[ RadSafe ] Survey MDAs vs. Scan MDAs

[Ron Reif]

Dear Radsafe list:

 

I'm trying to determine the Minimum Detectable Activity (MDA) for gross
alpha measurements using a GM detector coupled to a rate meter.  Some
colleagues have pointed me to NUREG-1757, which I have reviewed.  NUREG-1757
refers to NUREG-1507, "Minimum Detectable Concentrations with Typical
Radiation Survey Instruments for Various Contaminants and Field Conditions",
June 1998.  However, I cannot locate this document on NRC's web site.
Apparently, they do not keep 'older' documents on their web site.  Does
anyone have the proper MDA equations for evaluating (a priori) the
sensitivity of a rate meter?  It is my understanding that the standard MDA
equation for integrated measurements (scaler mode) does not apply to rate
meters.  A link to NUREG-1507 would also be appreciated.  

 

Please reply directly to me.  Thank you.

 

 

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Ron Reif, P.E.,CHP,CIH

EH&S Manager

Woods Hole Oceanographic Institution

http://ehs.whoi.edu

p:508-289-3788

f:508-457-2015