ML23033A032

NRR E-mail Capture - Request for Additional Information for Davis-Besse's 2022 Steam Generator Inspection Report (L-2022-LRO-0115)

ML23033A032
Person / Time
Site:	Davis Besse
Issue date:	02/01/2023
From:	Joel Wiebe NRC/NRR/DORL/LPL3
To:	Nicely K Energy Harbor Nuclear Corp
References
L-2022-LRO-0115
Download: ML23033A032 (4)

Text

From: Luke Haeg Sent: Wednesday, February 1, 2023 2:58 PM To: Nesser, Kathryn M Cc: Andy Johnson; Paul Klein; Greg Makar; Leslie Terry; Steven Bloom; Nancy Salgado

Subject:

Request for Additional Information for Davis-Besse's 2022 Steam Generator Inspection Report (L-2022-LRO-0115)

Attachments: Final RAI L-2022-LRO-0115.docx

Dear Ms. Nesser:

By letter dated September 29, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22272A497), Energy Harbor Nuclear Corp. (Energy Harbor, the licensee), submitted a report of steam generator tube inspections performed in accordance with Technical Specification (TS) 5.6.6, Steam Generator Tube Inspection Report, pursuant to TS 5.5.8, Steam Generator (SG) Program for the Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse).

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and determined that additional information is required to complete the review.

A request for additional information (RAI) is attached. The draft RAI was sent to you ensure that it was understandable, the regulatory basis for the question was clear, and to determine whether the information was previously docketed.

Based on a discussion with you, a response to the attached RAI is requested within 30 days from the date of this email.

The NRC staff considers that timely responses to RAIs help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. 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/LPL2-2 U.S. Nuclear Regulatory Commission 301-415-0272

Hearing Identifier: NRR_DRMA Email Number: 1930 Mail Envelope Properties (DM8PR09MB64071C1C82EB2D4F7BC5419098D19)

Subject:

Request for Additional Information for Davis-Besse's 2022 Steam Generator Inspection Report (L-2022-LRO-0115)

Sent Date: 2/1/2023 2:57:30 PM Received Date: 2/1/2023 2:57:00 PM From: Luke Haeg Created By: Lucas.Haeg@nrc.gov Recipients:

"Andy Johnson" <Andrew.Johnson@nrc.gov>

Tracking Status: None "Paul Klein" <Paul.Klein@nrc.gov>

Tracking Status: None "Greg Makar" <Gregory.Makar@nrc.gov>

Tracking Status: None "Leslie Terry" <Leslie.Terry@nrc.gov>

Tracking Status: None "Steven Bloom" <Steven.Bloom@nrc.gov>

Tracking Status: None "Nancy Salgado" <Nancy.Salgado@nrc.gov>

Tracking Status: None "Nesser, Kathryn M" <kmnesser@energyharbor.com>

Tracking Status: None Post Office: DM8PR09MB6407.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1527 2/1/2023 2:57:00 PM Final RAI L-2022-LRO-0115.docx 27136 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

REQUEST FOR ADDITIONAL INFORMATION REGARDING TECHNICAL SPECIFICATION 5.6.6 STEAM GENERATOR TUBE INSPECTION 180-DAY REPORT ENERGY HARBOR NUCLEAR CORP.

DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-346 EPID L-2022-LRO-0115 INTRODUCTION By letter dated September 29, 2022, (Agency wide Document Access Management System (ADAMS) Accession No. ML22272A497), Energy Harbor Nuclear Corp. (Energy Harbor, the licensee), submitted a report of steam generator tube inspections performed in accordance with Technical Specification (TS) 5.6.6, Steam Generator Tube Inspection Report, pursuant to TS 5.5.8, Steam Generator (SG) Program, for the Davis-Besse Nuclear Power Station, Unit No. 1 (Davis-Besse).

The Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by the licensee. The staff finds that the following additional information is required to complete their review.

REGULATORY BASIS Davis-Besse TS 5.6.6 requires, in part, that a report shall be submitted within 180 days after the initial entry into MODE 4 following completion of an inspection performed in accordance with TS 5.5.8, which requires, in part, that a SG Program shall be established and implemented to ensure that SG tube integrity is maintained.

INFORMATION REQUESTED

1. Please clarify the number of tubes plugged to date and causes of tube plugging in each SG following refueling outage 22 (1R22). As shown in the table below, the sum of tubes plugged following 1R21 (ML20260H057), and tubes reported plugged during 1R22, did not equal the total number of tubes reported plugged following 1R22.

Tube plugging description SG 2A SG 1B Total 1 Tubes plugged to date following 1R21 105 69 174 (Section 6 of ML20260H057) 2 Tubes plugged during 1R22 14 1 15 (Section 5 of ML22272A497) 3 Tubes plugged to date following 1R22 119 70 189 (based on sum of Row 1 and Row 2, above) 4 Tubes plugged to date following 1R22 135 82 217 (Section 6 of ML22272A497) 5 Discrepancy in the number of tubes plugged to 16 12 28 date following 1R22 (Row 4 minus Row 3)

2. For wear at drilled TSPs listed in the table in Section 4 of the report (page 86 of 89), the values of circumferential extent and percent degraded area (PDA) decreased compared to the 1R21 inspection report in almost all cases for the five indications included in both reports. This was in despite of the axial extent values increasing in all cases and the maximum depth values increasing or decreasing only slightly. Please explain the reason for the change, if known, such as a change in the flaw sizing methodology or PDA calculation. If there was a change, please describe the change and how it was benchmarked.

3. Please provide the results of the channel head and installed plug inspections for each SG in 1R22.

4. Please provide the scope and results of any secondary side inspection and maintenance activities performed, if any, in each SG during 1R22.