ML043640207

Request for Additional Information, Activation of the Trip Outputs of the Oscillation Power Range Monitor Portion of the Neutron Monitoring System

ML043640207
Person / Time
Site:	Limerick
Issue date:	01/19/2005
From:	Travis Tate NRC/NRR/DLPM/LPD1
To:	Crane C Exelon Generation Co
Tate T, NRR/DLPM, 415-8474
References
TAC MC3430, TAC MC3431
Download: ML043640207 (5)

Text

January 19, 2005 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION (RAI) RE: ACTIVATION OF THE TRIP OUTPUTS OF THE OSCILLATION POWER RANGE MONITOR PORTION OF THE NEUTRON MONITORING SYSTEM (TAC NOS. MC3430 AND MC3431)

Dear Mr. Crane:

By application dated May 20, 2004, Exelon Generation Company, LLC, requested license amendments for Limerick Generating Station, Units 1 and 2, related to the activation of the trip outputs of the oscillation power range monitor portion of the power range neutron monitoring system. The Nuclear Regulatory Commission staff is reviewing the request and has determined that additional information is needed to complete the review.

The specific information requested was transmitted by email to Mr. Glenn Stewart of your staff on December 22, 2004. The requested information was discussed with your staff on January 11, 2005. The questions enclosed with this letter reflect those emailed with minor editorial corrections.

The staff requests that you provide the requested information within 30 days from the date of this letter. If circumstances result in the need to revise the response date, please contact me at (301) 415-8474.

Sincerely,

/RA/

Travis L. Tate, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

RAI cc w/encl: See next page

Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

SUBJECT:

LIMERICK GENERATING STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION (RAI) RE: ACTIVATION OF THE TRIP OUTPUTS OF THE OSCILLATION POWER RANGE MONITOR PORTION OF THE NEUTRON MONITORING SYSTEM (TAC NOS. MC3430 AND MC3431)

Dear Mr. Crane:

By application dated May 20, 2004, Exelon Generation Company, LLC, requested license amendments for Limerick Generating Station, Units 1 and 2, related to the activation of the trip outputs of the oscillation power range monitor portion of the power range neutron monitoring system. The Nuclear Regulatory Commission staff is reviewing the request and has determined that additional information is needed to complete the review.

The specific information requested was transmitted by email to Mr. Glenn Stewart of your staff on December 22, 2004. The requested information was discussed with your staff on January 11, 2005. The questions enclosed with this letter reflect those emailed with minor editorial corrections.

The staff requests that you provide the requested information within 30 days from the date of this letter. If circumstances result in the need to revise the response date, please contact me at (301) 415-8474.

Sincerely,

/RA/

Travis L. Tate, Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-352 and 50-353

Enclosure:

RAI cc w/encl: See next page DISTRIBUTION:

PUBLIC PDI-2 R/F DRoberts TTate HGarg GMatakas, RI OGC ACRS MOBrien MRazzaque DLPM DPR EMarinos FAkstulewicz Accession Number: ML043640207 OFFICE PDI-2/PM PDI-2/LA PDI-2/SC NAME TTate MOBrien DRoberts DATE 1/19/05 1/19/05 1/19/05 Official Record Copy

Limerick Generating Station, Unit Nos. 1 and 2 cc:

Site Vice President Associate General Counsel Limerick Generating Station Exelon Generation Company, LLC Exelon Generation Company, LLC 4300 Winfield Road P.O. Box 2300 Warrenville, IL 60555 Sanatoga, PA 19464 Correspondence Control Desk Plant Manager Exelon Generation Company, LLC Limerick Generating Station P.O. Box 160 Exelon Generation Company, LLC Kennett Square, PA 19348 P.O. Box 2300 Sanatoga, PA 19464 Regional Administrator, Region I U.S. Nuclear Regulatory Commission Regulatory Assurance Manager - Limerick 475 Allendale Road Exelon Generation Company, LLC King of Prussia, PA 19406 P.O. Box 2300 Sanatoga, PA 19464 Senior Resident Inspector U.S. Nuclear Regulatory Commission Senior Vice President - Nuclear Services Limerick Generating Station Exelon Generation Company, LLC P.O. Box 596 4300 Winfield Road Pottstown, PA 19464 Warrenville, IL 60555 Library Vice President - Operations, Mid-Atlantic U.S. Nuclear Regulatory Commission Exelon Generation Company, LLC Region I 200 Exelon Way, KSA 3-N 475 Allendale Road Kennett Square, PA 19348 King of Prussia, PA 19406 Vice President Chief-Division of Nuclear Safety Licensing and Regulatory Affairs PA Dept. of Environmental Resources Exelon Generation Company, LLC P.O. Box 8469 4300 Winfield Road Harrisburg, PA 17105-8469 Warrenville, IL 60555 Chairman Director Board of Supervisors of Limerick Township Licensing and Regulatory Affairs 646 West Ridge Pike Exelon Generation Company, LLC Linfield, PA 19468 200 Exelon Way, KSA 3-E Kennett Square, PA 19348 Dr. Judith Johnsrud National Energy Committee Manager Licensing Sierra Club Limerick Generating Station 433 Orlando Avenue Exelon Generation Company, LLC State College, PA 16803 200 Exelon Way, KSA 3-E Kennett Square, PA 19348

