A Dual Elevator Meteorological System at the

Cooper Nuclear Station

Jim Holian/Russ SoutherlandSAIC

June 2005 NUMUG Meeting

• 1982 design • Single sensors on 100-meter tower - WS,

WD, T, Delta-T (10-, 60-, and 100-meter)• Single elevator system• 10-meter backup tower• Precipitation on shelter roof• PDP 11/34 computer system (in Plant)

Existing Meteorological System (9/04)

• Difficulty achieving 90% data recovery• I&C delay repairing system• Increased sensor/wiring failures• Single point of failure – PDP 11/23• No viable independent backup system• Lost data during power failures• System becoming labor intensive ($$$$)

Problems

Old Single Carriage

• A viable, independent backup system with independent elevator system, allowing one system to be taken out of service without impacting the other.

• Averaging performed in the MET shelter

• Primary and secondary storage of digital data in the MET shelter as well as on PMIS.             

CNS Met Upgrade Requirements

• Off-the-shelf commercial-grade equipment with the averaging software included within the unit, eliminating the need to develop and maintain software and associated quality control on the PMIS.

• Real-time meteorological data validation based on meteorological principles, CNS site conditions, and climatology

• Eliminate strip chart recorders            

CNS Met Upgrade Requirements

• Automatic and immediate substitution of data whether a single sensor fails, is impacted by meteorological conditions, or the entire System A or B is out of service.

• Real-time meteorological data validation based on meteorological principles, CNS site conditions, and climatology

• UPS system in place to maintain power to the MET instruments during short-term station blackout             

CNS Met Upgrade Requirements

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 DataloggersClimatronics 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

• Two Elevator Systems on same face (biggest design challenge)

• Validation without elimination

• Reduce false 9 out of data

• Include onsite conditions/climatology

Dual System Design Basis

•Produce a valid data set that is the “best of”

•Reduce manual labor

•Decrease maintenance costs (i.e. Sonic)

•Independently shut down individual sensors

Dual System Design Basis (cont’d)

• Detects the presence of wind direction shear between tower levels

• Identifies differences in the data attributable to tower interference

• Recognizes light and variable winds

• Identifies wind speed cup/threshold problems before they become obvious

Site-Specific Software

Site-Specific Software (cont’d)

•Recognizes delta-t differences attributed to sunrise/sunset/precipitation onset

• Identifies aspirator trips/fluctuations

• Identifies problems associated with temperature/dew point/precipitation interactions

•Ability to turn off any sensor remotely

Tower Interference

0-3 Good data, best of both Systems A and B

4-6 Requires closer review because system validation was limited or non-existent

 7-8 Requires intense scrutiny because data failed

system validation

9 Bad or missing data

Validity Flags Summary

Construction/InstallationBrownville, Nebraska

(Sept-Oct 04)

Wind, wind, and more wind!!!

Old Winch Box

Old Elevator Box

Old Rack

Dual Monitoring System

Met Shelter Onsite

• Dual elevator installed on same tower face• Totally independent dual meteorological monitoring system • System operational since 10/26/04• No problems to date – system performing as designed.• Automatic data validation – (interesting comparisons between standard/sonic sensors – future NUMUG paper!)

CNS Dual System Summary