ML18095A899

Review of the Spring 2017 Steam Generator Tube Inspection Report

ML18095A899
Person / Time
Site:	Point Beach
Issue date:	04/20/2018
From:	Chawla M L Plant Licensing Branch III
To:	Coffey R Point Beach
Chawla M L
References
EPID: L-2017-LRO-0033
Download: ML18095A899 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Robert Craven General Plant Manager NextEra Energy Point Beach, LLC 6610 Nuclear Road Two Rivers, WI 54241 April 20, 2018

SUBJECT:

POINT BEACH NUCLEAR PLANT, UNIT 2 -REVIEW OF THE SPRING 2017 STEAM GENERATOR TUBE INSPECTION REPORT (EPID: L-2017-LR0-0033)

Dear Mr. Craven:

By letter dated September 21, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 17264A354), NextEra Energy Point Beach LLC (the licensee) submitted information summarizing the results of the Spring 2017 steam generator inspections performed at the Point Beach Nuclear Plant, Unit 2. The U.S. Nuclear Regulatory Commission (NRC) staff has completed its review of the information provided and concludes that the licensee provided the information required by their technical specifications, and that no follow-up is required at this time. The NRC staff's review of the report is enclosed.

Docket Nos. 50-266 and 50-301

Enclosure:

Staff Evaluation cc: ListServ Sincerely, Mahesh L. Chawla, Project Manager Plant Licensing Branch Ill Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation POINT BEACH NUCLEAR PLANT, UNIT 2 REVIEW OF SPRING 2017 STEAM GENERATOR TUBE INSPECTION REPORT DOCKET NUMBER 50-301 By letter dated September 21, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 17264A354), NextEra Energy Point Beach, LLC (the licensee) submitted information summarizing the results of the spring 2017 steam generator (SG) inspections performed at the Point Beach Nuclear Plant (Point Beach), Unit 2. Point Beach, Unit 2, has two recirculating SGs designed and fabricated by Westinghouse.

The model Delta 47F SGs were put into service in 1997 during refueling outage (RFO) 22. Each SG has 3,499 thermally treated Alloy 690 tubes that have a nominal 0.875-inch outside diameter and a nominal wall thickness of 0.050 inch. The tubes are arranged in a triangular pattern, were hydraulically expanded at each end for the full depth of the tubesheet.

The tubesheet is 22.4 inches thick including the cladding.

The tubes are supported by a flow distribution baffle, support plates, and anti-vibration bars (AVBs) and are constructed from Type 405 stainless steel. The tube support plates (TSPs) are 1.125 inches thick and have foil shaped holes through which the tubes pass. The U-bend region of the tubes in rows 1 through 14 received a stress relieving thermal treatment after bending. The smallest U-bend radius is 3.25 inches. The licensee provided the scope, extent, methods, and results of their SG tube inspections in the document referenced above. In addition, the licensee described corrective actions, such as tube plugging that was taken in response to the inspection findings.

Based on the review of the information provided, the U.S. Nuclear Regulatory Commission (NRC) staff has the following observations and comments:

• At the completion of Unit 2, Cycle 35, the replacement SGs had accumulated 17.1 Effective Full Power Years (EFPY) and were completed in the second inspection in the second sequential inspection period.

• The only degradation mechanisms detected were mechanical wear at AVBs and at broached TSPs. No tubes were plugged during RFO 35. No tubes in SG A were plugged and four tubes in SG B were plugged. 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 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 the inspection results appear to be consistent with industry operating experience at similarly and operated units. Enclosure

SUBJECT:

POINT BEACH NUCLEAR PLANT, UNIT 2 -REVIEW OF THE SPRING 2017 STEAM GENERATOR TUBE INSPECTION REPORT (EPID: L-2017-LR0-0033)

DATED APRIL 20, 2018 DISTRIBUTION:

PUBLIC LPL3 r/f RidsNrrDorlLpl3Resource RidsNrrPMPointBeach Resource RidsOgcRp Resource RidsNsirDpr Resource RidsAcrs_MailCTR Resource RidsNrrDorlDpr Resource RidsRgn3MailCenter Resource RidsNrrLASRohrer Resource Paul Kline, NRR Andrew Johnson, NRR Alan Huynh, NRR ADAMS Accession No.: ML 18095A899 OFFICE D0RL/LPL3/PM D0RL/LPL3/

LA NAME MChawla SRohrer DATE 4/20/18 4/9/18 NRR/DMLR/

MCCB/BC MYoder /f/SBloom 2/26/18 OFFICIAL RECORD D0RL/LPL3/BC D0RL/LPL3/PM DWrona MChawla 4/20/18 4/20/18