ML062180076
| ML062180076 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 08/11/2006 |
| From: | Pickett D NRC/NRR/ADRO/DORL/LPLII-2 |
| To: | Singer K Tennessee Valley Authority |
| Pickett D, NRR/DORL, 415-1364 | |
| References | |
| TAC MD2052, TAC MD2053, TS-06-02 | |
| Download: ML062180076 (4) | |
Text
August 11, 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, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING CONTAINMENT SUMP DESIGN CHANGES (TAC NOS. MD2052 AND MD2053)
Dear Mr. Singer:
By letter dated May 25, 2006, Tennessee Valley Authority (the licensee) requested an amendment to the operating license for the Sequoyah Nuclear Plant, Units 1 and 2, to modify the design and licensing basis for the containment sump debris transport analysis as described in the Sequoyah Updated Final Safety Analysis Report (TS-06-02).
In order for the staff to complete its review of this application, 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 by August 31, 2006.
Sincerely,
/RA/
Douglas V. Pickett, Senior Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328
Enclosure:
Request for Additional Information cc w/encl: See next page
ML062180076 NRR-088 OFFICE LPL2-2/PM LPL2-2/LA DSS/SSIB/BC LPL2-2/BC NAME DPickett RSola RArchitzel for MScott LRaghavan DATE 8/8/06 8/8/06 8/9/06 8/11/06
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
REQUEST FOR ADDITIONAL INFORMATION SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 UPDATED FINAL SAFETY ANALYSIS REPORT CHANGES ASSOCIATED WITH NRC GENERIC LETTER 2004-02 TAC NOS. MD2052 AND MD2053 By letter dated May 25, 2006, the licensee of the Sequoyah Nuclear Plant (SQN) proposed a change to their Operating License. The proposed change modifies the SQN design and licensing basis for the containment sump debris transport analysis. Their current transport analysis is a two-dimensional physical transport model and Tennessee Valley Authority (TVA) is requesting to update the analysis to a three-dimensional transport model using FLOW-3D computational fluid dynamics (CFD) computer code.
In order for the staff to evaluate the proposed change, the staff requests the following information:
(a)
Please specify the difference in the results of the current two-dimensional model and the proposed CFD transport analysis.
(b)
Watts Bar and Sequoyah are similar plants. The staff is currently performing an audit of the Watts Bar sump modifications and has gained a broad understanding of the proposed changes. To what extent do the two units have the same transport analysis?
Please provide the inputs, boundary conditions, and geometry that were different from Watts Bars transport analysis (if any).
(c)
SQN stated in the license amendment request (LAR) that the quantity of debris washed down by ice melt and spray was conservatively determined. Please provide more details of how the amount of debris was determined.
(d)
Please provide the basis for SQN to conclude that the appropriate ice melt and containment spray flow rates, and kinetic energy were used in the CFD calculation.
(e)
Please provide the basis for SQN to conclude that the appropriate turbulence model was selected for the CFD calculations.
(f)
Statement number 11 in the Debris Transport Methodology section of the LAR, states that the quantity of debris that could experience erosion due to the break flow, spray flow, or ice melt drainage was determined. Please provide more details of the fraction of erosion and types of debris.
Enclosure