ML082030720
| ML082030720 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/15/2008 |
| From: | Kalyanam N Plant Licensing Branch IV |
| To: | Ridenoure R Southern California Edison Co |
| Kalynanam N, NRR/DLPM,415-1480 | |
| Shared Package | |
| ML082030707 | List: |
| References | |
| TAC MD6835 | |
| Download: ML082030720 (14) | |
Text
August 15, 2008 Mr. Ross T. Ridenoure 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 - ISSUANCE OF AMENDMENTS RE: CONTAINMENT LEAKAGE RATE TESTING PROGRAM (TAC NO. MD6835)
Dear Mr. Ridenoure:
The Commission has issued the enclosed Amendment No. 210 to Facility Operating License No. NPF-15 for San Onofre Nuclear Generating Station, Unit 3 (SONGS 3). The amendments consist of changes to the Technical Specifications (TSs) in response to your application dated September 24, 2007, as supplemented by letters dated February 22 and March 27, 2008.
The amendment approves a TS change for SONGS 3, reflecting a one-time extension of the Section 50 of Title 10 of the Code of Federal Regulations (10 CFR 50) Appendix J, Type A, Integrated Leakage Rate Test interval from 15 years to 16 years. This is an additional 12 months beyond the 5-year extension already granted by the NRC staff to the nominal 10-year interval.
A copy of our related Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commission's next biweekly Federal Register notice.
Sincerely,
/RA by Jack Donohew for/
N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-362
Enclosures:
- 1. Amendment No. 210 to NPF-15
- 2. Safety Evaluation cc w/encls: See next page
Pkg ML082030707, Amendment ML082030720, License/TS Pgs ML082030733
- Only minor editorial changes made from Staff provided SEs OFFICE LPL4/PM LPL4/LA* DSS/SCVB* DRA/APLA&* DE/EMCB* OGC, NLO LPL4/BC (A) LPL4/PM RDennig MRubin NKalyanam, NAME NKalyanam GLappert KManoly EWilliamson JDonohew JND for DATE 8/4/08 8/4/08 7/9/08 7/9/08 7/15/08 8/14/08 8/15/08 8/15/08 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY THE CITY OF RIVERSIDE, CALIFORNIA DOCKET NO. 50-362 SAN ONOFRE NUCLEAR GENERATING STATION, UNIT 3 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 210 License No. NPF-15
- 1. The Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment by Southern California Edison Company, et al.
(SCE or the licensee), dated September 24, 2007, as supplemented by letters dated February 22 and March 27, 2008, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
- 2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and Paragraph 2.C(2) of Facility Operating License No. NPF-15 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No. 210, are hereby incorporated in the license. Southern California Edison Company shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3. This license amendment is effective as of the date of its issuance and shall be implemented within 60 days of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Jack N. Donohew, Acting Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to the Facility Operating License No. NPF-15 and Technical Specifications Date of Issuance: August 15, 2008
ATTACHMENT TO LICENSE AMENDMENT NO. 210 FACILITY OPERATING LICENSE NO. NPF-15 DOCKET NO. 50-362 Replace the following pages of the Facility Operating License No. NPF-15 and Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Facility Operating License REMOVE INSERT Page 3 Page 3 Technical Specifications REMOVE INSERT 5.0-20a 5.0-20a
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 210 TO FACILITY OPERATING LICENSE NO. NPF-15 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY THE CITY OF RIVERSIDE, CALIFORNIA SAN ONOFRE NUCLEAR GENERATING STATION, UNIT 3 DOCKET NO. 50-362
1.0 INTRODUCTION
By application dated September 24, 2007 (Reference 7.1), as supplemented by letters dated February 22 (Reference 7.2) and March 27 (Reference 7.3), 2008, Southern California Edison Company (the licensee) requested changes to the Technical Specifications (TSs) for San Onofre Nuclear Generating Station, Unit 3 (SONGS 3). The supplements dated February 22 and March 27, 2008, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the U.S.
Nuclear Regulatory Commission (NRC) staff original proposed no significant hazards consideration determination as published in the Federal Register on October 23, 2007 (72 FR 60036).
The amendment approves a TS change for SONGS 3, reflecting a one-time extension of the Section 50 of Title 10 of the Code of Federal Regulations (10 CFR 50) Appendix J, Type A, Integrated Leakage Rate Test interval from 15 years to 16 years. This is an additional 12 months beyond the 5-year extension already granted by the NRC staff to the nominal 10-year interval.
