ML080840453
| ML080840453 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 03/25/2008 |
| From: | Markley M NRC/NRR/ADRO/DORL/LPLIV |
| To: | Edington R Arizona Public Service Co |
| Markley, M T, NRR/DORL/LP4, 301-415-5723 | |
| References | |
| TAC MD5981 | |
| Download: ML080840453 (5) | |
Text
March 25, 2008 Mr. Randall K. Edington Executive Vice President Nuclear/
Chief Nuclear Officer Mail Station 7602 Arizona Public Service Company P. O. Box 52034 Phoenix, AZ 85072-2034
SUBJECT:
PALO VERDE NUCLEAR GENERATING STATION, UNIT 3 - RESULTS OF 12TH STEAM GENERATOR TUBE INSPECTION (TAC NO. MD5981)
Dear Mr. Edington:
By letters dated May 4, 2006, and March 23, 2007, Arizona Public Service Company (APS, the licensee) submitted information pertaining to its 2006 steam generator (SG) tube inspections for the Palo Verde Nuclear Generating Station (Palo Verde), Unit 3, Facility Operating License No. NPF-74. These inspections were performed during the 12th refueling outage of Unit 3. The U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with APS concerning the 2006 SG tube inspection results at Palo Verde, Unit 3, and documented the discussions in a letter dated August 23, 2006.
Based on a review of the material provided by APS, the NRC staff concludes that the licensee provided the information required for SG tube inspections by the plant technical specifications.
In addition, the NRC staff did not identify any issues that warrant follow-up at this time. The NRC staffs evaluation of the APS reports is enclosed.
Sincerely,
/RA/
Michael T. Markley, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-530
Enclosure:
Safety Evaluation cc w/encl: See next page
March 25, 2008 Mr. Randall K. Edington Executive Vice President Nuclear/
Chief Nuclear Officer Mail Station 7602 Arizona Public Service Company P. O. Box 52034 Phoenix, AZ 85072-2034
SUBJECT:
PALO VERDE NUCLEAR GENERATING STATION, UNIT 3 - RESULTS OF 12TH STEAM GENERATOR TUBE INSPECTION (TAC NO. MD5981)
Dear Mr. Edington:
By letters dated May 4, 2006, and March 23, 2007, Arizona Public Service Company (APS, the licensee) submitted information pertaining to its 2006 steam generator (SG) tube inspections for the Palo Verde Nuclear Generating Station (Palo Verde), Unit 3, Facility Operating License No. NPF-74. These inspections were performed during the 12th refueling outage of Unit 3. The U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with APS concerning the 2006 SG tube inspection results at Palo Verde, Unit 3, and documented the discussions in a letter dated August 23, 2006.
Based on a review of the material provided by APS, the NRC staff concludes that the licensee provided the information required for SG tube inspections by the plant technical specifications.
In addition, the NRC staff did not identify any issues that warrant follow-up at this time. The NRC staffs evaluation of the APS reports is enclosed.
