[ RadSafe ] The Burger That Shattered Her Life

[Eric Goldin]

Hi Barbara, long time no see.   I'm always a bit behind (get the digest version of Radsafe) and am away from my office, but I vaguely recall the "divide by 2" is the means to get to critical level.  In other words, Lc = 0.5 x LLD where LLD is the a priori determination of detection capability.  If the actual counts were less than Lc, we say the radionuclide was not detected, if the counts were above Lc, regardless of whether they exceed LLD, we say the radionuclide was detected.  Therefore, for environmental level measurements of samples, in many cases, we'll report radionuclides as detected even though less than the LLD.  But then again, I don't have access to any of the papers I have to normally refer to, so this may all be wrong.  

Eric Goldin, CHP
<emgoldin at yahoo.com