Re: ???Selection of MDA for Volumetric Contamination

["ERIC GOLDIN" <goldinem@songs.sce.com>]

     Jim,  For nuclear plants, the definition of "how hard you have to 
     look" is clearly specified in the Radiological Effluent Technical 
     Specifications in the Offsite Dose Calculation Manual, (see 
     Environmental Sample Analysis Table 4.12-1 in NUREG-1301 or 
     -1302, or the older versions NUREG-0472 or -0473).  The LLD of 
     the system (determined 'a priori') is defined for specified 
     isotopes in different media: water, airborne particulates, fish, 
     milk, food products and sediment.  You then simply analyze the 
     material sufficiently long to ensure you meet the required 
     sensitivity for the specified isotopes.  This is all based on the 
     concept that anything detectable means no release for 
     unrestricted use, absent the provisions of liquid effluents, 
     sewage disposal, etc.  Let me know if you'd like me to fax you a 
     few pertinent pages, or the memo from the NRC that says this is 
     how "free" releases are done (HP Position Paper #221 in 
     NUREG/CR-5569).
     
     Some selected LLDs are:  For sediment - 150 pCi/kg Cs-134; 180 
     pCi/kg Cs-137
     For water - 2000 pCi/l H-3, 15 pCi/l Co-60, 18 pCi/l Cs-137....
     For fish...
     
     Eric Goldin
     Southern California Edison
     goldinem@songs.sce.com
     Disclaimed, of course