The amendment revises the SONGS 3 TS 5.5.2.15, "Containment Leakage Rate Testing Program." The request is for a one-time extension from the currently approved 15-year interval since the last Integrated Leak Rate Test (ILRT) to a 16 year interval. Thus, this change allows deferral of the next ILRT Type A Test from September 9, 2010 to prior to startup from the Unit 3 Cycle 16 refueling outage. This deferral will allow performance of the Type A ILRT during the planned steam generator replacement outage (Unit 3 Cycle 16 refueling outage) currently scheduled for the Fall of 2010.
2.0 REGULATORY EVALUATION
10 CFR Part 50, Appendix J, Option B (Reference 7.5) requires that a Type A test be conducted at a periodic interval based on historical performance of the overall containment system.
SONGS 3 TS 5.5.2.15, Containment Leakage Rate Testing Program requires that leakage rate testing be performed as required by 10 CFR 50.54(o) and 10 CFR 50, Appendix J, Option B, as modified by approved exemptions and in accordance with the guidelines contained in Regulatory Guide (RG) 1.163, Performance-Based Containment Leak-Test Program, (Reference 7.6) dated September 1995, with one exception (which is pertinent to the current request and is discussed in the next paragraph). This RG endorses, with certain exceptions, Nuclear Energy Institute (NEI) report NEI 94-01, Revision 0, Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J, dated July 26, 1995 (Reference. 7.7).
The Type A test measures an overall integrated leakage rate of the containment as a barrier against the release of fission products to the outside environment. NEI 94-01 specifies an initial test interval of 48 months, but allows an extended interval of 10 years, based upon two consecutive successful tests. There is also a provision for extending the test interval an additional 15 months in certain circumstances. The most recent two Type A tests at SONGS 3 (March 1992 and September 1995) have been successful, so the current interval requirement would normally be 10 years. However, by letter dated June 30, 2004, as supplemented by letters dated December 2, 2004, May 27, 2005, and July 18, 2005, the licensee requested a one-time extension of the test interval from 10 years to 15 years based on historical performance of its containment supported by a risk-informed analysis. On August 24, 2005, the NRC staff granted this request to SONGS 3 via License Amendment No. 189 which revised the TS to state that the specified Type A test shall be performed no later than September 2010 (Reference 7.4).
By Reference. 7.1, the licensee requested a proposed change to TS 5.5.2.15 which would alter their exception from the guidelines of RG 1.163 and NEI 94-01, by adding approximately 12 more months to the one-time, 15-year Type A test interval already in place, for a total interval of 16 years. Specifically, the change request states that the first Type A test performed after the September 1995 Type A test shall be performed prior to startup from the SONGS 3 Cycle 16 refueling outage which is currently scheduled to commence in the fall of 2010. During the Unit 3 Cycle 16 outage, the licensee plans to replace the steam generators.
The proposed TS change does not involve any other changes to licensing commitments or acceptance criteria. The test intervals for local leakage rate tests (Type B and Type C tests) are not affected by this license amendment request.
3.0 TECHNICAL EVALUATION
3.1 Containment Integrity This evaluation addresses the ability of the licensees In-service Inspection (ISI) program to detect and manage aging degradation/distress of the containment so that the leak-tight and
structural integrity of the containment will be maintained, if the ILRT test interval is extended as proposed by the licensee.
3.1.1 General The SONGS-3 containment pressure boundary consists of a prestressed, reinforced concrete cylindrical structure with a hemispherical dome and a conventionally reinforced concrete basemat, access penetrations (equipment hatch, air-locks), and other process piping and electrical penetrations. The leak tight integrity of the penetrations and isolation valves are verified through Type B and Type C local leak rate tests (LLRTs) and the overall leak-tight integrity of the primary containment is verified through a Type A ILRT as required by 10 CFR 50, Appendix J. These tests are performed at the design basis accident (DBA) pressure. The most recent Type A ILRT for SONGS-3 was performed in September 1995. By Reference 7.7, the NRC staff granted the licensee a one-time extension of the Type A test interval from 10 years (per guidelines of RG 1.163 and NEI 94-01) to 15 years based on historical performance of the containment supported by a risk-informed analysis. This amendment changed the TS to state that the specified Type A test shall be performed no later than September 9, 2010.
