No Subject

["Reese, Robert P" <RPREESE@saix367.sandia.gov>]

     According to an application note I have from Canberra, it is Co-60 
     which contaminates post-WWII steel.  Apparently, the Co-60 was used 
     "in blast furnace crucible liners to monitor wear or breakthrough."  
     Canberra sells shielding material "batch tested" with "diminishingly 
     small Co-60 content."
     
     I always thought it was the nuclear-age fallout that laced post-WWII 
     steel.
     
        A correction: The low background steel talked about in the Canberra 
        application note is used in manufacturing cryostat vacuum chambers, 
        not shields.  
     
     
     
     ______________________________ Reply Separator 
     
     _________________________________ Subject: Re: shielding contaminants
     Author:  radsafe@romulus.ehs.uiuc.edu at CCSMTP Date:    11/10/95 5:10 
     PM
     
     
     Dear Dr. Low,
     
     I was always told to use pre-WWII battleship armor plate for low-level 
     shielding
     
     (there was no Cs-137 fallout contamination).  That was tens of years 
     ago, so I don't know if it is still available (It was sometimes 
     hoarded by the more "nuclear aware" scrap dealers, so you might still 
     be able to find some).