ML14013A247

St. Lucie Plant, Unit 2 - Review of the 2012 Refueling Outage Steam Generator Tube Inservice Inspection Report (TAC No. MF1786)

ML14013A247
Person / Time
Site:	Saint Lucie
Issue date:	01/27/2014
From:	Lingam S P Plant Licensing Branch II
To:	Nazar M Florida Power & Light Co
Lingam S P
References
TAC MF1786
Download: ML14013A247 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Mano Nazar Executive Vice President and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420 January 27, 2014

SUBJECT:

ST. LUCIE PLANT, UNIT 2-REVIEW OF THE 2012 REFUELING OUTAGE STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT (TAC NO. MF1786)

Dear Mr. Nazar:

By letter dated May 6, 2013, as supplemented by letter dated November 26, 2013, Florida Power and Light Company (the licensee) submitted information summarizing the results of the fall 2012 steam generator tube inspection report, for the twentieth Refueling Outage (fall 2012) in accordance with Technical Specification (TS) Section 6.9.1.12 for St. Lucie Plant, Unit 2. In addition to the above report, additional information concerning the fall 2012 inspections was summarized by the Nuclear Regulatory Commission (NRC) staff in documents dated April4 and April 11, 2013. The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by its TSs and that no additional followup is required at this time. The NRC staff's review of the report is enclosed. Docket No. 50-389

Enclosure:

Inspection Summary Report cc w/encl: Distribution via ListServ Sincerely, Siva P. Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation REVIEW OF THE FALL 2012 REFUELING OUTAGE STEAM GENERATOR TUBE INSPECTION REPORT FLORIDA POWER AND LIGHT COMPANY ST. LUCIE PLANT. UNIT 2 DOCKET NO. 50-389 By letter dated May 6, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13141 A479), as supplemented by letter dated November 26, 2013 (ADAMS Accession No. ML 13338A582), Florida Power and Light Company (the licensee) submitted information summarizing the results of the fall 2012 steam generator (SG) tube inspections at St. Lucie Plant (St. Lucie), Unit 2. These inspections were performed during the twentieth refueling outage (RFO). In addition to the above report, additional information concerning the fall 2012 inspections was summarized by the Nuclear Regulatory Commission (NRC) staff in documents dated April 4, 2013 (ADAMS Accession No. ML 13084A030), and April 11, 2013 (ADAMS Accession No. ML 13094A174). St. Lucie, Unit 2 has two Model 86/19TI replacement SGs that were manufactured by AREVA and installed in December 2007. Each SG has 8,999 thermally treated Alloy 690 tubes with a nominal outside diameter of 0.75 inches and a nominal wall thickness of 0.043 inches. During manufacturing, all tubes were hydraulically expanded at both ends over the full depth of the tubesheet. The tubesheet was drilled on a triangular pitch with 1.0-inch spacing, center-to-center. The radius of the row 1 U-bends is 4.134 inches. The U-bends in rows 1 through 15 were stress relieved after bending. Seven Type 410 stainless steel support plates (each 1.181 inches thick with broached trefoil holes) support the vertical section of the tubes. Four sets of anti-vibration bars (AVBs) (each 0.112 inches thick and made from Type 405 stainless steel) support the U-bend section of the tubes. This was the third inservice inspection for the replacement SGs. At the end of RFO 20 in fall 2012, the replacement SGs had accumulated 46.40 effective full power months of operation. The licensee provided the scope, extent, methods, and results of their 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 both SGs were inspected during this refueling outage. Based on its review of the reports submitted, the NRC staff has the following observations and comments:

• The only service induced indications detected were wear at the AVBs (including at the tips of the AVBs in row 69), tube support plates, and the support/positioning device. The support/positioning device supports the AVB structure, is located on the outer periphery of the tube bundle, and it contacts numerous tubes on the extrados. All tubes with indications at the support/positioning device were plugged. Enclosure

• Approximately 11,518 indications of wear at the AVBs were detected (7,485 in SG A and 4,033 in SG B). Of these indications, the number of new indications was 1,623 in SG A and 1,070 in SG B. The average growth rate per effective full power year (2.2 percent in SG A and 0.6 percent in SG B) continues to decline.

• The licensee is implementing a power uprate in the next cycle of operation (Cycle 20) and incorporated a wear rate increase of 24 percent in their operational assessment to account for the effects of the power uprate. 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 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 inspection results appear to be consistent with industry operating experience at similarly designed and operated units. The NRC staff notes, however, that the number of wear indications is much greater than the number of wear indications found at other AREVA SGs of similar age.

Mr. Mano Nazar Executive Vice President and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420 January 27, 2014

SUBJECT:

ST. LUCIE PLANT, UNIT 2-REVIEW OF THE 2012 REFUELING OUTAGE STEAM GENERA TOR TUBE INSERVICE INSPECTION REPORT (TAC NO. MF1786)

Dear Mr. Nazar:

By letter dated May 6, 2013, as supplemented by letter dated November 26, 2013, Florida Power and Light Company (the licensee) submitted information summarizing the results of the fall 2012 steam generator tube inspection report, for the twentieth Refueling Outage (fall 2012) in accordance with Technical Specification (TS) Section 6.9.1.12 for St. Lucie Plant, Unit 2. In addition to the above report, additional information concerning the fall 2012 inspections was summarized by the Nuclear Regulatory Commission (NRC) staff in documents dated April 4 and April 11, 2013. The NRC staff has completed its review of these reports and concludes that the licensee provided the information required by its TSs and that no additional followup is required at this time. The NRC staff's review of the report is enclosed. Docket No. 50-389

Enclosure:

Inspection Summary Report Sincerely, IRA/ Siva P. Lingam, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation cc w/encl: Distribution via ListServ DISTRIBUTION: PUBLIC LPL2-2 R/F RidsNrrPMStLucie Resource RidsNrrLABCiayton Resource RidsAcrsAcnw_MaiiCTR Resource RidsNrrDoriLpl2-2 Resource RidsRgn2Mai1Center Resource ADAMS A ccess1on N ML 14013A247 o.: !OFFICE LPL2-2/PM LPL2-2/LA ESGB/BC* NAME Slingam BCiayton GKulesa DATE 1/15/14 1/15/14 12/18/13 OFFICIAL AGENCY COPY RidsNrrDeEsgb Resource AJohnson, NRR KKarwoski, NRR *b >>_y_memo LPL2-2/BC JQuichocho 1/27/14