ML080280174

Licensed Thermal Power, Byron Station, Unit 1 - Request for Additional Information

ML080280174
Person / Time
Site:	Byron
Issue date:	07/08/2003
From:	Dick G Office of Nuclear Reactor Regulation
To:	Skolds J Exelon Generation Co, Exelon Nuclear
References
FOIA/PA-2008-0046, TAC MB7378
Download: ML080280174 (5)

Text

UNITED STATES/

NUCLEAR REGULATORY COMMISSION VT-1 WASHINGTON, D.C. 20555-0001 July 8, 2003 Mr. John L. Skolds, President Exelon Nuclear Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 SUBJECTi LICENSED THERMAL POWER, BYRON STATION, UNIT 1- REQUEST FOR ADDITIONAL INFORMATION (TAC NO. MB7378)

Dear Mr. Skolds:

The Nuclear Regulatory Commission (NRC) staff is reviewing the February 5, 2003, response of Exelon Company, LLC (Exelon), to the NRC's letter of January 22, 2003. During the review, the staff has determined that it requires additional information in order to fully resolve the question of the licensed power limit for Byron Station, Unit 1. The request for additional information (RAI) is attached.

Based on a discussion of the questions with Exelon staff members on June 20, 2003, we request that the response to the attached RAI be received by August 15, 2003.

Sincerely, Ge~oroF .Dick, Jr., Project Manager, Section 2 Project Directorate IIl Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. STN 50-454

Enclosure:

As stated cc w/encl: See next page A do 425

Byron Station Units 1 and 2 cc:

Regional Administrator, Region III Attorney General U.S. Nuclear Regulatory Commission 500 S. Second Street 801 Warrenville Road Springfield, IL 62701 Lisle, IL 60532-4351 Byron Station Manager Illinois Department of Nuclear Safety Exelon Generation Company, LLC Office of Nuclear Facility Safety 4450 N. German Church Road 1035 Outer Park Drive Byron, IL 61010-9794 Springfield, IL 62704 Site Vice President - Byron Document Control Desk-Licensing Exelon Generation Company, LLC Exelon Generation Company, LLC 4450 N. German Church Road 4300 Winfield Road Byron, IL 61010-9794 Warrenville, IL 60555 Senior Vice President - Nuclear Services Ms. C. Sue Hauser, Project Manager Exelon Generation Company, LLC Westinghouse Electric Corporation 4300 Winfield Road Energy Systems Business Unit Warrenville, IL 60555 Post Office Box 355 Pittsburgh, PA 15230 Vice President Mid-West Operations Support Joseph Gallo Exelon Generation Company, LLC Gallo & Ross 4300 Winfield Road 1025 Connecticut Ave., NW, Suite 1014 Warrenville, IL 60555 Washington, DC 20036 Senior Vice President Howard A. Learner Mid-West Regional Operating Group Environmental Law and Policy Exelon Generation Company, LLC Center of the Midwest 4300 Winfield Road 35 East Wacker Drive Warrenville, IL 60555 Suite 1300 Chicago, IL 60601-2110 Chairman Will County Board of Supervisors U.S. Nuclear Regulatory Commission Will County Board Courthouse Byron Resident Inspectors Office Joliet, Illinois 60434 4448 North German Church Road Byron, IL 61010-9750 Ms. Lorraine Creek RR 1, Box 182 Manteno, IL 60950 Chairman, Ogle County Board Post Office Box 357 Oregon, IL 61061 Mrs. Phillip B. Johnson 1907 Stratford Lane Rockford, IL 61107

Byron Station Units 1 and 2 - P-Illinois Emergency Management Agency Division of Disaster Assistance &

