ML031270174

Request for Additional Information, RAI Required in Order to Fully Resolve Question of Licensed Power Limit from February 5, 2003 Response to Nrc'S Letter of January 22, 2003

ML031270174
Person / Time
Site:	Byron
Issue date:	07/08/2003
From:	Dick G NRC/NRR/DLPM/LPD3
To:	Skolds J Exelon Generation Co
Dick G F, NRR/DLPM, 415-3019
References
TAC MB7378
Download: ML031270174 (7)

Text

July 8, 2003 Mr. John L. Skolds, President Exelon Nuclear Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

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 NRCs 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,

/RA/

George F. Dick, Jr., Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. STN 50-454

Enclosure:

As stated cc w/encl: See next page

July 8, 2003 Mr. John L. Skolds, President Exelon Nuclear Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

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 NRCs 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,

/RA/

George F. Dick, Jr., Project Manager, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. STN 50-454

Enclosure:

As stated cc w/encl: See next page Distribution:

PUBLIC PDIII/2 r/f L. Marsh A. Mendiola P. Coates M. Chawla G. Dick OGC, O15B18 ACRS, T2E26 G. Grant, RIII A. Stone, RIII P. Loughheed, RIII D. Hills, RIII W. Lyon P. Rebstock J. Tatum G. Cranston ADAMS Accession Number: ML031270174 *see previous concurrence OFFICE PM:PD3-2 LA:PD3-2 SC:SPLB SC:EEIB SC:SRX SC:PD3-2 B

NAME GDick PCoates DSolorio* AMarinos JUhle LRaghavan for AMendiola DATE 07/01/03 07/01/03 07/04/03 07/01/03 07/02/03 07/08/03 OFFICIAL RECORD COPY

Byron Station Units 1 and 2 cc:

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

Byron Station Units 1 and 2 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 licensees response of February 5, 2003, to the NRCs 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 staffs questions or information needs are as follows:

1. Questions specific to the licensees 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?