ML062840715

RAI, 2005 SG Tube Inspections

ML062840715
Person / Time
Site:	Sequoyah
Issue date:	10/19/2006
From:	Pickett D NRC/NRR/ADRO/DORL/LPLII-2
To:	Singer K Tennessee Valley Authority
Pickett D, NRR/DORL, 415-1364
References
TAC MD0508
Download: ML062840715 (4)

Text

October 19, 2006 Mr. Karl W. Singer Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNIT 2 REQUEST FOR ADDITIONAL INFORMATION REGARDING THE 2005 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. MD0508)

Dear Mr. Singer:

By letters dated May 31, 2005 (ML051600187 [Agencywide Documents Access and Management System Accession Number]), August 10, 2005 (ML052350675), August 15, 2005 (ML052340503), February 22, 2006 (ML060540467), and March 2, 2006 (ML060740605),

Tennessee Valley Authority (TVA, the licensee) submitted information concerning the 2005 steam generator (SG) tube inspections at Sequoyah Nuclear Plant, Unit 2. In addition to these reports, the Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2005 SG tube inspection in a letter dated July 8, 2005 (ML051810694).

In a letter dated May 1, 2006 (ML060960158), the NRC staff documented its review of the May 31, 2005, August 15, 2005, and February 22, 2006 letters pertaining to implementation of the voltage-based and W* alternate repair criteria.

In order for the staff to complete its review of the information provided by the licensee, we request that TVA provide responses to the enclosed request for additional information (RAI).

Based on discussions with your staff, we understand that you plan to respond to the enclosed RAI within 60 days of receipt of this letter. If you have any questions about this material, please contact me at (301) 415-1364.

Sincerely,

/RA/

Douglas V. Pickett, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No: 50-328

Enclosure:

As stated cc w/enclosure: See next page

ML062840715 NRR-088 OFFICE LPL2-2 LPL2-2/PM LPL2-2/LA CSGB/BC LPL2-2/BC NAME JPaige DPickett RSola AHiser as LRaghavan signed on DATE 10/18/06 10/18/06 10/19/06 09/28/06 10/19/06 REQUEST FOR ADDITIONAL INFORMATION SEQUOYAH NUCLEAR PLANT, UNIT 2 2005 STEAM GENERATOR TUBE INSPECTIONS DOCKET NO. 50-328

1. Please discuss the scope and results of your foreign object search and retrieval. If any loose parts were left in the steam generator, please discuss whether any analyses were performed to confirm that tube integrity would not be compromised for the time interval between inspections. In addition, if the locations corresponding to any potential loose part indications (detected via eddy current inspection) could not be visually inspected, please discuss your basis for dispositioning these tubes (if they were not plugged/stabilized).

2. It was indicated that +PointTM examinations were performed on new indications of cold-leg thinning to confirm that the indication is not crack-like. Please discuss how you confirm that historic indications have not developed crack-like indications (e.g., do you perform rotating probe examinations on a sample of these indications to confirm the absence of cracking). Similarly discuss how you ensure that other volumetric indications (such as wear at anti-vibration bars) do not contain (or have not developed) crack-like indications.

3. Several tubes with axially oriented outside diameter stress corrosion cracking were preventively plugged due to the potential for extreme voltage growth. Please provide the bobbin and rotating probe voltages for these indications.

4. One tube was preventively plugged since it was not fully expanded into the tubesheet.

Please discuss whether all tubes currently in service have nominally been expanded for the full depth of the hot-leg tubesheet.

Enclosure

Mr. Karl W. Singer SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority cc:

Mr. Ashok S. Bhatnagar, Senior Vice President Mr. Glenn W. Morris, Manager Nuclear Operations Corporate Nuclear Licensing Tennessee Valley Authority and Industry Affairs 6A Lookout Place Tennessee Valley Authority 1101 Market Street 4X Blue Ridge Chattanooga, TN 37402-2801 1101 Market Street Chattanooga, TN 37402-2801 Mr. Larry S. Bryant, Vice President Nuclear Engineering & Technical Services Mr. Paul L. Pace, Manager Tennessee Valley Authority Licensing and Industry Affairs 6A Lookout Place ATTN: Mr. James D. Smith 1101 Market Street Sequoyah Nuclear Plant Chattanooga, TN 37402-2801 Tennessee Valley Authority P.O. Box 2000 Mr. Robert J. Beecken, Vice President Soddy Daisy, TN 37384-2000 Nuclear Support Tennessee Valley Authority Mr. David A. Kulisek, Plant Manager 6A Lookout Place Sequoyah Nuclear Plant 1101 Market Street Tennessee Valley Authority Chattanooga, TN 37402-2801 P.O. Box 2000 Soddy Daisy, TN 37384-2000 Mr. Randy Douet Site Vice President Senior Resident Inspector Sequoyah Nuclear Plant Sequoyah Nuclear Plant Tennessee Valley Authority U.S. Nuclear Regulatory Commission P.O. Box 2000 2600 Igou Ferry Road Soddy Daisy, TN 37384-2000 Soddy Daisy, TN 37379 General Counsel Mr. Lawrence E. Nanney, Director Tennessee Valley Authority Division of Radiological Health ET 11A Dept. of Environment & Conservation 400 West Summit Hill Drive Third Floor, L and C Annex Knoxville, TN 37902 401 Church Street Nashville, TN 37243-1532 Mr. John C. Fornicola, Manager Nuclear Assurance and Licensing County Mayor Tennessee Valley Authority Hamilton County Courthouse 6A Lookout Place Chattanooga, TN 37402-2801 1101 Market Street Chattanooga, TN 37402-2801 Ms. Ann P. Harris 341 Swing Loop Road Rockwood, Tennessee 37854