ML080520391
| ML080520391 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 02/28/2008 |
| From: | Sands S NRC/NRR/ADRO/DORL/LPLIII-2 |
| To: | Pardee C Exelon Generation Co |
| Sands S,NRR/DORL, 415-3154 | |
| References | |
| TAC MD3795 | |
| Download: ML080520391 (5) | |
Text
February 28, 2008 Mr. Charles G. Pardee Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
CLINTON POWER STATION, UNIT NO. 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST TO REVISE LOCAL POWER RANGE MONITOR CALIBRATION FREQUENCY (TAC NO.
MD3795)
Dear Mr. Pardee:
By letter to the Nuclear Regulatory Commission (NRC) dated December 12, 2006, AmerGen Energy Company, LLC submitted an amendment request to Appendix A, technical specifications of Facility Operating License No. NPF-62 for Clinton Power Station (CPS), Unit No. 1.
Specifically, the submittal requests changes which will revise surveillance requirements (SR) 3.3.1.1.8 and SR 3.3.1.3.2, to increase the interval between local power range monitor calibrations from 1000 megawatt-days per ton (MWD/T) average core exposure to 2000 MWD/T average core exposure.
The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on February 25, 2008, it was agreed that you would provide a response within 30 days from the date of this letter.
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 NRC=s 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) 415-3154.
Sincerely,
/RA/
Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-461
Enclosure:
Request for Additional Information cc w/encl: See next page
February 28, 2008 Mr. Charles G. Pardee Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
CLINTON POWER STATION, UNIT NO. 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST TO REVISE LOCAL POWER RANGE MONITOR CALIBRATION FREQUENCY (TAC NO.
MD3795)
Dear Mr. Pardee:
By letter to the Nuclear Regulatory Commission (NRC) dated December 12, 2006, AmerGen Energy Company, LLC submitted an amendment request to Appendix A, technical specifications of Facility Operating License No. NPF-62 for Clinton Power Station (CPS), Unit No, 1.
Specifically, the submittal requests changes which will revise surveillance requirements (SR) 3.3.1.1.8 and SR 3.3.1.3.2, to increase the interval between local power range monitor calibrations from 1000 megawatt-days per ton (MWD/T) average core exposure to 2000 MWD/T average core exposure.
The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on February 25, 2008, it was agreed that you would provide a response within 30 days from the date of this letter.
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 NRC=s 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) 415-3154.
Sincerely,
/RA/
Stephen P. Sands, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-461
Enclosure:
Request for Additional Information cc w/encl: See next page DISTRIBUTION:
PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 RidsOgcRp RidsNrrPMSSands RidsNrrLAEWhitt RidsRgn3MailCenter RidsNrrDorlDpr RidsNrrDssSpwb RidsAcrsAcnw&mMailCenter ADAMS Accession Number: ML080520391 OFFICE LPL3-2/PM LPL3-2/LA LPL3-2/BC NAME SSands EWhitt RGibbs DATE 2/28/08 2/28/08 2/28/08 OFFICIAL RECORD COPY
Clinton Power Station, Unit No. 1 cc:
Corporate Distribution Exelon Generation Company, LLC Via e-mail Clinton Distribution Exelon Generation Company, LLC Via e-mail Clinton Senior Resident Inspector U.S. Nuclear Regulatory Commission Via e-mail Illinois Emergency Management Agency Division of Disaster Assistance &
Preparedness Via e-mail J. W. Blattner, Project Manager Sargent & Lundy Engineers Via e-mail Chairman of DeWitt County c/o County Clerks Office Via e-mail
Enclosure REQUEST FOR ADDITIONAL INFORMATION CLINTON POWER STATION, UNIT NO. 1 DOCKET NO. 50-461 In reviewing the December 12, 2006 (Agencywide Documents Access and Management System Accession No. ML063470222), AmerGen Energy Company, LLC submittal regarding an amendment to Appendix A, technical specifications (TS) for Clinton Power Station (CPS), Unit No. 1, the Nuclear Regulatory Commission (NRC) staff has identified issues which will require resolution. Specifically, the submittal requests changes which will revise surveillance requirements (SR) 3.3.1.1.8 and SR 3.3.1.3.2, to increase the interval between local power range monitor (LPRM) calibrations from 1000 megawatt-days per ton (MWD/T) average core exposure to 2000 MWD/T average core exposure. Hence, additional information is required for the NRC staff to complete its review.
First, the NRC staff finds the basis that the LPRM uncertainty increases associated with the requested calibration interval extension are bounded by the General Electric Thermal Analysis Basis (GETAB) to be inapplicable in its entirety, because the GETAB has been supplanted, for this purpose, by Global Nuclear Fuel's Safety Limit Minimum Critical Power Ratio Topical Reports, NEDC-32601P-A, "Methodology and Uncertainties for Safety Limit Minimum Critical Power Ratio Calculations," and NEDC-32694P-A, "Power Distribution Uncertainties for Safety Limit Minimum Critical Power Ratio Calculations."
Second, the referenced precedential amendment requests are inapplicable because they were approved prior to referencing of the supplanting topical reports listed above.
The NRC staff has also identified a need for additional information with respect to the two items listed above.
- 1.
Perform a CPS-specific safety limit minimum critical power ratio (SLMCPR) calculation using a bounding LPRM update uncertainty parameter. Identify the parameter used, the NRC-approved method to calculate the SLMCPR, the change in SLMCPR, and confirm whether the currently licensed SLMCPR will adequately cover the increase in uncertainty.
Justify that the uncertainty parameter is bounding of the requested surveillance interval, based on observed LPRM detector behavior.
- 2.
Confirm that a similar increase to nodal power uncertainty used for mechanical analyses will remain within the applicable limit. Identify the uncertainty value, its analytical limit, and how much it would increase as a result of extended LPRM calibrations.
- 3.
Confirm that the units used in any evaluations or demonstrations that are based on neutron flux or core exposure are analogous to the fuel burn-up levels (MWD/T) licensed in the CPS TSs.
- 4.
Confirm that the analytic and statistical treatments requested above are also bounding of the TS 25 percent grace, i.e., to 2500 MWD/T.
Enclosure