ML062840715
| 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 signed on LRaghavan DATE 10/18/06 10/18/06 10/19/06 09/28/06 10/19/06
Enclosure 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.
Mr. Karl W. Singer SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority cc:
Mr. Ashok S. Bhatnagar, Senior Vice President Nuclear Operations Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Larry S. Bryant, Vice President Nuclear Engineering & Technical Services Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Robert J. Beecken, Vice President Nuclear Support Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Randy Douet Site Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37384-2000 General Counsel Tennessee Valley Authority ET 11A 400 West Summit Hill Drive Knoxville, TN 37902 Mr. John C. Fornicola, Manager Nuclear Assurance and Licensing Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Glenn W. Morris, Manager Corporate Nuclear Licensing and Industry Affairs Tennessee Valley Authority 4X Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 Mr. Paul L. Pace, Manager Licensing and Industry Affairs ATTN: Mr. James D. Smith Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37384-2000 Mr. David A. Kulisek, Plant Manager Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37384-2000 Senior Resident Inspector Sequoyah Nuclear Plant U.S. Nuclear Regulatory Commission 2600 Igou Ferry Road Soddy Daisy, TN 37379 Mr. Lawrence E. Nanney, Director Division of Radiological Health Dept. of Environment & Conservation Third Floor, L and C Annex 401 Church Street Nashville, TN 37243-1532 County Mayor Hamilton County Courthouse Chattanooga, TN 37402-2801 Ms. Ann P. Harris 341 Swing Loop Road Rockwood, Tennessee 37854