ML25014A114
| ML25014A114 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 01/14/2025 |
| From: | Luke Haeg Plant Licensing Branch II |
| To: | Osting S Vistra Operating Co. (VistraOpCo) |
| References | |
| L-2024-LRO-0039 | |
| Download: ML25014A114 (4) | |
Text
From:
Luke Haeg Sent:
Tuesday, January 14, 2025 9:18 AM To:
Osting, Steven Cc:
Subject:
Davis-Besse - RCI re: 1R23 SG tube inspection report (EPID L-2024-LRO-0039)
Attachments:
Final RCI L-2024-LRO-0039.pdf
Dear Steven Osting,
By letter (L-24-030) dated September 11, 2024 (Agencywide Documents Access and Management System Accession No. ML24255A803), Vistra Operations Company LLC (Vistra OpCo, the licensee) submitted information summarizing the results of steam generator (SG) tube inspections performed during the spring 2023 refueling outage (1R23) at Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse).
The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your report and has identified an area where confirmatory information is needed to complete its review.
A request for confirmatory information (RCI) is attached. A draft RCI was sent to you to ensure it was understandable and a clarification call was held on January 13, 2025. Based on the discussion, a response from Vistra OpCo to the attached RCI is requested within 30 days from the date of this email (i.e., by February 14, 2025). If circumstances result in the need to revise the requested response date, please contact me at (301) 415-0272 or lucas.haeg@nrc.gov. Thank you.
Luke Haeg Project Manager NRR/DORL/LPL II-2 U.S. Nuclear Regulatory Commission 301-415-0272
Hearing Identifier:
NRR_DRMA Email Number:
2699 Mail Envelope Properties (DM8PR09MB640757C22B30640AFC64D91F98182)
Subject:
Davis-Besse - RCI re 1R23 SG tube inspection report (EPID L-2024-LRO-0039)
Sent Date:
1/14/2025 9:18:28 AM Received Date:
1/14/2025 9:18:00 AM From:
Luke Haeg Created By:
Lucas.Haeg@nrc.gov Recipients:
"Ilka Berrios" <Ilka.Berrios@nrc.gov>
Tracking Status: None "Osting, Steven" <Steven.Osting@vistracorp.com>
Tracking Status: None Post Office:
DM8PR09MB6407.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1232 1/14/2025 9:18:00 AM Final RCI L-2024-LRO-0039.pdf 94780 Options Priority:
Normal Return Notification:
No Reply Requested:
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REQUEST FOR CONFIRMATORY INFORMATION REGARDING THE 1R23 STEAM GENERATOR TUBE INSPECTION REPORT EPID L-2024-LRO-0039 VISTRA OPERATIONS COMPANY LLC DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-346 INTRODUCTION By letter (L-24-030) dated September 11, 2024 (Agencywide Documents Access and Management System Accession No. ML24255A803), Vistra Operations Company LLC (Vistra OpCo, the licensee) submitted information summarizing the results of steam generator (SG) tube inspections performed during the spring 2023 refueling outage (1R23) at Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse).
The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your report and has identified areas where confirmatory information is needed to complete its review.
REGULATORY BASIS Davis-Besse Technical Specification (TS) 5.6.6 requires that a report shall be submitted within 180 days after the initial entry into MODE 4 [hot shutdown] following completion of an inspection
[of the SGs] performed in accordance with the [Technical] Specification 5.5.8, "Steam Generator (SG) Program." TS 5.5.8 requires, in part, that a SG Program be established and implemented to ensure SG tube integrity is maintained.
INFORMATION REQUESTED Request for Confirmatory Information (RCI)
Issue Davis-Besse Technical Specification (TS) 5.6.6.e requires reporting of the number of tubes plugged during the inspection outage for each degradation mechanism.
During Davis-Besses 2022 refueling outage (1R22), the licensee detected proximity indications and as a result, plugged 28 tubes (16 in SG 2A and 12 in SG 1B). The licensee did not report the plugging of these tubes in the SG tube inspection report (ML22272A497), presumably because a proximity indication is not a degradation mechanism. The licensee provided the information regarding the plugged tubes with proximity indications in their response (ML23060A077) to a request for additional information (ML23033A032) from the NRC staff.
In Davis-Besses 1R23 SG tube inspection report (ML24255A803), the licensee reported the total number of plugged tubes in each SG but did not specify the number of preventatively plugged tubes in 1R23. While this non-reporting was compliant with the reporting requirements of TS 5.6.6.e (reporting of the number of tubes plugged during the inspection outage for each degradation mechanism), the NRC staff cannot make assumptions about the number of plugged tubes for non-degradation mechanisms, so the numbers of preventatively plugged tubes should also specifically be reported.
Request To complete their review of the SG tube inspections performed during the spring 1R23 at Davis-Besse, as attached to ML24255A803, the NRC staff requests that the licensee confirm whether the following statement is correct:
During 1R23, there were 5 tubes preventively plugged in SG 2A due to proximity indications, and 12 tubes preventively plugged in SG 1B due to proximity indications.