/LPLIV
To:	Rosenblum R Southern California Edison Co
Kalyanam N, NRR/DORL/LPL4, 415-1480
References
TAC MD5953
Download: ML073111398 (4)

Text

November 15, 2007 Mr. Richard M. Rosenblum Senior Vice President and Chief Nuclear Officer Southern California Edison Company San Onofre Nuclear Generating Station P.O. Box 128 San Clemente, CA 92674-0128

SUBJECT:

SAN ONOFRE NUCLEAR GENERATING STATION, UNIT 3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING THE 2006 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. MD5953)

Dear Mr. Rosenblum:

By letter dated May 25, 2007 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML071520093), Southern California Edison (the licensee) submitted information pertaining to their 2006 steam generator (SG) tube inspections at the San Onofre Nuclear Generating Station, Unit 3. In addition to the above report, the U.S. Nuclear Regulatory Commission (NRC) staff, in its letter dated December 18, 2006 (ADAMS Accession No. ML063450305), summarized conference call discussions concerning the 2006 SG tube inspections at San Onofre, Unit 3.

After reviewing the submitted information, the NRC staff has determined that additional information is needed to complete the review evaluation. Please provide a response to the enclosed request for additional information within 30 days of the receipt of this letter.

If you have any questions, please contact me at (301) 415-1480.

Sincerely,

/RA/

N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-362

Enclosure:

Request for Additional Information cc w/encl: See next page

ML063450305), summarized conference call discussions concerning the 2006 SG tube inspections at San Onofre, Unit 3.

After reviewing the submitted information, the NRC staff has determined that additional information is needed to complete the review evaluation. Please provide a response to the enclosed request for additional information within 30 days of the receipt of this letter.

If you have any questions, please contact me at (301) 415-1480.

Sincerely,

/RA/

N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-362

Enclosure:

Request for Additional Information cc w/encl: See next page DISTRIBUTION:

PUBLIC LPLIV r/f RidsAcrsAcnwMailCenter RidsNrrDciCsgb RidsNrrDorlDpr RidsNrrDorlLpl4 RidsNrrDorl RidsNrrLAJBurkhardt RidsNrrPMNKalyanam RidsOgcrp RidsRgn4MailCenter (JClark) AJohnson, DCI/CSGB ADAMS Accession No.: ML073111398 NRR-088 *No major change from Staff provided RAI OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/DCI/CSGB* NRR/LPL4/BC NAME NKalyanam:sp JBurkhardt AHiser THiltz DATE 11/15/07 11/9/07 11/15/07 San Onofre Nuclear Generating Station Units 2 and 3 cc:

Mr. Raymond W. Waldo, Vice President, Director, Radiologic Health Branch Nuclear Generation State Department of Health Services Southern California Edison Company P.O. Box 997414, MS 7610 San Onofre Nuclear Generating Station Sacramento, CA 95899-7414 P.O. Box 128 San Clemente, CA 92674-0128 Resident Inspector San Onofre Nuclear Generating Station Mr. Douglas K. Porter, Esquire c/o U.S. Nuclear Regulatory Commission Southern California Edison Company Post Office Box 4329 2244 Walnut Grove Avenue San Clemente, CA 92674 Rosemead, CA 91770 Mayor Dr. David Spath, Chief City of San Clemente Division of Drinking Water and 100 Avenida Presidio Environmental Management San Clemente, CA 92672 California Dept. of Health Services 850 Marina Parkway, Bldg P, 2nd Floor Mr. James T. Reilly Richmond, CA 94804 Southern California Edison Company San Onofre Nuclear Generating Station Chairman, Board of Supervisors P.O. Box 128 County of San Diego San Clemente, CA 92674-0128 1600 Pacific Highway, Room 335 San Diego, CA 92101 Mr. James D. Boyd, Commissioner California Energy Commission Mark L. Parsons 1516 Ninth Street (MS 31)

Deputy City Attorney Sacramento, CA 95814 City of Riverside 3900 Main Street Brian Katz Riverside, CA 92522 Southern California Edison Company San Onofre Nuclear Generating Station Mr. Gary L. Nolff P.O. Box 128 Assistant Director - Resources San Clemente, CA 92764-0128 City of Riverside 3900 Main Street, 4th Floor Mr. Steve Hsu Riverside, CA 92522 Department of Health Services Radiologic Health Branch Regional Administrator, Region IV MS 7610, P.O. Box 997414 U.S. Nuclear Regulatory Commission Sacramento, CA 95899-7414 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Mr. A. Edward Scherer Southern California Edison Company Mr. Michael L. DeMarco San Onofre Nuclear Generating Station San Diego Gas & Electric Company P.O. Box 128 8315 Century Park Ct. CP21G San Clemente, CA 92674-0128 San Diego, CA 92123-1548 October 2007

REQUEST FOR ADDITIONAL INFORMATION STEAM GENERATOR TUBE INSERVICE INSPECTION REPORTS FOR THE 2006 REFUELING OUTAGE SAN ONOFRE NUCLEAR GENERATING STATION - UNIT 3 DOCKET NUMBER 50-362

1. Please provide the scope and results of any secondary side inspections (including foreign object search and retrieval) performed during the 2006 outage. In addition, please discuss the scope and results of any inspections performed of the batwings in the stay cavity regions. Please confirm that all detected loose parts were removed from the steam generator (SG). If loose parts were left in the SG, please discuss whether analyses were performed to assess whether tube integrity would be maintained with the loose parts left in the SG.

2. Please discuss the data quality and as low as reasonably achievable (ALARA) issues that led to plugging two tubes. Please discuss how you confirmed that tube integrity was maintained for these two tubes.

3. Please discuss the basis for only performing rotating probe inspections of the U-bend region out through row 10 (given that a similarly designed unit has found axial cracking in the U-bend in row 14).

4. In evaluating the nondestructive examination techniques in Table 3 of Reference 1, it does not appear that you inspected for axial and circumferential primary water stress-corrosion cracks in dings or circumferentially oriented outside diameter stress-corrosion cracks in dings. Please confirm that the techniques used to inspect the dings were capable of finding these degradation mechanisms. In addition, please clarify what rows of tubes are considered low row U-bends, and please clarify what degradation mechanisms were inspected for in the U-bend region.

5. Please confirm that Table 4 in Reference 1 contains all crack-like (axial, circumferential, or mixed-mode) indications detected during the SG tube inspections. Please confirm that all crack-like indications were plugged.

6. Several wear indications appear to be outside the tube supports (e.g., row 49, column 129 in SG 89). Please discuss whether any wear indication was located outside the tube support. If so, discuss the extent to which the support may have moved due to degradation of the support.

Reference:

1. Letter from A. E. Scherer to USNRC dated May 5, 2007, Special Report: Inspection of Steam Generator Tubes, Cycle 14, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML071520093).