ML050630284
| ML050630284 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/23/2005 |
| From: | Braun R Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML050630284 (2) | |
Text
ExelonM Exelon Nuclear Telephone 717.456.7014 Nuclear Peach Bottom Atomic Power Station www.exeloncorp.com 1848 Lay Road Delta, PA 17314-9032 10 CFR 50.90 February 23, 2005 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Units 2 and 3 Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278
Subject:
Supplemental Response to Request for Additional Information concerning License Amendment Request - Activation of the Trip Outputs of the Oscillation Power Range Monitor Portion of the Power Range Neutron Monitoring System
References:
(1) Letter from M. P. Gallagher, Exelon Generation Company, LLC, to U. S.
Nuclear Regulatory Commission, dated February 27, 2004 (2) Letter from G. F. Wunder, U. S. Nuclear Regulatory Commission, to C. M.
Crane, Exelon Generation Company, LLC, dated August 13, 2004.
(3) Letter from M. P. Gallagher, Exelon Generation Company, LLC, to U. S.
Nuclear Regulatory Commission, dated September 13, 2004 In Reference 1, Exelon Generation Company, LLC (Exelon), requested a change to the Technical Specifications (TS), Appendix A, of Facility Operating License Nos. DPR-44 and DPR-56 for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, respectively. The proposed change supports the activation of the trip outputs of the previously-installed Oscillation Power Range Monitor (OPRM) portion of the General Electric (GE) Nuclear Measurement Analysis and Control (NUMAC) Power Range Neutron Monitoring (PRNM) system.
In Reference 2, the NRC requested additional information concerning the Reference 1 submittal, including a request that Exelon provide specific values for the OPRM trip setpoints and the Delta Critical Power Ratio/Initial Critical Power Ratio Versus Oscillation Magnitude (DIVOM) correlation for the next cycle. The requested information was provided to the NRC by Reference 3, with one exception.
The evaluation of the initial plantlcycle-specific DIVOM correlation and OPRM trip setpoints for PBAPS was not complete at the time. Reference 3 indicated that Exelon would provide these values once the evaluation was complete.
The evaluation has since been completed. The requested values are provided as described below for information only since they will be incorporated into the PBAPS Core Operating Limits Report (COLR) as indicated in References 1 and 3.
Supplemental Response to Request for Additional Information Peach Bottom OPRM Trip Activation LAR February 23, 2005 Page 2 A PBAPS specific analysis was performed to determine a DIVOM curve that was applicable to the current PBAPS, Unit 2 and Unit 3, operating cycles (i.e., Cycle 16 for PBAPS, Unit 2, and Cycle 15 for PBAPS, Unit 3) during which the OPRM trip function will be activated pending NRC approval of the requested amendments. The DIVOM analysis was performed for the power/flow state point, corresponding to a post two-pump trip condition at 30% rated core flow (natural circulation) along the highest licensed rod line, i.e., the Maximum Extended Load Line Limit Analysis (MELLLA) rod line. The limiting exposure condition was identified and utilized to bound the entire operating cycle. The limiting DIVOM slope for PBAPS, Unit 2, Cycle 16, and PBAPS, Unit 3, Cycle 15, was determined to be 0.50.
A calculation of the OPRM Amplitude Trip Setpoints (Sp), and associated OPRM Confirmation Count Trip Setpoints (Np), was performed.
The OPRM trip setpoints are a function of the calculated DIVOM slope and the cycle specific Operating Limit Minimum Critical Power Ratio (OLMCPR) and Safety Limit Minimum Critical Power Ratio (SLMCPR). A more conservative DIVOM slope of 0.575 (vs. the calculated value of 0.50) was utilized in the OPRM trip setpoint calculations.
Based on the PBAPS, Unit 2, Cycle 16, cycle specific parameters, the required OPRM Amplitude Trip Setpoint (Sp) was determined to be 1.13. The associated OPRM Confirmation Count Trip Setpoint (Np) was determined to be 15. Based on the PBAPS, Unit 3, Cycle 15, cycle specific parameters, the required OPRM Amplitude Trip Setpoint (Sp) was determined to be 1.13. The associated OPRM Confirmation Count Trip Setpoint (Np) was determined to be 15.
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 original submittal (Reference 1).
There are no regulatory commitments contained within this letter.
If you have any questions or require additional information, please contact Glenn Stewart at 610-765-5529.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the 23rd day of February, 2005.
Respectfully, Robert C. Braun Site Vice President Peach Bottom Atomic Power Station Exelon Generation Company, LLC cc:
Regional Administrator - NRC Region I NRC Senior Resident Inspector - PBAPS NRC Project Manager, NRR - PBAPS Director, Bureau of Radiation Protection - PA Department of Environmental Protection CCN: 05-14016