ML24072A238

Review of the Fall 2023 Steam Generator Tube Inspections During Refueling Outage No. 33

ML24072A238
Person / Time
Site:	Turkey Point
Issue date:	03/20/2024
From:	Michael Mahoney Plant Licensing Branch II
To:	Coffey B Florida Power & Light Co
Mahoney, M NRR/DORL 415-3867
References
EPID L-2023-LRO-0078
Download: ML24072A238 (4)

Text

March 20, 2024

Bob Coffey Executive Vice President, Nuclear and Chief Nuclear Officer Florida Power & Light Company 700 Universe Blvd.

Mail Stop: EX/JB Juno Beach, FL 33408

SUBJECT:

TURKEY POINT NUCLEAR GENERATING UNIT NO. 3 - REVIEW OF THE SPRING 2023 STEAM GENERATOR TUBE INSPECTIONS DURING REFUELING OUTAGE NO. 33 (EPID L-2023-LRO-0078)

Dear Bob Coffey:

By letter dated October 26, 2023, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23299A122), Florida Power and Light Company (the licensee),

submitted information to the U.S. Nuclear Regulatory Commission (NRC) summarizing the results of the spring 2023 steam generator (SG) tube inspections performed at the Turkey Point Nuclear Generating Unit No. 3 (Turkey Point 3). The inspections were performed during refueling outage no. 33 (U3R33).

The NRC staff has completed its review of t he submittal and concludes that the licensee provided the information required by Turkey Point 3, Technical Specification 6.9.1.8, Steam Generator Tube Inspection Report. In addition, the NRC staff concludes that there are no technical issues that warrant follow-up actions at this time. Enclosed is the NRC staffs review of the Turkey Point 3 SG tube inspection report for U3R33.

B. Coffey

If you have any questions, please contact me at 301-415-3867 or Michael.Mahoney@nrc.gov.

Sincerely,

/RA/

Michael Mahoney, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket No. 50-250

Enclosure:

Review of the Steam Generator Tube Inspection Report

cc: Listserv REVIEW OF THE SPRING 2023 (U3R33) STEAM GENERATOR

TUBE INSPECTION REPORT

FLORIDA POWER & LIGHT COMPANY

TURKEY POINT NUCLEAR GENERATING UNIT NO. 3

DOCKET NO. 50-250

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated October 26, 2023, (Agencywide Documents Access and Managem ent Systems (ADAMS) Accession No. ML23299A122), Florida Power and Light Company (the licensee) submitted information summarizing the results of the spring 2023 steam generator (SG) inspections performed at Turkey Point Nuclear Generating Station, Unit 3 (Turkey Point 3). These inspections were performed during refueling outage (RFO) 33 (U3R33).

Turkey Point 3 contains three Westinghouse Model 44F SGs, which were placed in service in 1982. Each SG contains 3,214 thermally treated Alloy 600 tubes with a nominal outside diameter of 0.875 inches and a nominal wall-thickness of 0.050 inches. The straight length of the tubes is supported by six stainless steel quatrefoil broached-hole tube support plates (TSPs). Each SG has one stainless steel drilled-hole flow distribution baffle between the tubesheet secondary face and the bottom TSP. The tubes are supported in the U-bend region by two sets of chrome-plated Alloy 600 V-shaped anti-vibration bars. The U-bend section of Rows 1-8 (small radius) was thermally stress relieved after bending to reduce residual stress.

The licensee provided the scope, extent, methods, and results of its SG tube inspections. In addition, the licensee described corrective actions, such as tube plugging, taken in response to the inspection findings. After reviewing the information provided by the licensee, the NRC staff has the following comments/observations:

SG tube inspections were not originally planned for RFO 33. Discovery of an outside-diameter stress-corrosion cracking indication in the U-bend region of a Row 1 tube during RFO 32 required a follow-up inspection for this degradation mechanism in RFO 33. The inspection scope during RFO 33 included the U-bend portion of Tubes in Rows 1, 2, 9, and 10, dents and dings greater than 5 volts in the U-bends of Rows 1 to 10, and special interest exams, as needed. In addition, all tube plugs and the channel head bowl components were visually inspected.

No stress-corrosion cracking was detected during the tube inspections. Two tubes were plugged. One tube, without degradation, was plugged due to difficulty obtaining eddy current data at one location. Another tube was preventatively plugged due to foreign object wear.

Based on a review of the information provi ded, the NRC staff concludes that the licensee provided the information required by their tec hnical specifications. In addition, the NRC staff concludes that there are no technical issues that warrant follow-up action currently, 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.

Enclosure

ML24072A238 OFFICE DORL/LPL2-2/PM DORL/LPL2-2/LA DNRL/NCSG/BC NAME MMahoney ABaxter SBloom DATE 03/12/2024 03/18/2024 03/11/2024 OFFICE DORL/LPL2-2/BC DORL/LPL2-2/PM NAME DWrona MMahoney DATE 03/19/2024 03/20/2024