ML080380222
| ML080380222 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/01/2008 |
| From: | Cowan P Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML080380222 (7) | |
Text
Exekn Exelon Nuclear www.exeloncorp.com 200 Exelon Way NucleaT Kennett Square, PA 19348 February 1, 2008 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 Docket Nos. 50-277 and 50-278
Subject:
License Amendment Request - Revise LPRM Calibration Frequency Supplemental Response Global Nuclear Fuel Report - GNF S-0000-0080-3313, Rev. 0, "PB LPRM Calibration Interval Extension Support"
References:
- 1)
Letter from P. B. Cowan, Exelon Generation Company, LLC, to U.S.
Nuclear Regulatory Commission, "License Amendment Request - Revise Local Power Range Monitor Calibration Frequency," dated November 17, 2006
- 2)
U.S. Nuclear Regulatory Commission e-mail dated August 15, 2007, for Peach Bottom Atomic Power Station, Units 2 and 3, draft Request for Additional Information Related to Exelon License Amendment Request Regarding Revisions to the Local Power Range Monitor Calibration Frequency (TAC Nos. MD3717/3718)
- 3)
Letter from P. B. Cowan, Exelon Generation Company, LLC, to U.S.
Nuclear Regulatory Commission, "Response to Request for Additional Information Concerning License Amendment Request to Revise Local Power Range. Monitor Calibration Frequency," dated September 21, 2007
- 4)
Letter from John D. Hughey, U.S. Nuclear Regulatory Commission, to Mr.
Charles G. Pardee, Exelon Generation Company, LLC, "Peach Bottom Atomic Power Station, Units 2 and 3, - Proposed Amendment to Extend Local Power Range Monitor Calibration Interval" (TAC Nos. MD3717 and MD3748), dated December 14, 2007
- 5)
Letter from P. B. Cowan, Exelon Generation Company, LLC, to U.S.
Nuclear Regulatory Commission, "License Amendment Request - Revise LPRM Calibration Frequency Global Nuclear Fuel Report - Exelon Nuclear LPRM Calibration Interval Increase for Peach Bottom Atomic Station, Units 2 and 3," dated December 21, 2007 transmitted herewith contains SUNSI. When separated from the attachment, this transmittal document is decontrolled.
U. S. Nuclear Regulatory Commission License Amendment Request - Revise LPRM Calibration Frequency Docket Nos. DPR-44 and DPR-56 February 1, 2008 Page 2 By letter dated November 17, 2006 (Reference 1), Exelon Generation Company, LLC (Exelon) requested changes to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS),
Units 2 and 3, respectively. The proposed changes would increase the interval between Local Power Range Monitor (LPRM) calibrations from 1000 megawatt-days/ton (MWD/T) to 2000 MWD/T.
In References 2 and 4, the NRC requested additional information concerning the PBAPS License Amendment Request (LAR). Exelon submitted responses to the NRC's request for additional information by letters dated September 21, 2007 (Reference 3) and December 21, 2007 (Reference 5).
Subsequently, during teleconference discussions with NRC, Exelon, and Global Nuclear Fuel (GNF) representatives on January 15, 2008, the NRC requested further clarification regarding LPRM uncertainty and sensitivity. As a result of the discussions, Exelon agreed to submit additional information.
Accordingly, attached is the requested LPRM analysis prepared by GNF that supports extending the nominal LPRM calibration interval from 1000 MWD/T to 2000 MWD/T. to this letter provides a copy of the GNF analysis (i.e., GNF Report S-0000-0080-3313, Rev. 0, "PB LPRM Calibration Interval Extension Support"), which GNF considers to contain proprietary information. The proprietary information is identified by bracketed text. GNF requests that the proprietary information in Attachment 1 be withheld from public disclosure, in accordance with the requirements of 10 CFR 9.17(a)(4) and 10 CFR 2.390(a)(4). An original signed affidavit supporting this request is included in Attachment 1 to this letter. Attachment 2 to this letter contains a non-proprietary version of the GNF analysis (GNF Report S-0000-0080-3313, Rev. 0).
Exelon has concluded that the information provided in this response does not impact the conclusions of the: 1) Technical Analysis, 2) No Significant Hazards Consideration under the standards set forth in 10 CFR 50.92(c), or 3) Environmental Consideration as provided in the Reference 1 letter.
There are no regulatory commitments contained within this letter. If you have any further questions or require additional information, please contact Richard Gropp at 610-765-5557.
U.S. Nuclear Regulatory Commission License Amendment Request - Revise LPRM Calibration Frequency Docket Nos. DPR-44 and DPR-56 February 1, 2008 Page 3 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 1st day of February 2008.
Respectfully, Pamela B. Cowan Director - Licensing and Regulatory Affairs Exelon Generation Company, LLC : Global Nuclear Fuel Report GNF S-0000-0080-3313, Rev. 0, "PB LPRM Calibration Interval Extension Support" (Proprietary Version and supporting Affidavit) : Global Nuclear Fuel Report GNF S-0000-0080-3313, Rev. 0, "PB LPRM Calibration Interval Extension Support" (Non-Proprietary Version) cc:
Regional Administrator - NRC Region I w/ Attachment 2 NRC Senior Resident Inspector - PBAPS NRC Project Manager, NRR - PBAPS Director, Bureau of Radiation Protection - Pennsylvania Department of Environmental Protection
ATTACHMENT 2 Peach Bottom Atomic Power Station Units 2 and 3 Docket Nos. 50-277 and 50-278 License Amendment Request Revise LPRM Calibration Interval Global Nuclear Fuel Report GNF S-0000-0080-3313. Rev. 0.
"PB LPRM Calibration Interval Extension Support" Non-Proprietary Version Non-Proprietary Information Page 1 of 3 GNF S-0000-0080-3313 Rev 0 PB LPRM Calibration Interval Extension Support
Background
Exelon will be seeking a calibration interval extension for the Peach Bottom 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. ((
1]
((
Page 2 of 3 Non-Proprietary Information GNF S-0000-0080-3313 Rev 0 The last sentence of Section 3.2 of NEDC-32694P-A Rev.0 states:
((I By doubling the LPRM update uncertainty, the total update uncertainty becomes:
((
]1 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:
Therefore, by doubling the LPRM update uncertainty, the total bundle power uncertainty becomes For the Peach Bottom plants, comparison between SLMCPR calculations using the original LPRM update uncertainty and the doubled LPRM update uncertainty shows an
)) on the calculated SLMCPR value.
Page 3 of 3 Non-Proprietary Information GNF S-0000-0080-3313 Rev 0 1]