ML061730232
| ML061730232 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 06/30/2006 |
| From: | Pickett D NRC/NRR/ADRO/DORL/LPLD |
| To: | Singer K Tennessee Valley Authority |
| References | |
| TAC MC8248 | |
| Download: ML061730232 (4) | |
Text
June 30, 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:
WATTS BAR NUCLEAR PLANT, UNIT 1 REQUEST FOR ADDITIONAL INFORMATION RE: EMERGENCY CORE COOLING SYSTEM (ECCS)
EVALUATION MODEL CHANGES (TAC No. MC8248)
Dear Mr. Singer:
By Letter dated August 16, 2005, the Tennessee Valley Authority notified the Nuclear Regulatory Commission (NRC) of a change in the Watts Bar Nuclear Plant, Unit 1, ECCS evaluation models for peak cladding temperature (PCT) in accordance with Title 10 of the Code of Federal Regulations, Section 50.46 related to a temporary change of more than 50 degrees Fahrenheit in calculated PCT.
The NRC staff has identified the enclosed Request for Additional Information which will be necessary in order to complete our review. Based on discussions with your staff, we understand that you expect to respond to this request by approximately August 18, 2006.
Sincerely,
/RA/
Douglas V. Pickett, Senior Project Manager Plant Licencing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-390
Enclosure:
As stated cc w/enclosure: See next page
June 30, 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:
WATTS BAR NUCLEAR PLANT, UNIT 1 REQUEST FOR ADDITIONAL INFORMATION RE: EMERGENCY CORE COOLING SYSTEM (ECCS)
EVALUATION MODEL CHANGES (TAC No. MC8248)
Dear Mr. Singer:
By Letter dated August 16, 2005, the Tennessee Valley Authority notified the Nuclear Regulatory Commission (NRC) of a change in the Watts Bar Nuclear Plant, Unit 1, ECCS evaluation models for peak cladding temperature (PCT) in accordance with Title 10 of the Code of Federal Regulations, Section 50.46 related to a temporary change of more than 50 degrees Fahrenheit in calculated PCT.
The NRC staff has identified the enclosed Request for Additional Information which will be necessary in order to complete our review. Based on discussions with your staff, we understand that you expect to respond to this request by approximately August 18, 2006.
Sincerely,
/RA/
Douglas V. Pickett, Senior Project Manager Plant Licencing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-390
Enclosure:
As stated cc w/enclosure: See next page Distribution PUBLIC LPL2-2 r/f RidsNRRDorlLpl2-2 RidsNrrPMDPickett RidsNrrLACSola RidsOgcRp RidsAcrsAcnwMailCenter RidsRgn2MailCenter S. Sun, NRR RidsNrrDssSpwb ADAMS ACCESSION NO. ML061730232 NRR-088 OFFICE LPL2-2 LPL2-2/PM LPL2-2/LA SPWB/BC LPL2-2/BC NAME SCrane DPickett RSola HYi-Hsiung for JNakoski MMarshall DATE 06/26/06 06/26/06 06/26/06 06/30/06 06/30/06 OFFICIAL RECORD COPY
Mr. Karl W. Singer Tennessee Valley Authority WATTS BAR 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, 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. Michael D. Skaggs Site Vice President Watts Bar Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Spring City, TN 37381 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 Watts Bar Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Spring City, TN 37381 Mr. Jay Laughlin, Plant Manager Watts Bar Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Spring City, TN 37381 Senior Resident Inspector Watts Bar Nuclear Plant U.S. Nuclear Regulatory Commission 1260 Nuclear Plant Road Spring City, TN 37381 County Executive 375 Church Street Suite 215 Dayton, TN 37321 County Mayor P. O. Box 156 Decatur, TN 37322 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 Ms. Ann P. Harris 341 Swing Loop Road Rockwood, Tennessee 37854
REQUEST FOR ADDITIONAL INFORMATION WATTS BAR NUCLEAR PLANT UNIT 1 EMERGENCY CORE COOLING SYSTEM (ECCS) EVALUATION MODEL CHANGES DOCKET NO. 50-390 By letter dated August 16, 2005, the Tennessee Valley Authority (licensee), notified the Nuclear Regulatory Commission (NRC) staff of a change in the Watts Bar Nuclear Plant, Unit 1, ECCS evaluation models for peak cladding temperature (PCT) in accordance with Title 10 of the Code of Federal Regulations, Section 50.46 related to a temporary change of more than 50 degrees Fahrenheit (EF) in calculated PCT. The letter indicated that leakage in the piping relief valves could result in a loss of up to 30 gallons per minute (gpm) in Safety Injection (SI) flow to the pressurizer relief tank when the SI system was in operation. The licensee proposed PCT penalties for the small-break and large-break loss-of-coolant-accident (LOCA) analysis of 120 EF and 0 EF, respectively, to account for the effect of a reduction of 30 gpm in SI flow.
Please discuss how the PCT penalties were determined to account for the reduction of 30 gpm in SI flow. The discussion should include a description of the methodologies or computer codes used for the PCT penalty determination and the values of key plant parameters that are different from those used in the analysis of record for the LOCA analysis. Also, confirm that the methodologies or computer codes used for the PCT penalty determination were previously approved by the NRC, or justify the adequacy of the methodologies or computer codes used if they were not previously approved by the NRC.