Sincerely,
/RA/
Michael T. Markley, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-530
Enclosure:
Safety Evaluation cc w/encl: See next page DISTRIBUTION PUBLIC LPLIV r/f RidsAcrsAcnw&mMailCenter RidsNrrDirsItsb RidsNrrDorlDpr RidsNrrDorlLpl4 RidsNrrPMMMarkley RidsNrrLAJBurkhardt RidsOgcRp RidsRgn4MailCenter RidsNrrDciCsgb AJohnson, NRR/DCI/CSGB ADAMS Accession No.: ML080840453
(*) SE OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/CSGB/BC NRR/LPL4/BC NAME MMarkley JBurkhardt AHiser (*)
THiltz DATE 3/25/08 3/25/08 11/29/07 3/25/08 OFFICIAL AGENCY RECORD
Palo Verde Nuclear Generating Station cc:
Mr. Steve Olea Arizona Corporation Commission 1200 W. Washington Street Phoenix, AZ 85007 Mr. Douglas Kent Porter Senior Counsel Southern California Edison Company Law Department, Generation Resources P.O. Box 800 Rosemead, CA 91770 Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 40 Buckeye, AZ 85326 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 Chairman Maricopa County Board of Supervisors 301 W. Jefferson, 10th Floor Phoenix, AZ 85003 Mr. Aubrey V. Godwin, Director Arizona Radiation Regulatory Agency 4814 South 40 Street Phoenix, AZ 85040 Mr. Scott Bauer, Director Regulatory Affairs Palo Verde Nuclear Generating Station Mail Station 7636 P.O. Box 52034 Phoenix, AZ 85072-2034 Mr. Dwight C. Mims Vice President Regulatory Affairs and Plant Improvement Palo Verde Nuclear Generating Station Mail Station 7605 P.O. Box 52034 Phoenix, AZ 85072-2034 Mr. Matthew Benac Assistant Vice President Nuclear & Generation Services El Paso Electric Company 340 East Palm Lane, Suite 310 Phoenix, AZ 85004 Mr. John Taylor Public Service Company of New Mexico 2401 Aztec NE, MS Z110 Albuquerque, NM 87107-4224 Mr. Geoffrey M. Cook Southern California Edison Company 5000 Pacific Coast Hwy Bldg D21 San Clemente, CA 92672 Mr. Robert Henry Salt River Project 6504 East Thomas Road Scottsdale, AZ 85251 Mr. Jeffrey T. Weikert Assistant General Counsel El Paso Electric Company Mail Location 167 123 W. Mills El Paso, TX 79901 Mr. Eric Tharp Los Angeles Department of Water & Power Southern California Public Power Authority P.O. Box 51111, Room 1255-C Los Angeles, CA 90051-0100 Mr. Brian Almon Public Utility Commission William B. Travis Building P.O. Box 13326 1701 North Congress Avenue Austin, TX 78701-3326 Ms. Karen O'Regan Environmental Program Manager City of Phoenix Office of Environmental Programs 200 West Washington Street Phoenix AZ 85003
STAFF EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RESULTS OF 12TH STEAM GENERATOR TUBE INSERVICE INSPECTION ARIZONA PUBLIC SERVICE COMPANY, ET AL.
PALO VERDE NUCLEAR GENERATING STATION, UNIT 3 DOCKET NO. STN 50-530
1.0 INTRODUCTION
By letters dated May 4, 2006 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML061310142), and March 23, 2007 (ADAMS Accession No. ML070940084), Arizona Public Service Company (APS, the licensee) submitted information pertaining to its 2006 steam generator (SG) tube inspections for the Palo Verde Nuclear Generating Station (Palo Verde), Unit 3, Facility Operating License No. NPF-74. These inspections were performed during the 12th refueling outage of Unit 3. The U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with APS concerning the 2006 SG tube inspection results at Palo Verde, Unit 3, and documented the discussions in a letter dated August 23, 2006 (ADAMS Accession No. ML062130435).
Palo Verde, Unit 3 has two Combustion Engineering System 80 SGs. There are 11,012 mill-annealed Alloy 600 tubes in each SG. The tubes outside diameters are 3/4 inches with a wall thickness of 0.042 inches. Ferritic stainless steel egg-crate tube supports, diagonal bars, and/or vertical straps support the tubes at various locations. This was the last planned inspection for the current SGs, as they were replaced during the 13th refueling outage during the fall of 2007.
2.0 REGULATORY EVALUATION
The licensee provided the scope, extent, methods, and results of its SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (i.e., tube plugging or repair) taken in response to the inspection findings.
There were two observations to note from review of the licensees 2006 inspection reports:
An 8.30-inch long axial outside diameter stress-corrosion crack was detected in the u-bend region of a row 14 tube. The shallow indication was detected with a rotating probe.
Cold-leg cracking was found at various locations in SG 32. Two support-related indications were identified in SG 32 at the fifth and sixth vertical strap supports. A
small freespan outside diameter stress-corrosion crackwas found in tube R48C159 adjacent to the fourth vertical strap support.
3.0 CONCLUSION
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by their technical specifications. In addition, the NRC staff concludes that there are no technical issues that warrant follow-up action at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
Principal Contributor: A. Johnson Date: March 25, 2008