ML082610458

Upcoming Steam Generator Tube Inservice Inspection

ML082610458
Person / Time
Site:	San Onofre
Issue date:	09/24/2008
From:	Kalyanam N Plant Licensing Branch IV
To:	Ridenoure R Southern California Edison Co
Kalynanam N, NRR/DLPM,415-1480
References
TAC MD9640
Download: ML082610458 (6)

Text

September 24, 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 - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (TAC MD9460)

Dear Mr. Ridenoure:

Inservice inspections of steam generator (SG) tubes play a vital role in assuring SG tube integrity. The reporting requirements of plant Technical Specifications typically require submission of a report within 180 days following completion of the inspection. The content of the report includes:

1. The scope of inspections performed on each SG,

2. Active degradation mechanisms identified,

3. Nondestructive examination techniques utilized for each degradation mechanism,

4. Location, orientation (if linear), and measured sizes of service induced indications,

5. Number of tubes plugged during the inspection outage for each active degradation mechanism,

6. Total number and percentage of tubes plugged to date, and

7. The results of condition monitoring, including the results of tube pulls and insitu testing.

A telephone conference call has been arranged with members of your staff to discuss the results of the SG tube inspections to be conducted during the upcoming refueling outage for San Onofre Nuclear Generating Station, Unit 3. This conference call is tentatively scheduled to be held in the first week of November 2008, after the majority of the tubes have been inspected but before the SG inspection activities have been completed. The attached enclosure provides a list of discussion points for use by your staff in preparing for the proposed conference call.

R. T. Ridenoure The U.S. Nuclear Regulatory Commission (NRC) staff plans to document a summary of the phone conference, including any material that you provide to the NRC staff in support of the phone conference.

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:

SG Tube Inspection Discussion Points cc w/encl: See next page

ML082610458 OFFICE LPL4/PM LPL4/LA LPL4/BC LPL4/PM NAME NKalyanam GLappert MMarkley NKalyanam DATE 9/22/08 9/17/08 9/24/08 9/24/08 San Onofre Nuclear Generating Station (June 2008)

Units 2 and 3 cc:

Douglas K. Porter, Esquire Resident Inspector Southern California Edison Company San Onofre Nuclear Generating Station 2244 Walnut Grove Avenue c/o U.S. Nuclear Regulatory Commission Rosemead, CA 91770 Post Office Box 4329 San Clemente, CA 92674 Dr. David Spath, Chief Division of Drinking Water and Mayor Environmental Management City of San Clemente California Dept. of Health Services 100 Avenida Presidio 850 Marina Parkway, Bldg P, 2nd Floor San Clemente, CA 92672 Richmond, CA 94804 Mr. James T. Reilly Chairman, Board of Supervisors Southern California Edison Company County of San Diego San Onofre Nuclear Generating Station 1600 Pacific Highway, Room 335 P.O. Box 128 San Diego, CA 92101 San Clemente, CA 92674-0128 Mark L. Parsons Mr. James D. Boyd Deputy City Attorney California State Liaison Officer City of Riverside Vice Chair and Commissioner 3900 Main Street California Energy Commission Riverside, CA 92522 1516 Ninth Street, MS 31 Sacramento, CA 95814 Mr. Gary L. Nolff Assistant General Manager - Resources Mr. Gary Butner Riverside Public Utilities Acting Branch Chief City of Riverside, California Department of Public Health Services 3901 Orange Street Radiologic Health Branch Riverside, CA 92501 MS 7610, P.O. Box 997414 Sacramento, CA 95899-7414 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Vice President and Site Manager 612 E. Lamar Blvd., Suite 400 Southern California Edison Company Arlington, TX 76011-41254 San Onofre Nuclear Generating Station P.O. Box 128 Mr. Michael L. De Marco San Clemente, CA 92674-0128 San Diego Gas & Electric Company 8315 Century Park Ct. CP21G Mr. A. Edward Scherer San Diego, CA 92123-1548 Director, Nuclear Regulatory Affairs Southern California Edison Company San Onofre Nuclear Generating Station P.O. Box 128 San Clemente, CA 92674-0128

CONFERENCE CALL DISCUSSION POINTS REGARDING STEAM GENERATOR TUBE INSPECTION RESULTS SOUTHERN CALIFORNIA EDISON COMPANY SAN ONOFRE NUCLEAR GENERATING STATIO, UNIT 3 DOCKET NO. 50-362 The U.S. Nuclear Regulatory Commission (NRC) staff has prepared the following discussion points for consideration by Southern California Edison Company (SCE, the licensee) in preparing for a conference call arranged with the licensee to discuss the results of the steam generator (SG) tube inspections to be conducted during the upcoming fall 2008, Unit 3 refueling outage. This conference call is scheduled to be held towards the end of the planned SG tube inspections but before the unit completes the inspections and repairs. The NRC staff plans to document a summary of the conference call as well as any material that is provided in support of the call.

For the conference call, SCE should be prepared to:

1. Discuss any trends in the amount of primary-to-secondary leakage observed during the recently completed cycle.

2. Discuss whether any secondary side pressure tests were performed during the outage and the associated results.

3. Discuss any exceptions taken to the industry guidelines.

4. For each steam generator, provide a description of the inspections performed including the areas examined and the probes used (e.g., dents/dings, sleeves, expansion-transition, U-bends with a rotating probe), the scope of the inspection (e.g., 100% of dents/dings greater than 5 volts and a 20% sample between 2 and 5 volts), and the expansion criteria.

5. For each area examined (e.g., tube supports, dent/dings, sleeves, etc), provide a summary of the number of indications identified, todate, for each degradation mode (e.g., number of circumferential primary water stress corrosion cracking indications at the expansion transition). For the most significant indications in each area, provide an estimate of the severity of the indication (e.g., provide the voltage, depth, and length of the indication). In particular, address whether tube integrity (structural and accident induced leakage integrity) was maintained during the previous operating cycle. In addition, discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential primary water stress corrosion cracking at the expansion transition for the first time at this unit).

6. Describe repair/plugging plans.

7. Describe in situ pressure test and tube pull plans and results (as applicable and if available).

8. Discuss the following regarding loose parts:

$ inspections performed to detect loose parts,

$ a description of any loose parts detected and their location within the SG, including the source or nature of the loose part, if known,

$ loose parts removed from the SG, and

$ indications of tube damage associated with the loose parts.

9. Discuss the scope and results of any secondary side inspection and maintenance activities (e.g., in-bundle visual inspections, feed ring inspections, sludge lancing, assessing deposit loading, etc).

10. Discuss any unexpected or unusual results.

11. Provide the schedule for steam generator-related activities during the remainder of the outage.