ML032180634

8/6/03 - SONGS 2 - Evaluation of Steam Generator Tube Inspection Report from 2002 Outage (Tac. MB6564)

ML032180634
Person / Time
Site:	San Onofre
Issue date:	08/06/2003
From:	Bo Pham NRC/NRR/DLPM/LPD4
To:	Ray H Southern California Edison Co
Pham B
References
TAC MB6564
Download: ML032180634 (5)

Text

August 6, 2003 Mr. Harold Ray Executive Vice President 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 2 -

EVALUATION OF STEAM GENERATOR TUBE INSPECTION REPORT FROM 2002 OUTAGE (TAC NO. MB6564)

Dear Mr. Ray:

By letter dated June 14, 2002, as supplemented by letter dated June 19, 2002, Southern California Edison submitted to the Nuclear Regulatory Commission its special report summarizing the steam generator (SG) tube inspections for SONGS, Unit 2, completed in June 2002.

Enclosed is the NRC staffs evaluation of the SG tube inspection report. The staff did not identify any issues warranting additional plant-specific follow-up at this time.

Please contact me at (301) 415-8450 if you have any questions on this issue.

Sincerely,

/RA by B. Benney for/

Bo M. Pham, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-361

Enclosure:

Safety Evaluation cc: See next page

August 6, 2003 Mr. Harold Ray Executive Vice President 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 2 -

EVALUATION OF STEAM GENERATOR TUBE INSPECTION REPORT FROM 2002 OUTAGE (TAC NO. MB6564)

Dear Mr. Ray:

By letter dated June 14, 2002, as supplemented by letter dated June 19, 2002, Southern California Edison submitted to the Nuclear Regulatory Commission its special report summarizing the steam generator (SG) tube inspections for SONGS, Unit 2, completed in June 2002.

Enclosed is the NRC staffs evaluation of the SG tube inspection report. The staff did not identify any issues warranting additional plant-specific follow-up at this time.

Please contact me at (301) 415-8450 if you have any questions on this issue.

Sincerely,

/RA by B. Benney for/

Bo M. Pham, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-361

Enclosure:

Safety Evaluation cc: See next page DISTRIBUTION:

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San Onofre Nuclear Generating Station, Unit 2 cc:

Mr. Raymond Waldo, Plant Manager Mr. Ed Bailey, Radiation Program Director Nuclear Generation Radiologic Health Branch Southern California Edison Company State Department of Health Services San Onofre Nuclear Generating Station Post Office Box 942732 (MS 178)

P. O. Box 128 Sacramento, CA 94327-7320 San Clemente, CA 92674-0128 Resident Inspector/San Onofre NPS Mr. Douglas K. Porter 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 Mr. David Spath, Chief City of San Clemente Division of Drinking Water and 100 Avenida Presidio Environmental Management San Clemente, CA 92672 P. O. Box 942732 Sacramento, CA 94234-7320 Mr. Dwight E. Nunn, Vice President 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, Commissioner Eileen M. Teichert, Esq. California Energy Commission Supervising Deputy City Attorney 1516 Ninth Street (MS 31)

City of Riverside Sacramento, CA 95814 3900 Main Street Riverside, CA 92522 Mr. Joseph J. Wambold, Vice President Southern California Edison Company Mr. Gary L. Nolff San Onofre Nuclear Generating Station Power Projects/Contracts Manager P.O. Box 128 Riverside Public Utilities San Clemente, CA 92764-0128 2911 Adams Street Riverside, CA 92504 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Mr. Michael Olson San Diego Gas & Electric Company P.O. Box 1831 San Diego, CA 92112-4150 August 2002

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SPECIAL REPORT: IN SERVICE INSPECTION OF STEAM GENERATOR TUBES, CYCLE 12 SOUTHERN CALIFORNIA EDISON COMPANY SAN ONOFRE NUCLEAR GENERATING STATION (SONGS), UNIT 2 DOCKET NO. 50-361 By letters dated June 14 and 19, 2002, Southern California Edison (SCE) submitted its steam generator (SG) tube in service inspection report pursuant to Section 5.7.2.c of the technical specifications for SONGS, Unit 2. Subsequently, the NRC staff held a number of conference calls with the licensee, as summarized in NRC letter dated September 23, 2002, to discuss the results of SCEs findings.

SONGS, Unit 2 has two Combustion Engineering Model 3410 SGs, E-088 and E-089. Each SG has 9350 tubes (designed) which are fabricated with mill-annealed Alloy 600. The tubes in the tubesheet are installed with a full depth explosive expansion joint. The SONGS, Unit 2 SGs were inspected during Cycle 12 refueling outage in May and June 2002.

For SG E-088, SCE plugged 49 tubes and sleeved 75 tubes. The licensee detected inside and outside diameter axial indications at the eggcrate support intersections, inside and outside diameter circumferential indications at the top of tubesheet, inside diameter axial and circumferential indications below the top of tubesheet, and wear indications at the tube support intersections. The licensee also detected a limited number of outside diameter axial indications at the freespan region and outside diameter axial indications in the sludge pile at the top of the tubesheet.

For SG E-089, SCE plugged 52 tubes and sleeved 43 tubes. The licensee detected degradation in the same areas with the same mechanisms as in SG E-088. However, this SG has fewer number of indications in some degraded areas as compared to SG E-088, e.g., at the tubesheet and support intersections. The licensee also identified two volumetric indications at the top of tubesheet in E-089.

SCE performed in-situ pressure tests on a total of three indications. Two indications were outside diameter axial indications located at the eggcrate support intersections and one indication was tested for data quality issues in the U-bend region of a low row tube. All three indications satisfied the structural performance criteria without any leakage.

SCE has improved the secondary side chemistry to reduce the potential of SG tube degradation. The licensee has performed chemical cleaning of the tube bundle, added chemicals to inhibit stress corrosion cracking and to control the pH level of the coolant, added boric acid to reduce tube denting, and reduced the reactor coolant temperature at the SG inlet.

Based on our review of the licensees special report on the SG inspection at SONGS, Unit 2, the NRC staff concludes that the information required to be submitted per the technical specifications was adequately provided and that no additional follow-up is required at this time.

Principal Contributor: J. Tsao Date: August 6, 2003