ML071060029
| ML071060029 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 04/26/2007 |
| From: | Gratton C NRC/NRR/ADRO/DORL/LPLIII-2 |
| To: | Crane C Exelon Generation Co |
| Gratton C, NRR/DORL 415-1055 | |
| References | |
| TAC MD2371, TAC MD2372 | |
| Download: ML071060029 (5) | |
Text
April 26, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
BYRON STATION, UNIT NOS. 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO REQUEST TO CHANGE THE TORNADO MISSILE PROTECTION METHODOLOGY (TAC NOS. MD2371 AND MD2372)
Dear Mr. Crane:
By letter to the Nuclear Regulatory Commission (NRC) dated June 16, 2006, as supplemented by letter dated September 14, 2006, Exelon Generation Company, LLC (the licensee),
submitted a license amendment request to approve the use of TORMIS for tornado missile protection analysis at Byron Station, Unit Nos. 1 and 2.
The NRC staff is reviewing the information contained in the letters and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter, a draft of which was sent by facsimile to Mr. David Chrzanowski of your staff on April 12, 2007. During a call on April 24, 2007, Mr. Chrzanowski indicated that a followup call was not needed to clarify the intent of the NRC staff questions.
The NRC staff requests that you respond to the enclosed information request by May 10, 2007.
The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1055.
Sincerely,
/RA/
Christopher Gratton, Senior Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-454 and STN 50-455,
Enclosure:
Request for Additional Information cc w/encl: See next page
Mr. Christopher M. Crane April 26, 2007 President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
BYRON STATION, UNIT NOS. 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO REQUEST TO CHANGE THE TORNADO MISSILE PROTECTION METHODOLOGY (TAC NOS. MD2371 AND MD2372)
Dear Mr. Crane:
By letter to the Nuclear Regulatory Commission (NRC) dated June 16, 2006, as supplemented by letter dated September 14, 2006, Exelon Generation Company, LLC (the licensee),
submitted a license amendment request to approve the use of TORMIS for tornado missile protection analysis at Byron Station, Unit Nos. 1 and 2.
The NRC staff is reviewing the information contained in the letters and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter, a draft of which was sent by facsimile to Mr. David Chrzanowski of your staff on April 12, 2007. During a call on April 24, 2007, Mr. Chrzanowski indicated that a followup call was not needed to clarify the intent of the NRC staff questions.
The NRC staff requests that you respond to the enclosed information request by May 10, 2007.
The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRCs goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1055.
Sincerely,
/RA/
Christopher Gratton, Senior Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. STN 50-454 and STN 50-455
Enclosure:
Request for Additional Information cc w/encl: See next page DISTRIBUTION:
PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 RidsNrrPMCGratton RidsNrrLAEWhitt RidsAcrsAcnwMailCenter RidsOgcRp RidsDeEmcb RidsRgn3MailCenter RidsNrrDorlDpr RidsNrrPMRKuntz TBloomer, EDO Region III RidsNrrDssSbpb ZXi, NRR JTatum, NRR ESmith, NRR ADAMS ACCESSION #: ML071060029 OFFICE LPL3-2/PM LPL3-2/LA DE/EMCB/BC LPL3-2/BC NAME CGratton EWhitt KManoly RGibbs DATE 4/25/07 4/25/07 4/25/07 4/26/07 OFFICIAL RECORD COPY
REQUEST FOR ADDITIONAL INFORMATION BYRON STATION, UNIT NOS. 1 AND 2 DOCKET NOS. STN 50-454 AND STN 50-455 The following questions pertain to your application dated June 16, 2006, as supplemented by your letter dated September 14, 2006:
- 1.
The licensees response to issue 11 in its letter dated September 14, 2006, explains the methodology for conversion of the soil thickness to an equivalent thickness of concrete.
Please provide the minimum soil thickness, as well equivalent concrete thickness, which is adequate to protect the buried piping from tornado generated missiles.
- 2.
The licensees response to issue 11 also indicates that the tornado wind and differential pressure effects on the soil are not accounted for. Since a soil barrier, which cannot be modeled by TORMIS, is not as stable as concrete or steel barriers, the vortex of the tornado can remove some amount of the soil over the area in question. Regulatory Guide 1.76 calls out the design-basis tornado characteristics including pressure drop due to tornados. Please address the possibility that the tornado vortex may remove a certain amount of the soil cover and provide an estimate of the soil thickness that can be removed.
Enclosure
Byron Station, Unit Nos. 1 and 2 cc:
Regional Administrator, Region III U.S. Nuclear Regulatory Commission 2443 Warrenville Road, Suite 210 Lisle, IL 60532-4351 Illinois Emergency Management Agency Division of Disaster Assistance &
Preparedness 110 East Adams Street Springfield, IL 62701-1109 Document Control Desk - Licensing Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Mr. Dwain W. Alexander, Project Manager Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, PA 15230 Howard A. Learner Environmental Law and Policy Center of the Midwest 35 East Wacker Drive Suite 1300 Chicago, IL 60601-2110 U.S. Nuclear Regulatory Commission Byron Resident Inspectors Office 4448 North German Church Road Byron, IL 61010-9750 Ms. Lorraine Creek RR 1, Box 182 Manteno, IL 60950 Chairman, Ogle County Board P.O. Box 357 Oregon, IL 61061 Mrs. Phillip B. Johnson 1907 Stratford Lane Rockford, IL 61107 Attorney General 500 S. Second Street Springfield, IL 62701 Plant Manager - Byron Station Exelon Generation Company, LLC 4450 N. German Church Road Byron, IL 61010-9794 Site Vice President - Byron Station Exelon Generation Company, LLC 4450 N. German Church Road Byron, IL 61010-9794 Senior Vice President - Operations Support Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Chairman Will County Board of Supervisors Will County Board Courthouse Joliet, IL 60434 Director - Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Manager Regulatory Assurance - Byron Exelon Generation Company, LLC 4450 N. German Church Road Byron, IL 61010-9794 Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Vice President - Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
Byron Station, Unit Nos. 1 and 2 cc:
Manager Licensing - Braidwood, Byron and LaSalle Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President - Midwest Operations Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Mr. Barry Quigley 3512 Louisiana Rockford, IL 61108