ML060040165

RAI, the Cycle 13 Steam Generator Tube Inservice Inspections

ML060040165
Person / Time
Site:	Sequoyah
Issue date:	01/13/2006
From:	Pickett D Plant Licensing Branch III-2
To:	Singer K Tennessee Valley Authority
References
TAC MC8712
Download: ML060040165 (4)

Text

January 13, 2006 Mr. Karl W. Singer Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNIT 1 REQUEST FOR ADDITIONAL INFORMATION REGARDING THE CYCLE 13 STEAM GENERATOR TUBE INSERVICE INSPECTIONS (TAC NO. MC8712)

Dear Mr. Singer:

By letter dated November 22, 2004, the Tennessee Valley Authority (TVA, the licensee) submitted the steam generator (SG) tube plugging report in accordance with Technical Specification (TS) Section 4.4.5.5.a. By letter dated February 15, 2005, TVA submitted the 90-day inservice inspection summary report in accordance with the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, Article IWA-6230. By letter dated October 20, 2005, TVA submitted the 12-month SG inspection report in accordance with TS Section 4.4.5.5.b. The Cycle 13 SG tube inservice inspections were the first SG tube inspections since SG replacement.

In order for the staff to complete its review of the reports, we request that the licensee provide responses to the enclosed request for additional information (RAI). Based on discussions with your staff, we understand that you intend to respond to this RAI within 60 days of receipt of this letter.

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. 50-327

Enclosure:

Request for Additional Information cc w/enclosure: See next page

ML060040165 NRR-088 OFFICE LPL2-2 LPL2-2/PM LPLD2-2/LA CSGB/BC LPLB2-2/BC NAME MVaaler DPickett RSola AHiser MMarshall by memo dated DATE 1/9/06 1/10/06 1/10/06 1/13/06 12 / 13 / 05 Mr. Karl W. Singer Tennessee Valley Authority SEQUOYAH NUCLEAR PLANT 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, General Manager Nuclear Engineering 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

REQUEST FOR ADDITIONAL INFORMATION SEQUOYAH NUCLEAR PLANT, UNIT 1 CYCLE 13 STEAM GENERATOR TUBE INSERVICE INSPECTIONS DOCKET NO. 50-327 Questions Regarding the 12-Month Steam Generator (SG) Tube Inservice Inspection Report

1. Your report indicated that 100-percent of the dents and dings greater than or equal to 2-volts between the top of the hot leg tubesheet and the top of the cold leg tubesheet were examined with a +Point' probe. Discuss the results of these +Point' probe inspections, including the number of dents/dings in each SG. In addition, discuss if there were any new dents/dings or any anomalous dent signals.

2. Please indicate if the 11 wear indications in the area of the 2nd and 4th vertical straps were inspected with bobbin and +Point' probes. If the wear indications were not inspected with a +Point' probe, please discuss how you concluded that the indications were wear. In addition, the staff noted that several of the wear indications were located in the same general vicinity. Please provide any insights on the pattern of the wear indications.

3. Your report provided information about flaws in specific tubes and at specific locations within a tube. In order for the U.S. Nuclear Regulatory Commission staff to better understand where your indications are being detected and for future reference, please provide the following information regarding the design of your replacement SGs: a tubesheet map, a tube support plate diagram, the heat transfer surface area, the tubesheet thickness (with and without the clad), the lattice grid thickness, the tube support plate thickness, and a description of the U-bend support system, including the thickness and the tubing supported by the various supports. In addition, discuss whether you have a flow distribution baffle to distribute flow at the top of the tubesheet, including the thickness.

ENCLOSURE