ML072360435

RAI Related to Revision of Local Power Range Monitor Calibration Frequency

ML072360435
Person / Time
Site:	Clinton
Issue date:	09/20/2007
From:	Sands S NRC/NRR/ADRO/DORL/LPLIII-2
To:	Crane C AmerGen Energy Co
Sands S,NRR/DORL, 415-3154
References
TAC MD3795
Download: ML072360435 (5)

Text

September 20, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

CLINTON POWER STATION, UNIT NO. 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO REVISION OF LOCAL POWER RANGE MONITOR CALIBRATION FREQUENCY (TAC NO. MD3795)

Dear Mr. Crane:

By letter to the Nuclear Regulatory Commission (NRC) dated December 12, 2006, AmerGen Energy Company, LLC submitted a request to modify Technical Specification Surveillance Requirements (SR) 3.3.1.1.8 and SR 3.3.1.3.2, by increasing the surveillance interval of the local power range monitor calibration frequency from 1000 megawatt-days per ton (MWD/T) average core exposure, to 2000 MWD/T average core exposure, for the Clinton Power Station, Unit No. 1.

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 June 04, 2007, it was agreed that you would provide a response by no later than October 10, 2007, in order to support the current schedule for completion of the NRC staff review.

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) 415-3154.

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

September 20, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer AmerGen Energy Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

CLINTON POWER STATION, UNIT NO. 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO REVISION OF LOCAL POWER RANGE MONITOR CALIBRATION FREQUENCY (TAC NO. MD3795)

Dear Mr. Crane:

By letter to the Nuclear Regulatory Commission (NRC) dated December 12, 2006, AmerGen Energy Company, LLC submitted a request to modify Technical Specification Surveillance Requirements (SR) 3.3.1.1.8 and SR 3.3.1.3.2, by increasing the surveillance interval of the local power range monitor calibration frequency from 1000 megawatt-days per ton (MWD/T) average core exposure, to 2000 MWD/T average core exposure, for the Clinton Power Station, Unit No. 1.

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 June 04, 2007, it was agreed that you would provide a response by no later than October 10, 2007, in order to support the current schedule for completion of the NRC staff review.

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) 415-3154.

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 DISTRIBUTION:

PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 RidsNrrPMSSands RidsNrrLAEWhitt RidsAcrsAcnwMailCenter RidsOgcRp RidsRgn3MailCenter RidsNrrDorlDpr ADAMS Accession Number: ML072360435 NRR-088 OFFICE LPL3-2/PM LPL3-2/LA LPL3-2/BC NAME SSands EWhitt RGibbs DATE 9/18/07 9/18/07 9/20/07 OFFICIAL RECORD COPY

Clinton Power Station, Unit No. 1 cc:

Senior Vice President - Operations Support J. W. Blattner via e-mail Project Manager via e-mail Illinois Emergency Management Agency Division of Disaster Assistance &

Preparedness via e-mail Director - Licensing and Regulatory Affairs via e-mail Manager Licensing - Dresden, Quad Cities and Clinton via e-mail Manager Regulatory Assurance - Clinton via e-mail Vice President - Regulatory Affairs via e-mail Document Control Desk - Licensing via e-mail Site Vice President - Clinton Power Station via e-mail Plant Manager - Clinton Power Station via e-mail Senior Vice President - Midwest Operations via e-mail Resident Inspector U.S. Nuclear Regulatory Commission via e-mail Associate General Counsel via e-mail Chairman of DeWitt County c/o County Clerks Office DeWitt County Courthouse Clinton, IL 61727

REQUEST FOR ADDITIONAL INFORMATION CLINTON POWER STATION, UNIT NO. 1 DOCKET NO. 50-461 In reviewing AmerGen Energy Companys submittal dated January 12, 2007, related to your request to modify Technical Specification (TS) 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, for the Clinton Power Station, Unit No. 1 (Clinton), the NRC staff has determined that the following information is needed in order to complete its review:

1. Confirm that the change in LPRM calibration frequency continues to allow the 25 percent extension of the calibration interval as stated in the TS provisions in SR 3.0.2.

2. Provide the analysis that shows that the LPRM response uncertainty remains bounded by the minimum critical power ratio (MCPR) safety limits at 2500 MWD/T. In light of current operating strategies at Clinton, this analysis will need to demonstrate:

(a) The currently licensed safety limit MCPR is based on power distribution uncertainties that are consistent with the referenced technical basis documentation.

(b) A sufficient data base exists to cover the 2500 MWD/T calibration interval, because some of the referenced documentation is based on exposure measured in effective full-power hours rather than MWD/T, and assuming a 1:1 conversion between the two is non-conservative.

(c) The safety limit MCPR is licensed consistent with current General Electric interim methods employed at plants operating with expanded operating domains.