ML101870676
| ML101870676 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 07/30/2010 |
| From: | Hall J Plant Licensing Branch IV |
| To: | Edington R Arizona Public Service Co |
| Hall, J R, NRR/DORL/LPL4, 301-415-4032 | |
| References | |
| TAC ME3913 | |
| Download: ML101870676 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 July 30, 2010 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 SUB~IECT:
PALO VERDE NUCLEAR GENERATING STATION, UNIT 2 -
SUMMARY
OF THE STAFF'S REVIEW OF THE 2009 STEAM GENERATOR TUBE INSPECTIONS DURING REFUELING OUTAGE 15 (TAC NO. ME3913)
Dear Mr. Edington:
By letter dated April 30, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101310394), Arizona Public Service Company (the licensee),
submitted the results of its 2009 steam generator tube inspections performed during Refueling Outage 15 at Palo Verde Nuclear Generating Station, Unit 2 (PVNGS 2).
The U.S. Nuclear Regulatory Commission staff has completed its review and concludes that the licensee provided the information required by the PVNGS 2 technical specifications. No additional follow-up is required at this time. The staff's review is enclosed. If you have any questions, please contact me at (301) 415-4032 or via e-mail at randy.hall@nrc.gov.
Sincerely, J mes R. Hall, Senior Project Manager lant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-529
Enclosure:
As stated cc w/encl: Distribution via Listserv
STAFF EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RESULTS OF THE 2009 STEAM GENERATOR TUBE INSPECTION PERFORMED DURING REFUELING OUTAGE 15 PALO VERDE NUCLEAR GENERATION STATION, UNIT 2 DOCKET NO. STN 50-529 By letter dated April 30, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101310394), Arizona Public Service Company (the licensee) submitted the results of the steam generator (SG) tube inspections performed at Palo Verde Nuclear Generating Station (PVNGS), Unit 2 during its 2009 refueling outage. This report was submitted in accordance with Technical Specification (TS) 5.6, "Reporting Requirements,"
Section 5.6.8.
PVI\\JGS 2 has two Combustion Engineering System 80 SGs. There are 12,580 thermally treated Alloy 690 tubes in each SG. The tubes have an outside diameter of 0.75 inches and 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.
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, such as tube plugging, taken in response to the inspection findings. The tubes in SGs 21 and 22 were inspected during this outage.
After reviewing the information provided by the licensee, the U.S. Nuclear Regulatory Commission (NRC) staff has the following comments and observations:
The only degradation noted during the examination was wear. It was noted in various support structures, including the batwings.
SUbsequent to sending the report, the licensee clarified that "CCWA" stands for Central Cavity Wear Area and that the tubes preventatively plugged were plugged because of small wear indications that typically would not have been repaired. These tubes are shown on the tubesheet maps in Appendix E of the licensee's report in green and in the legend as "TBP List 2."
Fourteen tubes were plugged in total. Ten were plugged in SG 21, and four were plugged in SG 22. In SG21, two of the ten plugged tubes were plugged due to a possible loose-part indication in the freespan above tube support 08C. No tube wear was associated with this loose part. According to the licensee, this part is most likely an eggcrate wedge that migrated down from partial eggcrate support 09C. Two tubes were stabilized and plugged because of this loose part.
Enclosure
- 2 Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by PVNGS TS Section 5.6.8. In addition, the 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 that inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
July 30, 2010 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 2 -
SUMMARY
OF THE STAFF'S REVIEW OF THE 2009 STEAM GENERATOR TUBE INSPECTIONS DURING REFUELING OUTAGE 15 (TAC NO. IVIE3913)
Dear Mr. Edington:
By letter dated April 30, 2010 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML101310394), Arizona Public Service Company (the licensee),
submitted the results of its 2009 steam generator tube inspections performed during Refueling Outage 15 at Palo Verde Nuclear Generating Station, Unit 2 (PVNGS 2).
The U.S. Nuclear Regulatory Commission staff has completed its review and concludes that the licensee provided the information required by the PVNGS 2 technical specifications. No additional follow-up is required at this time. The staff's review is enclosed. If you have any questions, please contact me at (301) 415-4032 or via e-mail at randy.hall@nrc.gov.
Sincerely,
/raj James R. Hall, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. STN 50-529
Enclosure:
As stated cc w/encl: Distribution via Listserv DISTRIBUTION:
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'II DATE 7/21/10 7/22/10 7/21/10 6/30/10 7/29/10 7/30/10 OFFICIAL RECORD COpy