In Reference 7.1, the licensee has stated that compliance with the current TS would require performing the Type A test approximately two months prior to the Unit 3 Cycle 16 refueling outage (scheduled for fall 2010). This refueling outage will already require post-repair containment pressure testing due to the breach in containment for the planned steam generator (SG) replacement project. The planned SG replacement will require creating a large opening in the containment. Following the planned SG replacement during the Unit 3 Cycle 16 outage, the licensee will have to perform a pressure test as required by Subsections IWL 5000 and IWE 5000 to verify leak-tightness of the restored metal liner. Subsection IWL 5000 further requires a containment pressure test at the DBA pressure to verify the structural integrity of the restored containment. The licensee has stated that performing the Type A ILRT concurrent with the post repair containment pressure test prior to startup following SG replacement would avoid hardship from duplication and additional resources necessary to perform two containment pressure tests within 12 months at a small change in risk to the public.
The licensee justifies the proposed change to further extend the current ILRT interval based on historical plant specific ILRT test results and containment in-service inspection program (ISI) results, supported by a risk-informed analysis. The NRC staff evaluation is based on the understanding that the planned SG replacement outage (Unit 3 Cycle 16), during which the next ILRT is proposed to be conducted, will begin in the fall of 2010 as indicated by the licensee. As stated in the licensees submittal, the beginning of the SONGS-3 SG replacement outage only lags the currently approved September 9, 2010, date by approximately two months.
3.1.2 Containment ISI Program and Structural Integrity Considerations The leakage rate testing requirements of Reference 7.5 and the ISI requirements mandated by 10 CFR 50.55a complement each other in ensuring the leak-tight and structural integrity of the containment during its service life. The SONGS-3 containment is examined in accordance with the requirements of ASME Section XI, Subsections IWE and IWL, the Containment Leakage Testing program.
The licensee has stated that results from previous Type A ILRT testing demonstrate the containment structure remains essentially a leak-tight barrier and represents minimal risk.
These results were used to approve the original Type A ILRT extension from 10 to 15 years (Reference 7.4).
Furthermore, the licensee has emphasized that the ISI program based on 10 CFR 50.55a is implemented in accordance with the 1992 Edition with the 1992 Addenda of the ASME Boiler and Pressure Vessel Code,Section XI, Subsections IWE and IWL (Reference 7.8). Pursuant to 10 CFR 50.55a(b)(2)(ix)(E), a General Visual Examination of the containment liner as required by ASME Code Section XI, Subsection IWE must be performed during each Section XI ISI period of the ten-year interval. The initial ten-year inspection interval began September 9, 1998, and will end on September 8, 2008.
The licensee has stated in Reference 7.1 that SONGS-3 will perform the following actions during the upcoming Cycle 15 refueling outage (October 2008) prior to the end of the current 15-year ILRT time frame: (i) General visual examination of the containment surfaces required by 10 CFR 50.55a(b)(2)(ix)(E); (ii) Visual VT-3 examination of containment surfaces; (iii) Visual VT-3 examination of the containment surface vent system; (iv) Ultrasonic examination to verify minimum wall thickness of containment surfaces requiring augmented examination; (v) Visual VT-3 examination on Moisture Barriers; and (vi) Visual VT-1 examination on bolted connections.
SONGS-3 proposes to perform its next periodic Type A ILRT (to verify leak-tightness) in combination with the post-repair containment pressure test required per ASME Code Section XI IWL-5000 (to verify structural integrity of the restored containment following the major repair/replacement activity) during the Cycle 16 outage. To enable the NRC staff to gain an understanding of how the two tests would be performed in combination, the NRC staff requested the licensee to outline the main characteristics of the pressurization process and the extended surface examinations, additional examinations during pressurization, other examinations, and measurements of structural response to pressure of the affected areas/components of the post-repair containment structure, required by IWL-5250, that the licensee plans to conduct during the combined test. The NRC staff also requested the licensee to provide information on how these examinations and the ILRT would be relatively scheduled/sequenced during the combined test. By Reference. 7.3, the licensee stated that two tests will be performed concurrently, at a pressure of approximately 58 psig, following the completion of containment restoration work at the end of the steam generator replacement outage. The licensee also summarized the bases, pressurization sequence and planned activities associated with both tests. The NRC staff found the approach and procedure indicated by the licensee for performing the two tests and associated examinations rational, systematic and consistent with industry standards and regulatory guidance. For these reasons, the RAI response is acceptable to staff.
