ML17331A685

Review of the Fall 2016 Steam Generator Tube Inservice Inspection Report for Refueling Outage 27

ML17331A685
Person / Time
Site:	Saint Lucie
Issue date:	12/21/2017
From:	Perry Buckberg Plant Licensing Branch II
To:	Nazar M Florida Power & Light Co
Buckberg P, NRR/DORL/LPL2-2, 415-1447
References
CAC MF9659, EPID L-2017-LLL-0012
Download: ML17331A685 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Decemb~r21, 2017 Mr. Mano Nazar President and Chief Nuclear Officer Nuclear Division Florida Power & Light Co.

Mail Stop EX/JB 700 Universe Blvd.

Juno Beach, FL 33408

SUBJECT:

ST. LUCIE PLANT UNIT NO. 1 - REVIEW OF THE FALL 2016 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT FOR REFUELING OUTAGE 27 (CAC MF9659; EPID L-2017-LLL-0012)

Dear Mr. Nazar:

By letter dated April 27, 2017 (Agencywide Documents Access and Management System Accession No. ML17117A334), Florida Power & Light Company (the licensee) submitted information summarizing the results of the fall 2016 steam generator tube inspections at St. Lucie Plant Unit No. 1. These inspections were performed during Refueling Outage 27 in accordance with Technical Specification Section 6.8.4.1.

The Nuclear Regulatory Commission staff has completed its review of the information provided, concludes that the licensee provided the information required by their technical specifications, and that no followup is required at this time. The staff's review of the report is enclosed.

27//#.*

Perry H. Buckberg, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-335

Enclosure:

As stated cc: ListServ

REVIEW OF THE 2016 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT ST. LUCIE PLANT UNIT NO. 1 DOCKET NO. 50-335 CAC NO. MF9659; EPID L-2017-LLL-0012 By letter dated April 27, 2017 (Agencywide Documents Access and Management System Accession No. ML17117A334}, Florida Power & Light Company (the licensee) submitted information summarizing the results of the fall 2016 steam generator (SG) tube inspections at St. Lucie Plant Unit No. 1. These inspections were performed during Refueling Outage (RFO) 27.

St. Lucie Unit 1 has two replacement SGs designed and fabricated by Babcock and Wilcox International that were installed in 1997. Each SG has 8,523 thermally treated Alloy 690 tubes with a nominal outside diameter of 0.75 inches and a nominal wall thickness of 0.045 inches.

The tubes are arranged in a triangular pattern with a pitch of approximately 1.0 inch. During manufacturing, the tubes were hydraulically expanded at each end for the full depth of the tubesheet. The tubesheet is 21.5-inches thick; with the cladding, the tubesheet is 21.875-inches thick. The tubes are supported by lattice grid tube supports and fan bars; the lowest fan bar is also referred to as a collector bar since all other fan bars connect to it. All supports are constructed from Type 410 stainless steel. During manufacturing, the U-bend region of the tubes in rows 1 through 20 were stress relieved after bending. The smallest U-bend radius occurs in row 3 and is 3.905 inches. The row 1 U-bend radius measures 4.272 inches.

This was the sixth inservice inspection for the replacement SGs. At the end of RFO 27 in 2016, the replacement SGs had accumulated 198.18 effective full-power months of operation.

The licensee provided the scope, extent, methods, and results of their SG tube inspections in the April 27, 2017, inspection report in accordance with their technical specification (TS) requirements. In addition, the licensee described corrective actions, such as tube plugging, taken in response to the inspection findings.

Based on its review of the report submitted, the Nuclear Regulatory Commission staff has the following observation:

• No tube wear exceeded the TS plugging limit of 40-percent through-wall. Some tubes were plugged to support an operational assessment until the next planned primary-side inspection in RFO 30. No primary-side inspections are planned for RFO 28 or 29.

Based on a review of the information provided by the licensee, the staff concludes that the licensee provided the information required by their TSs. The SG tube inspections at St. Lucie Unit 1 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.

Enclosure

M. Nazar

SUBJECT:

ST. LUCIE PLANT UNIT NO. 1 - REVIEW OF THE FALL 2016 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT FOR REFUELING OUTAGE 27 (CAC MF9659; EPID L-2017-LLL-0012) DATED DECEMBER 21, 2017 DISTRIBUTION:

PUBLIC RidsACRS_MailCTR Resource AHuynh, NRR RidsNrrPMStLucie Resource RidsNrrDorlLpl2-2 Resource AJohnson, NRR RidsNrrLABClayton Resource RidsRgn2Mai1Center Resource PKlein, NRR RidsNrrDlmrMccb Resource LPL2-2 R/F ADAMS Access1on Num ber: ML17331A685 *b>Ye-ma,*1 OFFICE D0RL/LPL2-2/PM D0RL/LPL2-2/LA DLMR/MCCB/BC* D0RL/LPL2-2/BC D0RL/LPL2-2/PM NAME PBuckberg BClayton SBloom UShoop PBuckberg DATE 12/11/17 12/07/17 11/13/17 12/20/17 12/21/17 OFFICIAL RECORD COPY