ML13014A094

NRR E-mail Capture - Fw: DC Cook U2 - Review of 2012 SG Tube Inspection Report

ML13014A094
Person / Time
Site:	Cook
Issue date:	01/10/2013
From:	Burgoyne D Indiana Michigan Power Co
To:	Thomas Wengert Division of Operating Reactor Licensing
References
TAC ME9720
Download: ML13014A094 (3)

Text

NRR-PMDAPEm Resource From: dmburgoyne@aep.com Sent: Thursday, January 10, 2013 2:18 PM To: Wengert, Thomas Cc: hletheridge@aep.com

Subject:

Fw: DC Cook U2 - Review of 2012 SG Tube Inspection Report (TAC No. ME9720)

Good afternoon, In December you sent questions to us regarding the U2 SG Tube Inspection Report. Due to the holidays and vacations, we were unable to schedule a conference call; however, the lead for the technical organization drafted the following responses to the questions. If you would still like to have a conference call, please let me know and we will get that arranged.

1. In the SG tube inspection report the licensee stated that secondary side inspections were performed in all four SGs, and then described the scope of inspections. When discussing the scope of inspection, you specifically discussed SG23. Please clarify which inspections were performed in each SG and which were limited to just SG 23.

Response

Visual inspection of the divider lane and annulus region at the top of the tubesheet was performed in all four steam generators. Select inner bundle passes i.e. inserting a remote video probe into the tube bundle at the top of the tubesheet was also performed in all four SGs, primarily to examine the sludge pile region. The reference to SG 23 was intended to denote that this was the only steam generator in which FOSAR (foreign object search and retrieval) efforts were performed. The need for FOSAR resulted from two new possible loose part signals that were detected during the eddy current inspection, both in SG 23. As a result, FOSAR was performed to examine these specific locations. A sludge rock was found in one location and nothing was found at the second location. The sludge rock could not be removed and was dispositioned to be left in service. Bounding eddy current examinations were performed in these regions and no additional possible loose part signals were identified. No tube wear was detected at the location of the possible loose part signals nor in any of the bounding tubes examined.

2. In a response to a request for additional information dated August 5, 2008 on the 2007 SG tube inservice inspections (ADAMS Accession No. ML082390706), you reported that an area of minor surface pitting was found on the underside of the primary separator diffuser window (also known as the primary separator intermediate plate assembly) on SG 22. However, in your October 2, 2012, letter you indicated that steam drum inspections performed in two SGs during the previous inspection identified no degradation or abnormal conditions. Please clarify.

Response

The minor pitting was reported on SG 22 during the previous inspection as described above. Phrasing in our October 2, 2012 letter should have denoted this condition and clarified that no significant degradation had previously been noted during steam drum inspections. Due to the inconsequential nature of the pitting, it was not considered a degradation mechanism of concern nor an abnormal condition on a steam generator that has been in service since 1989.

Thank you, Danielle Burgoyne Licensing Activity Coordinator Donald C. Cook Nuclear Plant Phone: 269.466.2871 1

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Forwarded by Helen L Etheridge/BC1/AEPIN on 12/19/2012 08:25 AM -----

"Wengert, Thomas" <Thomas.Wengert@nrc.gov> To "hletheridge@aep.com" <hletheridge@aep.com>

cc "mkscarpello@aep.com" <mkscarpello@aep.com>, "jrwaters@aep.com" 12/18/2012 11:29 AM <jrwaters@aep.com>

Subject DC Cook U2 - Review of 2012 SG Tube Inspection Report (TAC No. ME9720)

Helen, The staff in the NRCs Division of Engineering are reviewing your October 2, 2012, submittal concerning the 2012 Steam Generator Tube Inspection Report for DC Cook Unit 2 (ADAMS Accession No. ML12284A278) and would like clarification of the submittal as follows:

1. In the SG tube inspection report the licensee stated that secondary side inspections were performed in all four SGs, and then described the scope of inspections. When discussing the scope of inspection, you specifically discussed SG23. Please clarify which inspections were performed in each SG and which were limited to just SG 23.

2. In a response to a request for additional information dated August 5, 2008 on the 2007 SG tube inservice inspections (ADAMS Accession No. ML082390706), you reported that an area of minor surface pitting was found on the underside of the primary separator diffuser window (also known as the primary separator intermediate plate assembly) on SG 22. However, in your October 2, 2012, letter you indicated that steam drum inspections performed in two SGs during the previous inspection identified no degradation or abnormal conditions. Please clarify.

DC Cook can provide a response to these clarification questions either by e-mail or a phone call, whichever you prefer.

The NRC staff will document the response in our steam generator report review.

Please contact me if you have questions or if you would like to have a conference call with the NRC staff to clarify.

Regards, Tom Wengert Project Manager - DC Cook and Prairie Island USNRC NRR/DORL/LPL3-1 (301) 415-4037 This e-mail message and all attachments transmitted with it from the Nuclear Generation Group of American Electric Power are for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.

2

Hearing Identifier: NRR_PMDA Email Number: 575 Mail Envelope Properties (OFCF168FF0.3AD2A631-ON85257AEF.006979B5-85257AEF.006A075E)

Subject:

Fw: DC Cook U2 - Review of 2012 SG Tube Inspection Report (TAC No.

ME9720)

Sent Date: 1/10/2013 2:18:09 PM Received Date: 1/10/2013 2:19:06 PM From: dmburgoyne@aep.com Created By: dmburgoyne@aep.com Recipients:

"hletheridge@aep.com" <hletheridge@aep.com>

Tracking Status: None "Wengert, Thomas" <Thomas.Wengert@nrc.gov>

Tracking Status: None Post Office: aep.com Files Size Date & Time MESSAGE 5622 1/10/2013 2:19:06 PM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

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