ML080280123
| ML080280123 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 01/24/2003 |
| From: | Exelon Nuclear |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2008-0046 | |
| Download: ML080280123 (7) | |
Text
Nuclear Byron Thermal Power Measurement Exelon Presentation to Nuclear Regulatory Commission January 24, 2003 1
Nuclear Ultrasonic Feedwater Flow Measurement Overview
- Ultrasonic feedwater flow instruments evaluated for use at Braidwood and Byron Stations in 1998
- Ultrasonic measurement of feedwater flow selected for Braidwood and Byron Stations in 1999
- Initial testing conducted in late 1998, early 1999
- Ultrasonic feedwater flow instruments implemented at Braidwood in June 1999
- Ultrasonic feedwater flow instruments implemented at Byron Station in May 2000 2
Nuclear Byron* Station Ultrasonic Flow Measurement Evaluation
- In May and June 1999 Braidwood and Byron used ultrasonic flow instruments to determine feedwater flow venturi correction factors Byron Station - approximate 2% correction factor Braidwood Station - approximate 1% correction factor using identical techniques
- Byron Station reviewed results and secondary plant parameters, with Corporate support Issues associated with secondary plant parameters and Braidwood/Byron correction factor difference needed further evaluation 3
I ~SM Nuclear Byron Station Ultrasonic Flow Instrument Validation June 1999-May 2000
- Dual instrument test at Byron with ultrasonic flow instruments
- Additional validation testing at Braidwood to compare data acquisition
- Ultrasonic flow instrument vendor (AMAG) review of Byron installation
- Industry benchmarking comparison of correction factors L/
- Industry +/-3%, average - 1.7%
- Independent testing of AMAG technology at Alden Labs
- Internal Exelon Design Engineering review
- Review of secondary plant parameters, fuel utilization and heat rates
- Implementation procedures
- Byron implementation of ultrasonic flow instruments in May 2000
- Correction factors of 1.7% (Unit 1) and 1.6% (Unit 2) 4
Nuclear Power Uprate Implementation
- 5% Power Uprate on Byron Units 1 & 2 in May 2001
- Design utilized 1998 calorimetric data
- Units 1 and 2 power increases not fully achieved
- 5% Power Uprate on Braidwood Unit 1 in Oct 2001
- Expected power level achieved
- Difference in power level achieved between Braidwood and Byron Units 1 captured in Corrective Action Program
- 5% Power Uprate on Braidwood Unit 2-in April 2002
- Expected power level achieved 5
Nuclear Review of Correction Factor Differences
" Exelon Independent Review in February 2002 concluded additional detailed evaluation needed
- Correction 'factor reset to 0% as result of review
" Additional review of core bum-up and fuel depletion
- Evaluated by Corporate Nuclear Fuel Management and Westinghouse
- Correction factors reinstalled following results of the evaluation
" Thorough review of Byron ultrasonic flow measurement implementation
- Electronics, dimensions, installation, data gathering, redundant flow meter, procedures, calorimetric
- Concluded ultrasonic instruments measured flow per design and implemented properly 6
C'1*
Ex÷ nsm Nuclear Byron Apparent Cause Evaluation
- Apparent Cause Evaluation (ACE) completed in Oct 2002
- Apparent cause of the unit differences indeterminate
- Byron Station evaluated issue in aggregate
- Acknowledged dissenting view of ACE evaluator
- Byron Station concluded ultrasonic feedwater flow measurement instrumentation is within expected tolerance
- Based on multiple validation reviews by vendor and Corporate Exelon expert
" Exelon Nuclear Fuel Management review concluded Byron core bum-up was within expected uncertainty analysis
" ACE concluded Byron was operating within licensed power limits
° Corrective actions require ongoing monitoring and trending of ultrasonic feedwater flow measurement~7