ML20149K626

NRR E-mail Capture - Turkey Point Unit 4 - Request for Additional Information Concerning 2019 Steam Generator Tube Inspections

ML20149K626
Person / Time
Site:	Turkey Point
Issue date:	05/27/2020
From:	Ellen Brown NRC/NRR/DORL/LPL2-2
To:	Hanek O, Mack J Florida Power & Light Co
References
L-2019-LRO-0103
Download: ML20149K626 (3)

Text

From: Brown, Eva Sent: Wednesday, May 27, 2020 12:03 PM To: Mack, Jarrett; Hanek, Olga Cc: 'Hess, Robert'

Subject:

ACTION: Turkey Point Unit 4 - Request for Additional Information Concerning 2019 Steam Generator Tube Inspections (EPID: L-2019-LRO-0103)

Attachments: 0103 Turkey Point U4 RAI.docx Olga/Jarrett, By letter dated September 25, 2019 (Agencywide Documents Access and Management System Accession No. ML19268B738), Florida Power & Light Company (FPL) submitted information summarizing the results of the spring 2019 steam generator (SG) inspections performed at Turkey Point Nuclear Generating Unit 4. To complete its review of the inspection report, the NRC staff requests the following additional information contained in the attached.

On May 20, 2020, it was indicated that FPL would be able to respond within 30 days of this notification.

Eva Brown Senior Project Manager, Turkey Point Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Telephone: (301) 415-2315 Fax: (301) 415-1222

Hearing Identifier: NRR_DRMA Email Number: 609 Mail Envelope Properties (MN2PR09MB5274D3E159AB29616BE40B5CEFB10)

Subject:

ACTION: Turkey Point Unit 4 - Request for Additional Information Concerning 2019 Steam Generator Tube Inspections (EPID: L-2019-LRO-0103)

Sent Date: 5/27/2020 12:03:18 PM Received Date: 5/27/2020 12:03:00 PM From: Brown, Eva Created By: Eva.Brown@nrc.gov Recipients:

"'Hess, Robert'" <Robert.Hess@fpl.com>

Tracking Status: None "Mack, Jarrett" <Jarrett.Mack@fpl.com>

Tracking Status: None "Hanek, Olga" <Olga.Hanek@fpl.com>

Tracking Status: None Post Office: MN2PR09MB5274.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 831 5/27/2020 12:03:00 PM 0103 Turkey Point U4 RAI.docx 32462 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

REQUESTS FOR ADDITIONAL INFORMATION SPRING 2019 STEAM GENERATOR TUBE INSPECTION REPORT TURKEY POINT NUCLEAR PLANT UNIT 4 DOCKET NO. 50-251 By letter dated September 25, 2019 (Agencywide Documents Access and Management System Accession No. ML19268B738), Florida Power & Light Company (FPL) submitted information summarizing the results of the spring 2019 steam generator (SG) inspections performed at Turkey Point Nuclear Generating Unit 4. These inspections were performed during refueling outage (RFO) 31. Technical Specification (TS) Section 6.9.1.8 requires that a report be submitted within 180 days after the initial entry into hot shutdown (MODE 4) following completion of an inspection of the SGs performed in accordance with TS Section 6.8.4.j, which requires that a SG Program be established and implemented to ensure SG tube integrity is maintained.

To complete its review of the inspection report, the U.S. Nuclear Regulatory Commission staff requests the following additional information:

1. Tube R38C58 in SG-B was plugged due to atypical anti-vibration bar (AVB) wear growth rate history. FPL reported indication growth rates of 8 percent and 10 percent through-wall at two AVB locations over the last two operating cycles.

Provide any details on what may have contributed to the atypical AVB wear growth rates. In addition, compare the observed AVB wear growth rates for this tube with the 95th percentile AVB wear growth rate assumed in the Cycles 29 and 30 operational assessment; and discuss whether FPL adjusted the projected AVB wear growth rates for the upcoming operating period.

2. A newly identified foreign object (FO) shaped like a button-head bolt was identified in SG-B that could not be removed because it was fixed in place between four adjacent tubes. FPL reported that the object appears to have been in place since the SG was manufactured.

Dent signals, with no associated degradation just above the top of tubesheet, were reported for the four adjacent tubes.

Discuss whether the dent signals in the four adjacent tubes have been present since SG-B was placed into service or whether the dent signals were newly identified during RFO31. If there is a history of dent signals in the four adjacent tubes at those locations, then discuss whether there have been any historical possible loose part signals in those tubes at those locations.

3. FPL reported that ultrasonic testing thickness measurements identified external wall thinning on the feedring in SG-B that appears to have been caused by impingement when feedwater discharges from the neighboring j-tube. FPL further stated that the external wall thinning of the feedring was entered in the corrective action program and that repairs were performed in RFO31.

Describe the repairs that were performed to address the external wall thinning of the feedring.