REQUEST FOR ADDITIONAL INFORMATION LIMERICK GENERATING STATION, UNITS 1 AND 2 REGARDING REQUEST FOR LICENSE AMENDMENTS DATED MAY 20, 2004 RELATED TO ACTIVATION OF THE TRIP OUTPUTS OF THE OSCILLATION POWER RANGE MONITOR PORTION OF THE NEUTRON MONITORING SYSTEM

1. The delta critical power ratio over initial minimum critical power ratio versus oscillation magnitude (DIVOM) curve is used to calculate a final minimum critical power ratio (MCPR). If this calculated MCPR value is greater than the safety limit MCPR, then the licensing criterion is considered to have been met. Please describe the DIVOM correlation that will be used to determine the oscillation power range monitor (OPRM) scram set points. The response should include the following information:

a. Will a generic DIVOM correlation be used or will a plant cycle-specific correlation be developed? Please demonstrate that the DIVOM curve used is the limiting one.

b. If a plant cycle-specific DIVOM curve was developed for the next cycle, please describe how it was derived including whether any approved methodologies used, and whether the slope of the curve is conservative.

c. Provide specific values for the OPRM scram setpoints and the DIVOM correlation for the next cycle and discuss its applicability to the range of power operation.

2. a. In Table 3.3.1-1, Reactor Protection System Instrumentation Action Statements, proposed action 10a states that if the condition exists due to a common-mode OPRM deficiency, then an alternate method to detect and suppress oscillations is initiated. Please describe the alternate method.

b. Backup stability protection (BSP) may be used when the Option III OPRM system is temporarily inoperable. The BSP regions are confirmed on a plant cycle-specific basis to provide consistency with the long-term solution (LTS) general requirement of long-term applicability. Please identify the differences between the proposed BSP and interim corrective actions (ICA) being used currently. Also describe the Limerick BSP system in detail, including its applicability to the range of power operation.

3. Was the OPRM portion of the power range neutron monitoring (PRNM) system in test mode before the trip outputs were activated? If so, please describe any lessons learned during the testing period of the system. Please include any changes that were necessary in order to avoid spurious scrams at Limerick 1 and 2 and whether deviations Enclosure

from the Nuclear Regulatory Commission-approved methodology, if any, were conservative?

4. Attachment 1, Page 2 of 15, item A, states that there are no allowable values associated with the OPRM upscale trip function. Please explain how the operability of the OPRM upscale function is determined in the absence of the allowable values. If some other number has been used by the procedure, then explain how this meets the requirements of Title 10 of the Code of Federal Regulations (10 CFR), Section 50.36(c)(1)(ii)(A).

5. In order to ensure that the proposed OPRM trip will perform its intended design functions, the equipment should be qualified for all environmental conditions where it is installed as required by General Design Criterion 4 of Appendix A to Part 50 of 10 CFR (10 CFR Part 50). Therefore, please confirm that the OPRM equipment at Limerick 1 and 2 has been qualified for electromagnetic interference (EMI) and radio frequency interference (RFI) based on either the worst case EMI/RFI levels at its installed location or using the generic levels identified in the Electric Power Research Institutes Report, TR-102323, Guidelines for Electromagnetic Interference Testing in Power Plants, and Regulatory Guide 1.180, Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems, dated October 2003.