Re: Labware grinder

[JDillon@mercury.ligand.com]

Bob,

You can simply take a swipe of the labware using filter paper, since you should 
be concerned about removable contamination.  If the labware itself is 
contaminated it will have to be disposed of as rad waste, but that should not be 
the case.  If contamainated you should be able to decontaminate the labware so 
that it can be disposed of as normal waste.  If your labware has a configuration 
where that you can not swipe the internal surfaces you may want to first "wash" 
the interior with a decontaminate such as Radiac and collect that wash, sample, 
and then release (provided your license allows sewer release, and make sure to 
complete the release calculations).  Then you can collect a representative (eg. 
1 ml) wash sample from the labware and count in your scintillation counter to 
determine if there is any additional removeable contamination prior to releasing 
as non-rad.  Repeat the process if you still find contamination.

Jon Dillon
jdillon@ligand.com

_______________________________________________________________________________
Subject: Labware grinder
From:    radsafe@romulus.ehs.uiuc.edu at Gateway
Date:    4/5/95  2:07 PM

        Our Biology Department has been using disposable labware for 
        procedures using small quantities of 3H. The 3H is within limits 
        of sewer disposal, so the PI was washing the labware to dispose 
        of as common trash. Enter NRC inspector who quoth "nevermore", 
        since the procedure was not in our license. Then came the 
        license renewal with a request to allow us to "wash slightly 
        contaminated disposable labware, and if determined to be free of 
        contamination following washing (net count less than 3X standard 
        deviation above the background count for the liquid 
        scintillation counting system), to dispose of such items as 
        non-radioactive waste. This authorization will be restricted to 
        beta emitting radionuclides, primarily H-3.". Then came approval 
        of the request. ALL OF THIS BEFORE I RECENTLY BECAME RSO. 
        (Sorry, but the shouting seemed necessary.)
        
        Now to the question, does anybody have an idea how to pull this 
        off? In order to comply, I have to get a count off of the 
        labware. This implies that I either have a _very_big_ liquid 
        scintillation counter (and I don't), or I have to reduce the 
        labware to _very_little_ pieces to get a sample into the counter 
        that I have. This would suggest a grinder/chopper of some kind 
        but I have never seen one marketed for this purpose, or for that 
        matter, for any purpose.
        
        Does anyone have an idea?
        
        "New-boy-on-the-block"
        Bob Jacobs, RSO
        University of St. Thomas
        2115 Summit Ave, Mail #PHP
        St. Paul, MN  55105
        
        Tel (612)962-6530
        Fax (612)962-6540
        E-Mail rhjacobs@stthomas.edu