Re: RADSAFE: static and alpha whole body monitors?

[Brian Rees <brees@lanl.gov>]

At our Pu facility PCMs (and others at LANL) we found that we need to keep
the detector screens dusted off (like every couple of days) to minimize Rn
progeny (dare not call them daughters!) buildup and subsequent background
increases.  You'd be able to confirm by seeing detectors 15, 16, 25 (?) -
detectors at hip level - typically most rubbed upon and therefore with most
dust- with the highest backgrounds first.  

If ALL your detectors show a high background you may be a victim of bad gas
- removing a single detector, purging it with a different source (lot,
supplier, date, etc) bottle, and putting it back in the PCM may lead you to
the solution.  Bad gas can take quite a while to recover from too. 

What are your setpoints and parameters?   We found that some adjustment was
needed when looking primarily for alphas.

Brian Rees
brees@lanl.gov 

At 01:08 PM 09/01/1999 -0500, you wrote:
>     People,
>     
>     We're still investigating our problem, here, but we think we're 
>     dealing with the following:
>     
>     A PCM-2 set up for alpha whole body counting is spending most of the 
>     day unable to operate due to "Background Too High" messages.
>     
>     We suspect this may be due to radon daughter plate-out on the 
>     counters.
>     
>     Has anyone had this experience and/or know of a potential solution for 
>     it?
>     
>     All regular and (viable) off-the-wall solutions welcome!
>     
>     Thank you!
>     
>     -David Levy
>     Fernald, Ohio
>     (513) 648-3816
>
>************************************************************************
>The RADSAFE Frequently Asked Questions list, archives and subscription
>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html