Sonic vs. Cup/Vane Data Comparison at the Cooper Nuclear Station Jim Holian SAIC Jim Holian SAIC NUMUG Meeting St. Louis, MO October 2006 NUMUG Meeting St. Louis, MO October 2006

CNS Meteorological System Upgraded 100-meter tower in 2004 to include a dual elevator on the same tower face Dual monitoring systems with independence from sensor to Plant Computer Wind Sensors have Cups/Vanes on one side and Sonic on the other

Systems A and B  10, 60, and 100 meter wind speed and direction  3 Delta-ts (60m-10m, 100m-10m, 100m-60m)  10, 60, and 100 meter temperatures System A only  10 meter dew point  Station Pressure  Precipitation Meteorological Parameters

System A  Climatronics F460 Wind speed and Direction Sensors  Climatronics Temperature Sensors  Tower Systems Elevator  Climatronics Dew Point Sensor  Climatronics Tipping Bucket Rain gauge with Wind Shield  Campbell Scientific 23X Micro Dataloggers  Climatronics Pressure Sensor Meteorological Equipment

System B  Met One 50.5 Sonic Wind speed and Direction Sensors  Climatronics Temperature Sensors  Tower Systems Elevator  Campbell Scientific 23X Micro Dataloggers Meteorological Equipment

Purpose Independently verify wind data collected from both systems are not statistically different Data from System A (cup/vane) can be interchanged with data from System B (sonic) Demonstrate the impact of the tower structure on meteorological data

Data Set One year of onsite validated hourly meteorological data (October 31, 2004 – October 30, 2005) 8784 possible hourly values for each parameter for both Systems A and B on the 100-meter tower

Methodology Remove bad data from System A and System B files including calibrations, frozen sensors, failed sensors, bad data spikes, etc Remove wind directions when wind speeds less than 3 mph and/or wind directions are through tower Remove wind speeds when wind directions are through tower

Table 3–1 Invalid Data for CNS Onsite Meteorological Program October 31, 2004 – October 30, 2005 ParameterMissing/Bad DataHoursProblem All Parameters (A&B)3/ – 4/ / – 4/ Spring Calibration All Parameters (A System Only) 8/ – 8/ Troubleshoot – All 3 levels down All Parameters (A&B)9/ – 09/ Fall Calibration 100 Meter Wind Speed(A) 1/ – 1/ / – 2/ (B) 1/ – Frozen Sensor Bad Data-Spike 60 Meter Wind Speed(A)1/ – 1/9/ / – 8/ / – 10/ (B) 1/ – Frozen Sensor/Sensor Failure Bad Data-Spike 10 Meter Wind Speed(A)1/ – 1/ Frozen Sensor 100 Meter Wind Direction (B) 1/ – 16009Bad Data-Spike 60 Meter Wind Direction (B) 1/ – 21003Bad Data-Spike

Wind Directions from degrees blow through tower Window is 25 degrees for vane and cup sensors and 30 degrees for sonic sensor

Data Availability 100- meter wind speed82% 60-meter wind speed87% 10-meter wind speed88% 100-meter wind direction84% 60-meter wind direction45% 10-meter wind direction70%

Results Unobstructed with no tower influence

Wind Speed Averages HoursA Avg.B Avg.Diff.Abs. 100-M WS M WS M WS

Wind Speed Correlation HoursDiff.SlopeY-int.Corr. 100-M WS M WS M WS

Wind Direction Averages HoursA Avg.B Avg.Diff.Abs. 100-M WD M WD M WD

Wind Direction Correlation HoursDiff.SlopeY-int.Corr. 100-M WD M WD M WD

Tower Impacts Wind Speed and Direction

Wind Directions from degrees blow through tower Window is 25 degrees for vane and cup sensors and 30 degrees for sonic sensor

100-m Wind Speed Averages Tower Impact HoursA Avg.B Avg.Diff.Abs. 100-M WS-A M WS-B

100-m Wind Speed Correlation Tower Impact HoursDiff.SlopeY-int.Corr. 100-M WS-A M WS-B

60-m Wind Speed Averages Tower Impact HoursA Avg.B Avg.Diff.Abs. 60-M WS-A M WS-B

60-m Wind Speed Correlation Tower Impact HoursDiff.SlopeY-int.Corr. 60-M WS-A M WS-B

10-m Wind Speed Averages Tower Impact HoursA Avg.B Avg.Diff.Abs. 10-M WS-A M WS-B

10-m Wind Speed Correlation Tower Impact HoursDiff.SlopeY-int.Corr. 10-M WS-A M WS-B

100-m Wind Direction Averages Tower Impact HoursA Avg.B Avg.Diff.Abs. 100-M WD-A M WD-B

100-m Wind Direction Correlation Tower Impact HoursDiff.SlopeY-int.Corr. 100-M WD-A M WD-B

10-m Wind Direction Averages Tower Impact HoursA Avg.B Avg.Diff.Abs. 10-M WD-A M WD-B

10-m Wind Direction Correlation Tower Impact HoursDiff.SlopeY-int.Corr. 10-M WD-A M WD-B

Conclusions Outside of Tower wake impacts, Systems A and B are statistically the same for WS/WD. Outside of Tower wake impacts, all differences are small. WD small bias likely due to alignment errors during calibration.

Conclusions (cont’d) Cup anemometer records wind speed on average 1mph higher than sonic – likely due to overspeeding. Tower wake has greatest impact on wind speed. Differences up to 10 mph seen at wind speeds above 25 mph. Appears the wind speed tower impact is largest on sonic sensors – but is it? Data from either system are interchangeable

Conclusions (cont’d) Tower wake has little to no impact on wind direction on either vane or sonic sensors. Data from either System A (cups/vanes) or System B (sonic) are interchangeable outside of tower wake. Within wake, data scrutiny is needed either manually or with software.