ML080990668
| ML080990668 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 03/04/2008 |
| From: | Cline B, Reese A Global Nuclear Fuel |
| 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 GNF Non-Proprietary Information 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:
Verification Status:
TSD NF-B343, Rev. 0 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.
Verified Information Page 2 of 5 Verified Information Page 2 of 5
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 Verified Information Page 3 of 5 Verified 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.
Verified Information Page 4 of 5
GNF S-0000-0082-2744 Rev 0 GNF Non-Proprietary Information Class I Figure 1 LPRM Calibration as a function of LPRM exposure Verified Information Page 5 of 5 Verified Information Page 5 of 5