ML25017A282
| ML25017A282 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 01/17/2025 |
| From: | James Drake NRC/NRR/DORL/LPL4 |
| To: | Twarog J Entergy Operations |
| Drake, Jason | |
| References | |
| EPID: L-2024-LRO-0035 | |
| Download: ML25017A282 (1) | |
Text
From:
Jason Drake To:
Twarog, John R Cc:
Mahan, Cecil; Couture III, Philip; Peak, Monica Renee; Tony Nakanishi
Subject:
RAIs for Review: Waterford 3 - Review of Steam Generator Tube Inspection Report for the 25th RF (EPID: L-2024-LRO-0035)
Date:
Friday, January 17, 2025 12:10:00 PM Attachments:
FINAL RAIs_L-2024-LRO-0035_Waterford3 SGT IR for 25th RFI.pdf By letter dated July 22, 2024 (ML24204A270), Entergy Operations, Inc. (the licensee),
submitted information summarizing the results of the fall 2023 steam generator (SG) inspections performed at Waterford Steam Electric Station, Unit 3 (Waterford 3), during the 25 th refueling outage (RFO 25).
To complete its review, the NRC staff has a request for additional information (RAI) found in the attached document. Please provide your response to the subject RAIs within 30 days from the receipt of this email.
- Regards,
Jason Drake Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Phone: (301) 415-8378
REQUEST FOR ADDITIONAL INFORMATION REVIEW OF STEAM GENERATOR TUBE INSPECTION REPORT FOR THE 25TH RF INSPECTION WATERFORD STEAM ELECTRIC STATION, UNIT 3 ENTERGY OPERATIONS, INC.
DOCKET NO. 50-382 1.0 Background By letter dated July 22, 2024 (ML24204A270), Entergy Operations, Inc. (the licensee),
submitted information summarizing the results of the fall 2023 steam generator (SG) inspections performed at Waterford Steam Electric Station, Unit 3 (Waterford 3), during the 25 th refueling outage (RFO 25).
To complete its review of the inspection report, the NRC staff requests the following additional information:
2.0 Regulatory Basis Waterford 3 (WF3) Technical Specification (TS) 6.9.1.5, Steam Generator Tube Inspection Reports, requires Entergy Operations to submit a Tube Inspection Report to the NRC within 180 days after entry into MODE 4 following a steam generator inspection performed in accordance with TS 6.5.9, Steam Generator (SG) Program.
3.0 Questions RAI-01: Based on review of the detection and sizing technique information provided in the RFO 25 and RFO 21 report (ML17325B762), it is the NRC staffs understanding that Waterford does not have a plant-representative broached tube support plate (TSP) wear calibration standard.
- 1. Please confirm whether the NRC staffs understanding is correct.
- 2. If the staffs understanding is correct, and the calibration standard wear scars used in RFO 21 and RFO25 are at a different orientation or width compared to a TSP land, please discuss whether the difference(s) could result in bobbin coil under sizing of TSP wear depths. For example, could a wear flaw on a calibration standard of a given depth produce a larger amplitude signal compared to the same depth wear from a narrower TSP land?
- 3. If a plant representative broached TSP wear calibration standard has not been used for past inspections, please discuss if use of that type of standard is being considered for future steam generator tube inspections.
RAI-02: In the operational assessments performed in section 3.5 of the RFO 25 report, ten Monte Carlo simulations were performed with 100,000 trials each and the results of the ten simulations were averaged to calculate the probability of survival (POS).
- 1. Please discuss the range of POS results of the ten simulations.
- 2. Please discuss how the results of this calculation method might differ from performing one Monte Carlo simulation with 1,000,000 trials.
OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/BC NRR/DNRL/NVIB/BC NAME JDrake TNakanishi SBloom DATE 12/5/2024 12/10/2024 11/24/2024