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, 2006Mr. Karl W. SingerChief 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 ADDITIONALINFORMATION 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 the90-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 accordancewith TS Section 4.4.5.5.b. The Cycle 13 SG tube inservice inspections were the first SG tubeinspections since SG replacement. In order for the staff to complete its review of the reports, we request that the licensee provideresponses 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 ManagerPlant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No. 50-327

Enclosure:

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

ML060040165 NRR-088OFFICELPL2-2LPL2-2/PMLPLD2-2/LACSGB/BCLPLB2-2/BCNAMEMVaalerDPickettRSolaAHiserMMarshallDATE1/9/06 1/10/06 1/10/06 by memo dated 12 / 13 / 05 1/13/06 Mr. Karl W. SingerTennessee Valley Authority SEQUOYAH NUCLEAR PLANT 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, General ManagerNuclear Engineering Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801Mr. Robert J. Beecken, Vice PresidentNuclear Support Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Randy DouetSite Vice President Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37384-2000General CounselTennessee Valley Authority ET 11A 400 West Summit Hill DriveKnoxville, TN 37902Mr. John C. Fornicola, ManagerNuclear Assurance and Licensing Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801Mr. Glenn W. Morris, Manager Corporate Nuclear Licensing and Industry Affairs Tennessee Valley Authority 4X Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801Mr. Paul L. Pace, ManagerLicensing and Industry Affairs ATTN: Mr. James D. Smith Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37384-2000Mr. David A. Kulisek, Plant ManagerSequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37384-2000Senior Resident InspectorSequoyah Nuclear Plant U.S. Nuclear Regulatory Commission 2600 Igou Ferry Road Soddy Daisy, TN 37379Mr. Lawrence E. Nanney, DirectorDivision of Radiological Health Dept. of Environment & Conservation Third Floor, L and C Annex 401 Church Street Nashville, TN 37243-1532County MayorHamilton County Courthouse Chattanooga, TN 37402-2801Ms. Ann P. Harris341 Swing Loop Road Rockwood, Tennessee 37854 ENCLOSUREREQUEST FOR ADDITIONAL INFORMATIONSEQUOYAH NUCLEAR PLANT, UNIT 1CYCLE 13 STEAM GENERATOR TUBE INSERVICE INSPECTIONSDOCKET NO. 50-327Questions Regarding the 12-Month Steam Generator (SG) Tube Inservice Inspection Report1.Your report indicated that 100-percent of the dents and dings greater than or equal to2-volts between the top of the hot leg tubesheet and the top of the cold leg tubesheetwere examined with a +PointŽ probe. Discuss the results of these +PointŽ 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 2 nd and 4 th vertical strapswere inspected with bobbin and +PointŽ probes. If the wear indications were not inspected with a +PointŽ probe, please discuss how you concluded that the indicationswere 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 locationswithin 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, thetubesheet thickness (with and without the clad), the lattice grid thickness, the tubesupport plate thickness, and a description of the U-bend support system, including thethickness 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.