The NRC staff noted that a significant number of the tendons will be de-tensioned and removed in order to create an opening in the containment to facilitate SG replacement. The restoration of the containment will consist of the installation of some new tendons and other affected existing ones being re-tensioned after completion of the SG replacement. To ensure continued leak-tight integrity and structural integrity of the containment during its service life following the post-tensioning system repair/replacement activity, the NRC staff requested that the licensee identify the governing code and/or criteria for the inspection program of SONGS 3 which would
be affected by the repair and replacement activity. In its response, the licensee stated that the inspection activities associated with Section XI, Subsection IWE and IWL, of the ASME Code would be performed according to the 2001 Edition through the 2003 Addenda of the ASME Code (Reference 7.8). The use of the requirements in Subsection IWL of the 2001 Edition with the 2003 Addenda of Section XI of the ASME Code has been incorporated by reference in 10 CFR 50.55a with certain limitations and modifications.
In summary, to demonstrate acceptable performance of the containment, the licensee has cited successful previous Type A tests and Section XI of the ASME Code, Subsections IWE and IWL, in-service inspection findings and actions taken. The licensee reports that visual examinations and augmented examinations were conducted in accordance with Section XI of the ASME Code, and are to be conducted in the upcoming Cycle 15 outage (October 2008). Furthermore, as stated in References 7.4, the licensee has an adequate ISI program and procedures in place to periodically examine, monitor and manage age-related and environmental degradations of the pressure-retaining components of the primary containment, which the licensee has effectively implemented thus far. Since the primary containment aging degradations are effectively monitored and managed, there is reasonable assurance that the containment integrity will continue to be maintained without undue risk to safety during the requested 12-month extension period. Therefore, the NRC staff finds it acceptable to grant the requested 12-month extension to the current ILRT interval of 15 years.
3.1.3 Summary Based on the NRC staffs review of References 7.1, 7.2, and 7.4, the NRC staff concurs with the licensee determination that the SONGS 3 containment structure is in a sound condition and that the licensee has an adequate ISI program and procedures in place to examine, monitor and correct potential age-related and environmental degradations of the pressure retaining components of the primary containment. Therefore, the NRC staff concludes that granting a one-time approximately 12-month extension to the current 15-year interval for performing the ILRT as proposed by the licensee in Section 5.5.2.15 of the proposed TS revision request is acceptable.
3.2 Risk-informed Analysis 3.2.1 Technical Evaluation In Reference 7.4, the NRC approved a one-time extension of the containment ILRT interval from 10 to 15 years for SONGS 3. This test interval extension was supported by a licensee risk assessment. The NRCs review of the licensees risk assessment was documented in the SER for the license amendment, and concluded that the combined risk impact of the test interval extensions, in terms of total integrated plant risk, large early release frequency, and conditional containment failure probability, is small and supportive of the change.
By Reference 1, the licensee requested that TS 5.5.2.15 regarding the Containment Leakage Rate Testing Program be amended to effectively allow a one-time extension of the ILRT interval from 15 years to approximately 16 years for SONGS 3. The licensee performed a risk assessment of the impact of extending the ILRT test frequency from the original 3 tests in 10 years to one test in 16 years, and reported the risk results in the September 24, 2007,
application for license amendment. Additional information was provided by the licensee in its letter dated February 22, 2008. The risk assessment is based on the same methodology, input, and assumptions used to support License Amendment 189, with the exception of the revised test interval, the use of updated population dose estimates, and the use of an updated version of the PRA.
Based on the analyses provided by the licensee, the risk impacts and risk comparisons for the proposed change are not substantially changed from those reported in the previous SER, and the NRC staff conclusions remain valid. Specifically, the increase in the total integrated plant risk is small and supportive of the proposed change, the increase in the test interval results in only a small change in LERF consistent with the acceptance guidelines of RG 1.174, and the defense-in-depth philosophy is maintained based on the small magnitude of the change in the conditional containment failure probability.
3.2.2 Summary Based on these conclusions, the NRC staff finds that the increase in predicted risk due to the proposed change is within the acceptance guidelines while maintaining the defense-in-depth philosophy of RG 1.174 and, therefore, is acceptable. Therefore, the NRC staff finds that the interval until the next containment ILRT at SONGS 3 may be extended to 16 years, and that the proposed change to Technical Specification 5.5.2.15 is acceptable.
