ML121290674
| ML121290674 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 05/22/2012 |
| From: | Balwant Singal Plant Licensing Branch IV |
| To: | Flores R Luminant Generation Co |
| Singal, Balwant, 415-3016, NRR/DORL/LPL4 | |
| References | |
| TAC ME7345 | |
| Download: ML121290674 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 22,2012 Mr. Rafael Flores Senior Vice President and Chief Nuclear Officer Attention: Regulatory Affairs Luminant Generation Company LLC P.O. Box 1002 Glen Rose, TX 76043
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT, UNIT 2 - REVIEW OF THE 2011 STEAM GENERATOR TUBE INSPECTIONS PERFORMED DURING REFUELING OUTAGE 12 (TAC NO. ME7345)
Dear Mr. Flores:
By letter dated October 12, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML11306A012), as supplemented by letter dated April 10, 2012 (ADAMS Accession No. ML12109A051), Luminant Generation Company LLC (the licensee) submitted information summarizing the results of the 2011 steam generator tube inspections performed during refueling outage 12 at Comanche Peak Nuclear Power Plant (CPNPP), Unit 2, for U.S. Nuclear Regulatory Commission (NRC) staff review. The licensee previously participated in a conference call with the NRC staff on April 14, 2011, to discuss the results of these inspections and the results of the discussions were summarized in a letter dated May 23, 2011 (ADAMS Accession No. ML111400148).
The NRC staff has completed its review of the submittal and concludes that the licensee provided the information required by the CPNPP, Unit 2, technical specifications. No additional follow-up is required at this time. The results of the NRC staff's review and observations are enclosed.
R. Flores
- 2 If you have any questions, please contact me at (301) 415-3016 or via e-mail at balwant.singal@nrc.gov.
Sincerely,
~a~i, s~ioJ~ager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-446
Enclosure:
As stated cc w/encl: Distribution via Listserv
OFFICE OF THE NUCLEAR REACTOR REGULATION REVIEW OF THE RESULTS OF 2011 STEAM GENERATOR TUBE INSPECTIONS PERFORMED DURING REFUELING OUTAGE 12 COMANCHE PEAK NUCLEAR POWER PLANT. UNIT 2 DOCKET NO. 50-446 By letter dated October 12, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML11306A012), as supplemented by letter dated April 10, 2012 (ADAMS Accession No. ML12109A051), Luminant Generation Company LLC (the licensee) submitted information summarizing the results of the 2011 steam generator (SG) tube inspections performed during refueling outage 12 at Comanche Peak Nuclear Power Plant (CPNPP), Unit 2, for U.S. Nuclear Regulatory Commission (NRC) staff review. The licensee previously participated in a conference call with the NRC staff on April 14, 2011, to discuss the results of these inspections and the results of the discussions were summarized in a letter dated May 23, 2011 (ADAMS Accession No. ML111400148).
CPNPP, Unit 2, has four Westinghouse Model D5 SGs. Each SG contains 4,570 thermally treated Alloy 600 tubes. Each tube has a nominal outside diameter of 0.750 inches and a nominal wall thickness of 0.043 inches. The tubes were hydraulically expanded at both ends for the full depth of the tubesheet and are supported by a number of Type 405 stainless steel supports with quatrefoil-shaped holes.
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 all four SGs were inspected during the CPNPP, Unit 2, refueling outage 12. A total of three tubes (0.02 percent of the total number of tubes) were plugged for wear at anti-vibration bar (AVB) locations. The licensee stated that no new degradation mechanisms were reported.
Based on the review of the information provided in letter dated October 12, 2011, as supplemented by letter April 10, 2012, the NRC staff has the following comments/observations:
The upper bundle inspection results of SG 4 showed that the quatrefoil holes remained open and free of significant deposits, with slightly more deposit formation noted on the hot-leg than the cold-leg.
The acceptance limits used in the conditioning monitoring and operational assessment were provided in the licensee's letter dated October 12, 2011.
The NRC staff concludes that the licensee provided the information required by the 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 that inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
Enclosure
R. Flores
- 2 If you have any questions, please contact me at (301) 415-3016 or via e-mail at balwant.singal@nrc.gov.
Sincerely,
/ra!
Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-446
Enclosure:
As stated cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC RidsNrrPMComanchePeak Resource LPLIV Reading RidsNrrLAJBurkhardt Resource RidsAcrsAcnw_MailCTR Resource RidsOgcRp Resource RidsNrrDeEsgb Resource RidsRgn4MailCenter Resource RidsNrrDorlDpr Resource AJohnson, NRRIDE/ESGB RidsNrrDorlLpl4 Resource KKarwoski, NRRIDE/ESGB ADAMS Accession No. ML121290674 NRRlLPL4/PM NRR/LPL4/LA NRR/DE/ESGBI BSingal JBurkhardt GKulesa*
5/9/12 5/4/12 OFFICIAL AGENCY RECORD