HNP-11-089, Response to Request for Clarification Regarding 180-day Steam Generator Tube Inspection Report

Response to Request for Clarification Regarding 180-day Steam Generator Tube Inspection Report

ML11271A057
Person / Time
Site:	Harris
Issue date:	09/22/2011
From:	Corlett D Progress Energy Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
HNP-11-089
Download: ML11271A057 (5)

Text

Progress Energy 10 CFR 50.4 September 22, 2011 Serial: HNP-11-089 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 Shearon Harris Nuclear Power Plant / Unit I Docket No. 50-400 / Renewed License No. NPF-63

Subject:

Response to Request for Clarification regarding 180-day Steam Generator Tube Inspection Report

References:

1. Letter from D. Corlett to the Nuclear Regulatory Commission, Serial HNP-1 1-045, "Shearon Harris Nuclear Power Plant, Unit 1, Docket No. 50-400 / Renewed License No. NPF-63, 180-day Steam Generator Tube Inspection Report" dated May 5, 2011.

2. Email from B. Mozafari, USNRC, to J. Caves "Shearon Harris Unit I SG Inspection Report (TAC No. ME635 8)" dated August 23, 2011.

Ladies and Gentlemen:

By letter dated May 5, 2011, identified as Reference I above, Carolina Power & Light Company, doing business as Progress Energy Carolinas, Inc., submitted the 180-Day Steam Generator Tube Inspection Report for the Shearon Harris Nuclear Power Plant (HNP).

On August 23, 2011, HNP received a request for clarification of three points in the report, transmitted as Reference 2. HNP's response to the request for clarification is attached as an enclosure to this letter.

This document contains no new regulatory commitments.

Progress Energy Carolinas, Inc.

Harris Nuclear Plant AOO P. 0. Box 165 New Hill, NC27562

U. S. Nuclear Regulatory Commission Page 2 HNP-1 1-089 If there are any questions or if additional information is needed, please contact me at 919.362.3137.

Dave Corlett Supervisor, Licensing/Regulatory Programs Harris Nuclear Plant

Enclosure:

Response to Request for Clarification regarding Shearon Harris Unit I Steam Generator Inspection Report cc: Mr. J. D. Austin, NRC Sr. Resident Inspector, HNP Mr. V. M. McCree, NRC Regional Administrator, Region II Mrs. B. L. Mozafari, NRC Project Manager, HNP

U. S. Nuclear Regulatory Commission Page 3 HNP-1 1-089 bcc:

Mr. D. T. Conley Mr. J. W. Donahue Mr. J. D. Dufner Mr. S. D. Ebneter Mr. D. G. Eisenhut Mr. D. Griffith Mr. R. K. Holbrook Mr. W. Jefferson Jr.

Mr. E. J. Kapopoulos Jr.

Mr. C. W. Kornegay Mr. B. C. McCabe Mr. H. J. Miller Mr. G. D. Miller Mr. G. Peterson Mr. J. Scarola Mr. M. S. Tuckman Mr. J. C. Warner HNP NOS NTA Licensing Files (2 copies)

Nuclear Records

U. S. Nuclear Regulatory Commission Page lof2 HNP-1 1-089 Enclosure Response to Request for Clarification regarding 180-day Steam Generator Tube Inspection Report Question 1: For each refueling outage and SG tube inspection outage since installationof the replacement SGs, provide the cumulative effective full power months that the SGs have operated.

Response 1:

Outage Number Year Cumulative Outage Type EFPM ROW1 Fall 2001 0.0 S/G Replacement ROl1 Spring 2003 15.4 S/G tube inspection/Refueling Mid Cycle 12 Spring 2004 26.6 Unplanned S/G tube inspection following leak R012 Fall 2004 31.4 Refueling R013 Spring 2006 47.9 S/G tube inspection/Refueling R014 Fall 2007 64.1 Refueling RO15 Spring 2009 81.5 Refueling R016 Fall 2010 98.0 S/G tube inspection/Refueling Question 2: During the 2006 SG inspections, a restrictionwas identified approximately 22 inchesfrom the cold-leg tube end in SG B. Discuss what inspections, if any, were performed on this tube in the fall 2010 refueling outage. In addition, discuss the results of these inspections.

Response 2: The restriction identified during the 2006 inspection was located at row 23, column 26.

During this inspection, the full size .560 Bobbin Probe (Zetec EC-560-LLMC) was unable to complete the full length exam. The probe was inserted from tube end hot and met the restriction at tube sheet cold.

A .520 RPC Zetec probe was then inserted from tube end cold and through the restriction at tube sheet cold. No degradation was detected. The restriction was believed to be caused by the .560 Bobbin Probe itself and not by a defect in the tube. In 2010, the tube was inspected with a similar .560 Bobbin Probe (Zetec LLMC-EC-.560-110-36). This probe completed a full length exam without restriction. No detectable degradation was discovered on this tube during the 2010 inspection.

U. S, Nuclear Regulatory Commission Page 2of 2 HNP- 11-089 Enclosure Question 3: Provide any observations on whether any new dents/dings were identified during the fall 2010 inspectionsand whether the dents identified duringthe 2006 inspections (at the 8th and 9th tube supportplates in SG C) have changed If either new dents were identified or the previous dents have changed in size, provide details regardingthe cause of the new/changing indications.

Response 3: There were 12 new dents in S/G A, 2 new dents in S/G B, and 0 new dents in S/G C identified during the fall 2010 inspections. There was a slight difference in the voltage of previous dents (including those at the 8th and 9th tube support plates in S/G C) where some went up and others went down. The differences can be attributed to a change in probe type and also the orientation of the probe by the dent. The change in voltage was not deemed significant.

Although the scope of the 2010 inspection was roughly 50% of the 2006 inspection, the number of new dents discovered during the 2010 inspection has shown a marked decrease.

New Dents New Dents 2010 2006 S/G A 12 222 S/G B 2 12 S/G C 0 174