3.3 Conclusion Based on its conclusions in Sections 3.1.3 and 3.2.2 of this Safety Evaluation (SE), the NRC staff further concludes that the proposed amendment meets the regulatory requirements in Section 2.0 of this SE. Based on this, the NRC staff also concludes that the proposed amendment is acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the California State official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding published October 23, 2007 (72 FR 60036). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
7.0 REFERENCES
7.1 Letter from Brian Katz (Southern California Edison) to USNRC with regard to SONGS 3, Amendment Application No. 236, Proposed Change Number 582: Technical Specification 5.5.2.15 - Containment Leakage Rate Testing Program, San Onofre Nuclear Generating Station, Unit 3, dated September 24, 2007 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072681094).
7.2 Letter from A. Edward Scherer (Southern California Edison) to USNRC with regard to SONGS-3, Response to NRC Request for Additional Information in support of Amendment Application No. 236, Proposed Change Number (PCN) 582 Technical Specification (TS) 5.5.2.15 Containment Leakage Rate Testing Program, San Onofre Nuclear Generating Station, Unit 3, dates February 22, 2008 (ADAMS Accession No. ML080580474).
7.3 Letter from A. Edward Scherer (Southern California Edison) to USNRC with regard to SONGS-3, Response to NRC Request for Additional Information in support of Amendment Application No. 236, Proposed Change Number (PCN) 582 Technical Specification (TS) 5.5.2.15 Containment Leakage Rate Testing Program, San Onofre Nuclear Generating Station, Unit 3 dated March 27, 2008 (ADAMS Accession No. ML080940125).
7.4 Letter from Jack N. Donoshew (USNRC) to Southern California Edison with regard to San Onofre Nuclear Generation Station, Units 2 and 3 - Issuance of Amendments on Containment leakage Rate Testing Program (TAC Nos. MC3797 and MC3798), dated August 24, 2005, (ADAMS Accession No. ML052370051).
7.5 10 CFR, Part 50, Appendix J, Option B, Performance-Based Leakage-Test Requirements.
7.6 USNRC Regulatory Guide 1.163, Performance-Based Containment Leak-Test Program, September 1995.
7.7 Nuclear Energy Institute Document, NEI 94-01, Revision 0, Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J, July 1995.
7.8 ASME Boiler and Pressure Vessel Code,Section XI, Division 1, 1992 Edition including 1992 Addenda; and 2001 Edition including 2003 addenda.
Principal Contributors: H. Ashar, R. Palla, B. Lee, Date: August 15, 2008
San Onofre Nuclear Generating Station (June 2008)
Units 2 and 3 cc: Resident Inspector Douglas K. Porter, Esquire San Onofre Nuclear Generating Station Southern California Edison Company c/o U.S. Nuclear Regulatory Commission 2244 Walnut Grove Avenue Post Office Box 4329 Rosemead, CA 91770 San Clemente, CA 92674 Dr. David Spath, Chief Mayor Division of Drinking Water and City of San Clemente Environmental Management 100 Avenida Presidio California Dept. of Health Services San Clemente, CA 92672 850 Marina Parkway, Bldg P, 2nd Floor Richmond, CA 94804 Mr. James T. Reilly Southern California Edison Company Chairman, Board of Supervisors San Onofre Nuclear Generating Station County of San Diego P.O. Box 128 1600 Pacific Highway, Room 335 San Clemente, CA 92674-0128 San Diego, CA 92101 Mr. James D. Boyd Mark L. Parsons California State Liaison Officer Deputy City Attorney Vice Chair and Commissioner City of Riverside California Energy Commission 3900 Main Street 1516 Ninth Street, MS 31 Riverside, CA 92522 Sacramento, CA 95814 Mr. Gary L. Nolff Mr. Gary Butner Assistant General Manager - Resources Acting Branch Chief Riverside Public Utilities Department of Public Health Services City of Riverside, California Radiologic Health Branch 3901 Orange Street MS 7610, P.O. Box 997414 Riverside, CA 92501 Sacramento, CA 95899-7414 Regional Administrator, Region IV Vice President and Site Manager U.S. Nuclear Regulatory Commission Southern California Edison Company 612 E. Lamar Blvd., Suite 400 San Onofre Nuclear Generating Station Arlington, TX 76011-41254 P.O. Box 128 San Clemente, CA 92674-0128 Mr. Michael L. De Marco San Diego Gas & Electric Company Mr. A. Edward Scherer 8315 Century Park Ct. CP21G Director, Nuclear Regulatory Affairs San Diego, CA 92123-1548 Southern California Edison Company San Onofre Nuclear Generating Station P.O. Box 128 San Clemente, CA 92674-0128