ML14024A034

Request for Additional Information Regarding End of Cycle 15 Steam Generator Tube Inservice Inspection Report

ML14024A034
Person / Time
Site:	Millstone
Issue date:	01/30/2014
From:	James Kim Plant Licensing Branch 1
To:	Heacock D Dominion Nuclear Connecticut
Kim J
References
TAC MF2919
Download: ML14024A034 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 30, 2014 Mr. David A. Heacock President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.

lnnsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

MILLSTONE POWER STATION, UNIT 3- REQUEST FOR ADDITIONAL INFORMATION REGARDING END OF CYCLE 15 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT (TAC NO. MF2919)

Dear Mr. Heacock:

By letter dated October 2, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13284A065), Dominion Nuclear Connecticut, Inc. (the licensee),

submitted information summarizing the results of the 2013 steam generator tube inspections at Millstone Power Station, Unit 3. These inspections were performed during the fifteenth refueling outage.

The U.S. Nuclear Regulatory Commission staff has reviewed the information provided by the licensee and has determined that the enclosed request for additional information (RAI) is needed in order to complete the review. A response to this RAI is requested to be provided within 60 days of the date of this letter.

If you have any questions regarding this matter, please contact me at 301-415-4125.

Sincerely, James Kim, Project Manager Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423

Enclosure:

As stated cc w/encl: Distribution via Listserv

OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION STEAM GENERATOR TUBE INSERVICE INSPECTION MILLSTONE POWER STATION, UNIT 3 DOCKET NUMBER 50-423 By letter dated October 2, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13284A065), Dominion Nuclear Connecticut, Inc. (the licensee),

submitted information summarizing the results of the 2013 steam generator tube inspections at Millstone Power Station, Unit 3. These inspections were performed during the fifteenth refueling outage. In order to complete its review of the documents listed above, the staff needs the following additional information:

1. Page 2 of Enclosure 1 to your October 2 letter indicates that secondary side activities were performed in Steam Generators (SGs) B, C, and D, including high-pressure sludge lancing and upper bundle flushing; a post-sludge lancing visual examination of the top-of-the-tubesheet annulus and no-tube lane; a visual investigation of accessible locations having eddy current testing indications potentially related to foreign objects; and, if present, removal of retrievable foreign objects. Please discuss the results of these inspections.

2. Page 2 of Enclosure 1 to your October 2 letter indicates that secondary side upper internal examinations were performed in SG C. Please discuss the results of these examinations (e.g., was any degradation observed on any of the secondary side internals, were the tube support openings clear of deposits, etc.).

3. Please discuss the scope and results of any tube plug inspections (e.g., was there any degradation and were all plugs in their proper locations).

4. Please discuss the scope and results of any inspections performed in the SG primary channel heads.

5. A number of new wear indications were reported during refueling outage (RFO) 15 both at the anti-vibration bars and at the tube support plates. Please discuss any insights on the reason for the increase in the number of indications. In addition, some of the wear indications at the tube support plates appeared to initiate and grow significantly over the last operating interval. Please discuss any insights on the growth of these indications.

Please discuss whether the size of these indications was consistent with your projections in your last operational assessment. If not, please discuss any corrective action taken to address any under predictions.

6. Please clarify whether any high row tubes have potentially elevated residual stresses, as evidenced by the eddy current data (i.e., 2-sigma tubes). If there are such tubes, please Enclosure

discuss how many tubes there are and whether any rotating probe (or array) exams were performed on these tubes at locations such as the expansion transition, dents, or dings.

7. During RFO 14, several tubes were plugged since the bottom of the expansion transition was greater than 1-inch below the top of the tubesheet. Please confirm that the bottom of the expansion transition was less than 1-inch below the top of the tubesheet in all tubes in the SGs inspected during RFO 15.

January 30, 2014 Mr. David A. Heacock President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.

lnnsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

MILLSTONE POWER STATION, UNIT 3- REQUEST FOR ADDITIONAL INFORMATION REGARDING END OF CYCLE 15 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT (TAC NO. MF2919)

Dear Mr. Heacock:

By letter dated October 2, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13284A065), Dominion Nuclear Connecticut, Inc. (the licensee),

submitted information summarizing the results of the 2013 steam generator tube inspections at Millstone Power Station, Unit 3. These inspections were performed during the fifteenth refueling outage.

The U.S. Nuclear Regulatory Commission staff has reviewed the information provided by the licensee and has determined that the enclosed request for additional information (RAI) is needed in order to complete the review. A response to this RAI is requested to be provided within 60 days of the date of this letter.

If you have any questions regarding this matter, please contact me at 301-415-4125.

Sincerely, Ira/

James Kim, Project Manager Plant Licensing Branch 1-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423

Enclosure:

As stated cc w/encl: Distribution via Listserv Distribution:

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. memo dated J anuary 15, 2014 OFFICE LPL 1-1/PM LPL 1-1/LA DE/ESGB/BC LPL 1-1/BC NAME JKim KGoldstein GKulesa* BBeaslev DATE 1/28/14 1/28/14 1/15/14 1/30/14 OFFICIAL RECORD COPY