Preparedness 110 East Adams Street Springfield, Illinois 62701-1109 Director Licensing Mid-West Regional Operating Group Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Regulatory Assurance Manager - Byron Exelon Generation Company, LLC 4450 N. German Church Road Byron, IL 61010-9794 Senior Counsel, Nuclear Mid-West Regional Operating Group Exelon Generation Company, LLC 4300.Winfield Road Warrenville, IL 60555 Vice President Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Manager Licensing - Braidwood and Byron Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE BYRON UNIT 1, THERMAL POWER LIMIT EXELON GENERATION COMPANY, LLC BYRON STATION, UNIT 1 DOCKET NO. STN 50-454 The NRC staff is reviewing the licensee's response of February 5, 2003, to the NRC's letter of January 22, 2003. During the review, the staff has determined that it requires additional information in order to fully resolve the question of the licensed power limit for Byron Station, Unit 1. The staff's questions or information needs are as follows:

1. Questions specific to the licensee's February 5, 2003, submittal 1.1 On Page 2 and on Page 5, the licensee identified participation by other than on-site personnel in such activities as detailed review of the installation and re-evaluation of the installation uncertainty calculations of the ultrasonic flow meters (UFMs). Please provide the basis for concluding, "that the equipment was performing within specification."

1.2 On Page 9, the licensee identified a MWe evaluation and toward the end of the letter, discussed other parameters associated with the plant secondary side. Please provide a description of observations and conclusions obtained during those or any other evaluations, including any items that may be consistent with a thermal power level being greater than 100 percent. Include any observations relative to the turbine/alternator performance, including but not limited to the overall conversion efficiency of the turbine generator with the assumption that the plant is operating at 100 percent thermal power.

2. Questions related to the feedwater flow meters 2.1 Included in topical reports Westinghouse has submitted affirming the accuracy of the AMAG CrossFlow ultrasonic flowmeter at a number of nuclear power plants, are comparisons of feedwater flow readings from the UFM with simultaneous readings from the installed venturi-based FW flow meters. Westinghouse notes that the FW venturis tend to defoul upon return to power following an outage, and that the UFM accuracy can, therefore, be confirmed immediately following start-up.

Please provide all available data showing simultaneous readings or correction factor computations for the venturis and the UFMs upon return to power or at other times when the venturis were known to be clean. Please provide the data, showing the degree of correlation between the two types of flowmeters. If such data do not exist, please provide the staff with information regarding how the data will be obtained. If simultaneous measurements are proposed, the venturi delta-P instruments should be calibrated before taking data, or supplemented with laboratory-grade devices. Please include uncertainty evaluations for the data measurement and acquisition equipment for both the existing data and new data.

2.2 Please provide a complete description of the methodology used to calculate the correction factors. Include the behavior as a function of power.

2.3 Fluctuations in the CF for Byron appear to be greater than at other plants. It was recommended by Westinghouse to run continuous UFM monitoring for a period of six months to possibly identify the root cause of the fluctuations. Please describe how the CF fluctuations at Byron compared with the CF fluctuations at Braidwood, and how indicated power is affected by the level of CF fluctuation. Describe actions that have been taken in response to the Westinghouse recommendation and what was found to be the root cause of this condition. Discuss the status of corrective actions to resolve this condition, and how the CF fluctuations currently compare between the Byron and Braidwood units.

3. Question related to the quality of the calorimetric calculations Provide information for Byron and Braidwood Stations regarding the methodology of the plants' calorimetric calculations, as well as calibration and uncertainty information for the instrumentation that is used as input to the calorimetric calculation. Include any changes in this information as a result of implementing the power uprate for the units and implementing the UFM for feedwater flow measurement.

4. Questions related to other secondary side equipment 4.1 Describe and explain any changes in the turbine efficiencies at Byron prior to and following UFM implementation. Provide the same type of information for Braidwood.

Also describe and explain any differences in turbine efficiencies between the Byron and Braidwood units prior to and following UFM implementation.

4.2 Describe and explain any differences in the turbine governor and throttle valves between the Byron and Braidwood units. Were these valves originally purchased as identical valves for Byron and Braidwood?

4.3 Were any modifications made to the turbine governor or throttle valves (or to the turbines) prior to, in conjunction with, or subsequent to power uprate?