ML22220A194

NRR E-mail Capture - Comanche Peak Unit 2 - Draft Request for Additional Information - 2RE19 Inspection Summary Report for Steam Generator Tubing

ML22220A194
Person / Time
Site:	Comanche Peak
Issue date:	08/08/2022
From:	Dennis Galvin NRC/NRR/DORL/LPL4
To:	Hicks J TEX Operations Company
References
L 2022-LRO-0065
Download: ML22220A194 (4)

Text

From: Galvin, Dennis Sent: Monday, August 8, 2022 10:45 AM To: Jack Hicks (Jack.Hicks@luminant.com)

Cc: Barnette, James

Subject:

Comanche Peak Unit 2 - Request for Additional Information - 2RE19 Inspection Summary Report for Steam Generator Tubing (EPID: L 2022-LRO-0065)

Attachments: Comanche Peak U2 Fall 2021 SGTIR Draft RAI 2022-08-08.pdf

Dear Mr. Hicks,

By letter dated May 5, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22125A267), Vistra Operations Company LLC submitted information summarizing the results of the 2021 steam generator (SG) inspections performed at Comanche Peak Nuclear Power Plant Unit 2. The inspections were performed during refueling outage 19 (2RF19).

To complete its review, the NRC staff has prepared a request for additional information (RAI) in DRAFT form.

To arrange a clarification call for the draft RAIs and to discuss the due date for the RAI response, please contact me at (301) 415-6256.

Respectfully, Dennis Galvin Project Manager U.S Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing Licensing Project Branch 4 301-415-6256 Docket No. 50-446

Hearing Identifier: NRR_DRMA Email Number: 1745 Mail Envelope Properties (SA1PR09MB81112A52DBFA7BF177FCFBEEFB639)

Subject:

Comanche Peak Unit 2 - Request for Additional Information - 2RE19 Inspection Summary Report for Steam Generator Tubing (EPID: L 2022-LRO-0065)

Sent Date: 8/8/2022 10:44:42 AM Received Date: 8/8/2022 10:44:00 AM From: Galvin, Dennis Created By: Dennis.Galvin@nrc.gov Recipients:

"Barnette, James" <James.Barnette@luminant.com>

Tracking Status: None "Jack Hicks (Jack.Hicks@luminant.com)" <Jack.Hicks@luminant.com>

Tracking Status: None Post Office: SA1PR09MB8111.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 873 8/8/2022 10:44:00 AM Comanche Peak U2 Fall 2021 SGTIR Draft RAI 2022-08-08.pdf 52545 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

DRAFT REQUEST FOR ADDITIONAL INFORMATION FALL 2021 STEAM GENERATOR TUBE INSPECTION REPORT VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNIT 2 DOCKET NO. 50-446 By letter dated May 5, 2022 (Agencywide Documents Access and Management Systems Accession No. ML22125A267), Vistra Operations Company LLC (the licensee) submitted information summarizing the results of the fall 2021 steam generator (SG) inspections performed at Comanche Peak Nuclear Power Plant (Comanche Peak), Unit 2. The inspections were performed during refueling outage 19 (2RF19).

All pressurized water reactors have Technical Specifications (TS) according to Section 50.36 of Title 10 of the Code of Federal Regulations that include an SG Program with specific criteria for the structural and leakage integrity, repair, and inspection of SG tubes. Comanche Peak Unit 2 TS 5.6.9 requires that a report be submitted within 180 days after the initial entry into hot shutdown following SG inspections performed in accordance with TS 5.5.9, which requires that an SG Program be established and implemented to ensure SG tube integrity is maintained.

To complete its evaluation of the inspection report, the U.S. Nuclear Regulatory Commission (NRC) staff requests the following information:

1. The table in Section c.4 shows that the tubes at Row 40 Column 48 (33 percent through wall), and Row 40 Column 49 (18 percent through wall), in SG 3, were stabilized and plugged. The information in Sections c.2 and c.3 indicates both tubes had single volumetric indications caused by foreign object wear.

With respect to foreign object wear projections, Section d, near the top of page 15 states, A total of 16 objects remained in secondary side of the SGs following 2RF19. All of these objects were small parts and demonstrated by bounding calculations through tube wear projections to not adversely affect tube integrity until at least 2RF22. However, Section c.3, near the top of page 12, states, no foreign objects remain within the vicinity of the affected tubes, so no OA [operational assessment] projection is provided.

These two statements about foreign object wear projections appear to be inconsistent.

Therefore, please clarify the basis for stabilizing and plugging these tubes, the location of foreign objects with respect to these tubes, and whether these objects were included in the operational assessment.

2. With respect to the single volumetric indication in the tube at Row 6 Column 79 in SG 3:

• In Section c.4, the table of tubes plugged or repaired, please clarify the use of the word Preventative as the Plugging Basis. According to Sections c.2 and c.3, the indication was 43 percent through wall, which would require plugging according to TS 5.5.9.c.

2

• Please clarify how this indication was assessed and determined to be foreign object wear (Section c.3) considering its location in the U-bend region (13.55 inches above tube support plate C11) and the absence of a corresponding foreign object in the summary table in Section f.

3. Please explain the meaning of Limiting/Total wear indications, shown with a value of 279 in the table of Wear Indication at Support Structures in Section c.2.