Beta measurements at Nuclear Power Plants

["James P. Tarzia" <tarzijp@naesco.com>]

     Fellow Radsafers, 
     
     This is a question for Nuclear Power HPs:
     
     Discussion:
     
     Beta dose rate measurements using ion chambers (i.e. RO2, RSO5 type 
     split chamber instruments) are typically performed by subtracting 
     closed window(CW) from open window(OW) readings and then multiplying 
     the value by some beta skin dose conversion factor(CF) (CFs usually 
     range from 2 to 4). This method is applicable when assessing skin dose 
     but can be misleading when trying to assess removable contamination 
     levels on smears or on equipment in units of dpm unless the beta skin 
     dose CF is factored into the contamination CF. CFs used for 
     calculating dpm from ion chamber measurements on smears are usually 
     based on just the open window minus closed window measurement.
     
     I am trying to determine what other power plants require of their HP 
     technicians when documenting contamination surveys.  Contract 
     technicians get confused because they appear to be required to report 
     these values differently from one plant to another.
     
     Questions:
     
     Is the (OW-CW)*CF method used when documenting the results of smears 
     measured with an ion chamber or is just the (OW-CW) value reported.
     
     What CF is used for determining Beta Skin Dose Rate and what 
     conversion factor is used to convert ion chamber contamination 
     readings in mR/hr to dpm.  
     
     How are your CFs determined (i.e. what mix, nuclides, sources 
     geometry,etc.)
     
     Thank you in advance for your response:
     
     
     Jay Tarzia
     tarzijp@NAESCO.com
     603-474-9521 Ext. 3868