ML080990668

License Amendment Request - Revised LPRM Calibration Frequency Supplemental Response - Global Nuclear Fuel Report - Gnf S-0000-0082-2744, Rev. 0, Limerick LPRM Calibration Interval Extension Support, (Non-Proprietary Version)

ML080990668
Person / Time
Site:	Limerick
Issue date:	03/04/2008
From:	Cline B, Reese A Global Nuclear Fuel - Americas
To:	Office of Nuclear Reactor Regulation
References
TSD NF-B343, Rev 0 GNF S-0000-0082-2744, Rev 0
Download: ML080990668 (6)

Text

ATTACHMENT 2 Limerick Generating Station Units 1 and 2 Docket Nos. 50-352 and 50-353 License Amendment Request Revise LPRM Calibration Interval Global Nuclear Fuel Report GNF S-0000-0082-2744, Rev. 0 Limerick LPRM Calibration Interval Extension Support Non-Proprietary Version

GNF Global Nuclear Fuel A Joint Venture of GE, Toshiba, & Hitachi P. 0. Box 780, Wilmington, NC 28402-0780, USA GNFNon-ProprietaryInformation Class I GNF S-0000-0082-2744 Rev 0 March 4, 2008 Limerick LPRM Calibration Interval Extension Support Responsible Engineer:

Bill Cline Approving Manager:

A. P. Reese Authorizing Document: TSD NF-B343, Rev. 0 Verification Status: Verified

GNF S-0000-0082-2744 Rev 0 GNF Non-Proprietary Information Class I Proprietary Information Notice This document is the GNF non-proprietary version of the GNF proprietary report. From the GNF proprietary version, the information denoted as GNF proprietary (enclosed in double brackets) was deleted to generate this version.

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GNF S-0000-0082-2744 Rev 0 GNF Non-Proprietary Information Class I Limerick LPRM Calibration Interval Extension Support

Background

Exelon will be seeking a calibration interval extension for Limerick Units' LPRMs from the Nuclear Regulatory Commission (NRC). GNF is providing support as to the impact of such a change on the calculated Safety Limit MCPR. The following is the GNF response.

GNF Response As stated in the Technical Specifications basis regarding LPRM calibration interval requirement, "The 1000 MWD/T Frequency is based on operating experience with LPRM sensitivity changes." Figure 1 is a typical graph of the natural logarithm of the LPRM calibration current versus the LPRM exposure. ((

[31 Page 3 of 5 Verified Information Information Page 3 of 5

GNF S-0000-0082-2744 Rev 0 GNF Non-Proprietary Information Class I

{31))

The last sentence of Section 3.2 ofNEDC-32694P-A Rev.0 states:

((

{3)1}]

By doubling the LPRM update uncertainty, the total update uncertainty becomes:

Equation 3-3 of Section 3.3 of NEDC-32694P-A Rev. 0 then is used to fold the total update uncertainty into the total bundle power uncertainty:

(( 131))

Therefore, by doubling the LPRM update uncertainty, the total bundle power uncertainty becomes ((

For the Limerick plants, comparison between SLMCPR calculations using the original LPRM update uncertainty and the doubled LPRM update uncertainty shows an

ý31)) on the calculated SLMCPR value.

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GNF S-0000-0082-2744 Rev 0 GNF Non-Proprietary Information Class I Figure 1 LPRM Calibration as a function of LPRM exposure Page 5 of 5 Verified Information Information Page 5 of 5