ML060260498

(Songs), Unit 3 - Evaluation of the Response to Generic Letter 2004-01, Requirements for Steam Generator Tube Inspections

ML060260498
Person / Time
Site:	San Onofre
Issue date:	01/18/2006
From:	Terao D Plant Licensing Branch III-2
To:	Rosenblum R Southern California Edison Co
Kalyanam N,NRR/DLPM,415-1480
References
GL-04-001, TAC MC4850
Download: ML060260498 (5)

Text

January 18, 2006Mr. Richard M. RosenblumChief 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 (SONGS), UNIT 3 -EVALUATION OF THE RESPONSE TO GENERIC LETTER 2004-01, "REQUIREMENTS FOR STEAM GENERATOR TUBE INSPECTIONS" (TAC NO. MC4850)

Dear Mr. Rosenblum:

On August 30, 2004, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter(GL) 2004-01, "Requirements for Steam Generator Tube Inspections." The purpose of GL 2004-01 was to obtain information that would enable the NRC staff to determine whetherlicensees' steam generator tube inspection programs comply with the existing tube inspection requirements (the plant technical specifications in conjunction with Appendix B to Part 50 of Title 10 of the Code of Federal Regulations

).By letter dated October 26, 2004 (Agencywide Documents Access and Management System(ADAMS) Accession No. ML043020250), as supplemented by letter dated November 23, 2005 (ADAMS Accession No. ML053320210), Southern California Edison (SCE), the licensee for SONGS, submitted the response to GL 2004-01. The NRC Staff has reviewed the SCE response to GL 2004-01 for SONGS, Unit 3. Asdiscussed in the enclosed evaluation, the NRC staff concluded that the licensee's overallresponse to the GL is acceptable.If you have any questions, please call the Project Manager, N. Kalyanam, at (301) 415-1480.Sincerely,/RA/David Terao, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No. 50-362

Enclosure:

Staff Evaluation cc w/encl: See next page

ML053320210), Southern California Edison (SCE), the licensee for SONGS, submitted the response to GL 2004-01. The NRC Staff has reviewed the SCE response to GL 2004-01 for SONGS, Unit 3. Asdiscussed in the enclosed evaluation, the NRC staff concluded that the licensee's overallresponse to the GL is acceptable.If you have any questions, please call the Project Manager, N. Kalyanam, at (301) 415-1480.Sincerely,/RA/David Terao, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No. 50-362

Enclosure:

