ML21272A200

NRR E-mail Capture - Comanche Peak Unit 2 - Upcoming Steam Generator Tube Inservice Inspection (L-2021-NFO-0013)

ML21272A200
Person / Time
Site:	Comanche Peak
Issue date:	09/29/2021
From:	Dennis Galvin NRC/NRR/DORL/LPL4
To:	Struble G TEX Operations Company
References
L-2021-NFO-0013
Download: ML21272A200 (4)

Text

From: Galvin, Dennis Sent: Wednesday, September 29, 2021 12:24 PM To: Struble, Garry

Subject:

Comanche Peak Unit 2 - Upcoming Steam Generator Tube Inservice Inspection (L-2021-NFO-0013)

Attachments: Comanche Peak 2 SG Phone Call Discussion Points 2021-09-29.pdf

Dear Mr. Struble:

Inservice inspections of steam generator (SG) tubes play a vital role in assuring SG tube integrity. A telephone conference call has been arranged with members of your staff to discuss the ongoing results of the SG tube inspections to be conducted during the upcoming Comanche Peak Nuclear Power Plant, Unit No. 2 refueling outage. This call will occur after the majority of the tubes have been inspected, but before the SG inspection activities have been completed.

Enclosed is a list of discussion points to facilitate this call.

The U.S. Nuclear Regulatory Commission (NRC) staff will document a publicly available summary of the conference call, including any material that you provide to the NRC staff in support of the call.

Should you have any questions you can contact me at 301-415-6256.

Sincerely, Respectfully, Dennis Galvin, Project Manager Plant Licensing Branch 4 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-446

Enclosure:

Steam Generator Tube Inspection Discussion Points

Hearing Identifier: NRR_DRMA Email Number: 1366 Mail Envelope Properties (SA1PR09MB81113AC6D1B26DC809CA0F10FBA99)

Subject:

Comanche Peak Unit 2 - Upcoming Steam Generator Tube Inservice Inspection (L-2021-NFO-0013)

Sent Date: 9/29/2021 12:24:19 PM Received Date: 9/29/2021 12:24:00 PM From: Galvin, Dennis Created By: Dennis.Galvin@nrc.gov Recipients:

"Struble, Garry" <Garry.Struble@luminant.com>

Tracking Status: None Post Office: SA1PR09MB8111.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1090 9/29/2021 12:24:00 PM Comanche Peak 2 SG Phone Call Discussion Points 2021-09-29.pdf 84593 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

STEAM GENERATOR TUBE INSPECTION DISCUSSION POINTS The following discussion points have been prepared to facilitate the conference call arranged with the licensee to discuss the results of the steam generator tube inspections to be conducted during the upcoming Fall 2021, Comanche Peak Nuclear Power Plant, Unit No. 2 refueling outage. This conference call is scheduled to occur towards the end of the planned SG tube inspections, but before the unit completes the inspections and repairs.

The NRC staff plans to document a publicly available summary of the conference call, as well as any material that is provided in support of the call.

1. Discuss any trends in the amount of primary-to-secondary leakage observed during the recently completed cycle.

2. Discuss whether any secondary side pressure tests were performed during the outage and the associated results.

3. Discuss any exceptions taken to the industry guidelines.

4. For each steam generator, provide a description of the inspections performed including the areas examined and the probes used (e.g., dents/dings, sleeves, expansion-transition, U-bends with a rotating probe), the scope of the inspection (e.g., 100 percent of dents/dings greater than 5 volts and a 20 percent sample between 2 and 5 volts), and the expansion criteria.

5. For each area examined (e.g., tube supports, dent/dings, sleeves, etc), provide the following:

a. A summary of the number of indications identified to date for each degradation mode (e.g., number of circumferential primary water stress corrosion cracking indications at the expansion transition).

b. For the most significant indications in each area, provide an estimate of the severity of the indication (e.g., voltage, depth, and length of the indication), including whether tube integrity (structural and accident induced leakage integrity) was maintained during the previous operating cycle. In addition, discuss any analyses performed specifically for the most significant indications to demonstrate tube integrity.

c. Discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential primary water stress corrosion cracking at the expansion transition for the first time at this unit).

6. Describe repair/plugging plans.

7. Describe in-situ pressure test and tube pull plans and results (as applicable and if available).

8. Discuss the following regarding loose parts:

a. The inspections performed to detect loose parts.

b. A description of any loose parts detected and their location within the SG (including the source or nature of the loose part, if known).

c. If the loose parts were removed from the SG.

d. Indications of tube damage associated with the loose parts.

9. Discuss the scope and results of any secondary side inspection and maintenance activities (e.g., in-bundle visual inspections, feedring inspections, sludge lancing, assessing deposit loading, etc).

10. Discuss any unexpected or unusual results.

11. Provide the schedule for steam generator-related activities during the remainder of the current outage.