ML24261B928

NRR E-mail Capture - for Your Action Discussion Points - Steam Generator Tube Inspection Call with SNC Regarding Vogtle, Unit 3

ML24261B928
Person / Time
Site:	Vogtle
Issue date:	09/17/2024
From:	John Lamb Plant Licensing Branch II
To:	Blackburn C, Lowery K Southern Nuclear Operating Co
References
Download: ML24261B928 (3)

Text

From: John Lamb Sent: Tuesday, September 17, 2024 11:24 AM To: Lowery, Ken G.; Blackburn, Cotasha Wilson Cc: Joyce, Ryan M.; Steven Bloom; Greg Makar; Paul Klein; Andy Johnson; Leslie Terry

Subject:

For Your Action: Discussion Points - Steam Generator Tube Inspection Call with SNC regarding Vogtle, Unit 3

Cotasha and Ken,

Below are the discussion points for the Vogtle, Unit 3, Steam Generator Tube Inspection conference call.

Thanks.

John

STEAM GENERATOR TUBE INSPECTION DISCUSSION POINTS REGARDING VOGTLE, UNIT 3

The following discussion points have been prepared to facilitate the conference call arranged with Southern Nuclear Operating Company (SNC, the licensee) to discuss the results of the steam generator (SG) tube inspections to be conducted during the upcoming October 2024, Vogtle, Unit 3, refueling outage (RFO). 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 U.S. Nuclear Regulatory Commission (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.

The discussion points for the conference call are the following:

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 RFO and the associated results.

3. Discuss any exceptions taken to the industry guidelines.

4. For each SG, 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% of dents/dings greater than 5 volts and a 20% 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).

d. Recent operating experience in both the United States and internationally has indicated that very large SGs have increased susceptibility to aggressive wear from tube supports on tubes in the low rows. Describe the examinations and results of inspections performed in the low row tubes and how the results will be considered in the operational assessment.

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 RFO.

Hearing Identifier: NRR_DRMA Email Number: 2606

Mail Envelope Properties (MN2PR09MB5084CF72167D89AB9697F4DAFA612)

Subject:

For Your Action Discussion Points - Steam Generator Tube Inspection Call with SNC regarding Vogtle, Unit 3 Sent Date: 9/17/2024 11:24:13 AM Received Date: 9/17/2024 11:24:00 AM From: John Lamb

Created By: John.Lamb@nrc.gov

Recipients:

"Joyce, Ryan M." <RMJOYCE@southernco.com>

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

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

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

Tracking Status: None "Andy Johnson" <Andrew.Johnson@nrc.gov>

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

Tracking Status: None "Lowery, Ken G." <KGLOWERY@southernco.com>

Tracking Status: None "Blackburn, Cotasha Wilson" <CWILSON@southernco.com>

Tracking Status: None

Post Office: MN2PR09MB5084.namprd09.prod.outlook.com

Files Size Date & Time MESSAGE 3768 9/17/2024 11:24:00 AM

Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: