ML22181A056

NRR E-mail Capture - Request for Additional Information - Turkey Point U3 Sgtir (L-2022-LRO-0070)

ML22181A056
Person / Time
Site:	Turkey Point
Issue date:	06/30/2022
From:	Michael Mahoney NRC/NRR/DORL/LPL2-2
To:	Mack J Florida Power & Light Co
References
L-2022-LRO-0070
Download: ML22181A056 (3)

Text

From: Mahoney, Michael Sent: Thursday, June 30, 2022 7:46 AM To: Mack, Jarrett

Subject:

Request for Additional Information - Turkey Point U3 SGTIR (L-2022-LRO-0070)

Jarrett, By letter dated May 6, 2022 (ML22126A104), Florida Power & Light Company submitted information summarizing the results of the fall 2021 steam generator (SG) inspections performed at Turkey Point Nuclear Generating Unit 3. These inspections were performed during refueling outage 32 (TP3-32). 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.

In order to complete its review, the U.S. Nuclear Regulatory Commission staff requests additional information. Please provide your response to the following requests for additional information (RAIs) within 45 days of the date of this correspondence.

RAI-1

Tubes Row 33, Column 43 (R33C43) and R34C31 in SG-C were plugged due to unusually high anti-vibration bar (AVB) wear growth during TP3-32. The wear indications at AVB 2 (AV2) and AV3 in tube R33C43 appear to have grown in depth by 5 percent through-wall (TW) and 7 percent TW, respectively, since TP3-27 (spring 2014, ML14302A079). In addition, the wear indications at AV2 and AV3 in Tube R34C31 appear to have both grown in depth by 3 percent TW since TP3-27. Therefore, it is unclear to the staff on how AVB wear growth is classified as unusually high.

Tube R35C49 in SG-C was plugged due to AVB wear greater than the 40 percent TW plugging criterion in the TS during TP3-32. The wear indications at AV3 and AV4 in this tube appear to have grown in depth by 24 percent TW and 19 percent TW, respectively, since TP3-27.

Please provide the following:

a. The parameters used for classifying AVB wear growth as unusually high. In addition, include the AVB growth rates (i.e., the means and standard deviations of the AVB growth rates) in the three SGs.

b. Any insights on what may have contributed to the AVB wear growth, such as deposit loading or thermal hydraulic behavior, in Tube R35C49.

c. A comparison of the observed AVB wear growth rates for Tubes R33C43, R34C31, and R35C49 with the 95th percentile AVB wear growth rate assumed in the Cycles 30 and 31 operational assessments; and whether adjustments were required to the projected AVB wear growth rates for the upcoming operating period.

RAI-2

Tube R18C87 in SG-B was preventively plugged due to a volumetric (VOL) indication in the freespan. This VOL indication was reported to be 23 percent TW, which fell below the condition

monitoring limit curve, and met the acceptance criteria for burst and leakage integrity. The fall 2021 report states that eddy current analysis code VOL is used to report freespan wear in TP3-32. No indication was reported in Tube R18C87 during TP3-29 (spring 2017, ML17325A998), and the fall 2021 report states that the newly identified foreign object (small-grade wire) was removed from SG-B.

Please provide any insights on what may have contributed to the VOL indication in the freespan of Tube R18C87.

Once this email is added to ADAMS, I will provide the accession number for your reference.

If you have any questions, please contact me.

Thanks Mike Mahoney Project Manager, LPL2-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Desk: (301)-415-3867 Mobile: (301)-250-0450 Email: Michael.Mahoney@nrc.gov

Hearing Identifier: NRR_DRMA Email Number: 1692 Mail Envelope Properties (BLAPR09MB6017AB4974865F8BD06DF110E5BA9)

Subject:

Request for Additional Information - Turkey Point U3 SGTIR (L-2022-LRO-0070)

Sent Date: 6/30/2022 7:46:24 AM Received Date: 6/30/2022 7:46:30 AM From: Mahoney, Michael Created By: Michael.Mahoney@nrc.gov Recipients:

"Mack, Jarrett" <Jarrett.Mack@fpl.com>

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