Re: Smearing sources

[Keith Welch <welch@CEBAF.GOV>]

You wrote: 

 A Instrument Cal tech at my facility is trying to find information on a
    > practice we perform with our sources.  Every year we do a yearly leak 
    > check using a wet smear and a dry smear. We want to drop the wet 
    > smear..we are just not sure why we were doing it. Is there anything in 
    > the regs that require it? Any help you can provide would be appreciated.
   
 Wet, dry, and imersion tests are all appropriate depending on the
situation.  For most situations dry swipes are acceptable, the basis being
the dry swipe represents 'real world' transferable activity. I agree that
the best advice is "check your license".  I think the wet smear practice
came into use because of the infrequency of source leak checks and the
desire to maximize sensitivity, especially when dealing with encapsulated or
inaccessible sources.  Also, as was mentioned, some of the methods are
directed at manufacturers, not the end users.

My question is this - I thought the regs required a semi-annual test, not
annual.  What is your governing regulation?  
Keith Welch
Thomas Jefferson National Accelerator Facility
Newport News VA
welch@cebaf.gov