Staff Evaluation cc w/encl: See next pageDISTRIBUTIONPUBLICLPLIV r/fRidsNrrDorl (CHaney/CHolden)RidsNrrDorlLplg (DTerao)RidsNrrPMNKalyanamRidsNrrLALFeizollahiAHiserRidsAcrsAcnwMailCenterRidsOgcRpRidsRgn4MailCenter (TPruett)RidsNrrDorlDpr PKlein MYoder ACCESSION NO: ML060260498OFFICENRR/LPL4/PMNRR/LPL4/LANRR/LPL4/BCNAMENKalyanamLFeizollahiDTeraoDATE1/12/061/12/061/18/06 ENCLOSUREEVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIONRESPONSE TO NRC GENERIC LETTER 2004-01SOUTHERN CALIFORNIA EDISONSAN ONOFRE NUCLEAR GENERATING STATION, UNIT NO. 3DOCKET NO. 50-362On August 30, 2004, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2004-01, "Requirements for Steam Generator Tube Inspections." The purpose of GL 2004-01 was to obtain information that would enable the NRC staff to determine whetherlicensees' steam generator (SG) tube inspection programs comply with the existing tube inspection requirements the plant Technical Specifications (TSs) in conjunction with Appendix B of Title 10 of the Code of Federal Regulations (10 CFR) Part 50. Licensees who concluded that their SG tube inspections have not been or are not beingperformed consistent with the NRC's position on the requirements in the TSs, in conjunctionwith Appendix B of 10 CFR Part 50, were requested to submit a safety assessment. As part of the safety assessment, licensees were to address whether their safety bases for limiting inspections within the tubesheet constitutes a change to the "method of evaluation" for establishing the structural and leakage integrity of the tube-to-tubesheet joint. The NRC staffrequested this information since it was expected that licensees' safety bases relied on a mechanical expansion joint rather than the tube-to-tubesheet weld. Since the original tube-to-tubesheet joint was most likely designed by demonstrating that the stresses in the tube,weld, and tubesheet satisfy the allowable stress values in Section III of the American Society ofMechanical Engineers Boiler and Pressure Vessel Code (ASME Code), or other similar standard, the NRC staff questioned whether the safety basis for limiting inspections relied ondemonstrating that the expansion joint satisfied some criteria (e.g., minimum tube pullout load criteria, allowable leakage) beyond those specified in Section III of the ASME C ode.By letter dated October 26, 2004 (Agencywide Documents Access and Management System(ADAMS) Accession No. ML043020250), as supplemented by letter dated November 23, 2005 (ADAMS Accession No. ML053320210), Southern California Edison, the licensee for San Onofre Nuclear Generating Station (SONGS), Unit 3, submitted a response toGL 2004-01. In the response, you concluded that the safety basis used to support the tubeinspection practices does not constitute a change to the method of evaluation. This conclusion appears to be based, in part, on an assumption that the GL was implying that the selection ofnon-destructive evaluation techniques define the limits of the reactor coolant pressure boundary. The GL's discussion of the original design basis, however, was related to the "safety analysis" performed by certain licensees to support a conclusion that flaws located a certain distance below the top of the tubesheet do not have any safety implications. This safety basisrelies on a mechanical interference fit between the tube and the tubesheet for establishing the tube-to-tubesheet joint (i.e., forming the reactor coolant pressure boundary). However, formany plants (if not all), the original design of the steam generator gave no credit for this interference fit since the weld between the tube and the tubesheet ensured the integrity of thetube-to-tubesheet joint. In fact, the design rules (ASME Code,Section III) do not address theuse of an interference fit for maintaining pressure boundary integrity. As a result, the NRC staffquestioned whether licensees were using a different method of evaluation for assessing the adequacy of the tube-to-tubesheet joint.Although your response to the "method of evaluation" item did not focus on the NRC staff'sarea of concern, we conclude that your overall response to the GL is acceptable. You indicated that your tube inspection practices at SONGS, Unit 3, are not consistent with the NRC staffposition, and that this has been entered into your corrective action program. You further indicated that you plan on submitting a license amendment to clarify your steam generator tubeinspection practices in the tubesheet region. This license amendment request was submitted on November 3, 2005, and is currently being reviewed by the NRC staff. In the event that adifferent method of evaluation for the tube-to-tubesheet joint is in use at SONGS, Unit 3, it willbe reviewed as part of the license amendment process.Principal Reviewers:P. KleinM. YoderDate: January 18, 2006 November 2005San Onofre Nuclear Generating Station Units 2 and 3 cc:Mr. Daniel P. Breig Southern California Edison Company San Onofre Nuclear Generating Station

P. O. Box 128 San Clemente, CA 92674-0128Mr. Douglas K. Porter, EsquireSouthern California Edison Company 2244 Walnut Grove Avenue Rosemead, CA 91770Mr. David Spath, ChiefDivision of Drinking Water and Environmental Management P. O. Box 942732 Sacramento, CA 94234-7320Chairman, Board of SupervisorsCounty of San Diego 1600 Pacific Highway, Room 335 San Diego, CA 92101Eileen M. Teichert, Esq.Supervising Deputy City Attorney City of Riverside 3900 Main Street Riverside, CA 92522Mr. Gary L. Nolff Power Projects/Contracts Manager Riverside Public Utilities 2911 Adams Street Riverside, CA 92504Regional Administrator, Region IVU.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064Mr. Michael OlsonSan Diego Gas & Electric Company P.O. Box 1831 San Diego, CA 92112-4150Mr. Ed Bailey, ChiefRadiologic Health Branch State Department of Health Services Post Office Box 997414 (MS7610)

Sacramento, CA 95899-7414Resident Inspector/San Onofre NPS c/o U.S. Nuclear Regulatory Commission Post Office Box 4329 San Clemente, CA 92674Mayor City of San Clemente 100 Avenida Presidio San Clemente, CA 92672Mr. James T. Reilly Southern California Edison Company San Onofre Nuclear Generating Station

P.O. Box 128 San Clemente, CA 92674-0128Mr. James D. Boyd, CommissionerCalifornia Energy Commission 1516 Ninth Street (MS 31)

Sacramento, CA 95814Mr. Ray Waldo, Vice PresidentSouthern California Edison Company San Onofre Nuclear Generating Station

P.O. Box 128 San Clemente, CA 92764-0128Mr. Brian KatzSouthern California Edison Company San Onofre Nuclear Generating Station

P.O. Box 128 San Clemente, CA 92764-0128Mr. Steve HsuDepartment of Health Services Radiologic Health Branch MS 7610, P.O. Box 997414 Sacramento, CA 95899Mr. A. Edward SchererSouthern California Edison Company San Onofre Nuclear Generating Station

P.O. Box 128 San Clemente, CA 92674-0128