ML16242A012

NRR E-mail Capture - (External_Sender) PG&E Letter Dated May 2, 2016 - 180 Day Steam Generator Report for Diablo Canyon Power Plant, Unit 1, Refueling Outage 1R19 - CAC No. MF7649

ML16242A012
Person / Time
Site:	Diablo Canyon
Issue date:	08/25/2016
From:	Richardson M Pacific Gas & Electric Co
To:	Balwant Singal Plant Licensing Branch IV
References
MF7649
Download: ML16242A012 (3)

Text

NRR-PMDAPEm Resource From: Richardson, Michael <MJRm@pge.com>

Sent: Thursday, August 25, 2016 2:59 PM To: Singal, Balwant Cc: Johnson, Andrew; Bailey, Janis; Skov, Jeffrey

Subject:

[External_Sender] RE: PG&E Letter dated May 2, 2016 - 180 Day Steam Generator Report for Diablo Canyon Power Plant, Unit 1, Refueling Outage 1R19 - CAC No.

MF7649 Balwant, I received the following input from engineering regarding the clarification on the 180 day report.

The tube count difference you discussed reflects the difference in the number of tubes (16) indicating antivibration bar (AVB) wear as detected using the bobbin probe (termed a bobbin call) and the number of tubes (15) for which the AVB bobbin call was confirmed using the +Point probe. That is, there were a total of 16 tubes with AVB bobbin calls, 8 of which were in steam generator (SG) 12. Each AVB bobbin call was inspected using the +Point probe and one tube, 69-21 in SG 12, was found to be NDF (no degradation found) with +Point.

So the bobbin call remained, but the tube was not counted among the tubes with AVB wear.

This explains the 16 tubes reported on pp. 5 (top of page) and 6 (second full paragraph). The 16 tube count is based on AVB bobbin calls. The tube count numbers in Table 4 are correct based on +Point (15 affected tubes).

Table 4 does not include a 5% bobbin call at AV4 in SG 12 tube 69-21 which was NDF with +Point.

Please let me know if you have any additional questions or concerns.

Michael Richardson Supervisor, Regulatory Services Pacific Gas & Electric Company Diablo Canyon Power Plant Office: 805.545.4557l Cell: 805-440-3447l email: mjrm@pge.com From: Singal, Balwant [1]

Sent: Monday, August 22, 2016 4:47 AM To: Richardson, Michael Cc: Johnson, Andrew

Subject:

PG&E Letter dated May 2, 2016 - 180 Day Steam Generator Report for Diablo Canyon Power Plant, Unit 1, Refueling Outage 1R19 - CAC No. MF7649 This is an EXTERNAL EMAIL. Stop and think before clicking links or opening attachments.

By letter dated May 2, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16123A333), Pacific gas and Electric Company submitted 180 Day Steam Generator (SG) Report for Diablo Canyon Power Plant, Unit 1, Refueling Outage 1R19. The U.S. Nuclear Regulatory Commission (NRC) staff has the following clarifying question:

At various places in the May 2, 2016 letter, references are made to 15 and 16 tubes being found with wear that resulted from interaction with anti-vibration bars (AVBs) (e.g., pages 5 and 6 of the letter).

The SG inspections performed in 1R16 found an AVB wear indication in the tube in row 95 column 57 in SG 1-3. This tube is also included in Table 4 of the report from 1R19, yet Table 4 only lists 15 tubes.

Please clarify the number of tubes found with AVB wear in 1R19.

1

Please advise if a conference is needed to discuss this question with the NRC staff. An e-mail response providing the clarifying information will be acceptable for now. We will advise you if the response needed to be submitted on docket.

Your response by August 25, 2016 will be highly appreciated.

Thanks.

Balwant K. Singal Senior Project Manager (Diablo Canyon)

Nuclear Regulatory Commission Division of Operating Reactor Licensing Balwant.Singal@nrc.gov Tel: (301) 415-3016 Fax: (301) 415-1222 2

Hearing Identifier: NRR_PMDA Email Number: 3017 Mail Envelope Properties (926C8F6F197B0D4F99BF6E3D342F5CA79F748AC8)

Subject:

[External_Sender] RE: PG&E Letter dated May 2, 2016 - 180 Day Steam Generator Report for Diablo Canyon Power Plant, Unit 1, Refueling Outage 1R19 - CAC No. MF7649 Sent Date: 8/25/2016 2:59:04 PM Received Date: 8/25/2016 2:59:14 PM From: Richardson, Michael Created By: MJRm@pge.com Recipients:

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

Tracking Status: None "Bailey, Janis" <JxDj@pge.com>

Tracking Status: None "Skov, Jeffrey" <JMSP@pge.com>

Tracking Status: None "Singal, Balwant" <Balwant.Singal@nrc.gov>

Tracking Status: None Post Office: EXCHMBSF324.Utility.pge.com Files Size Date & Time MESSAGE 3164 8/25/2016 2:59:14 PM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received: