Re: use of neutron sources

["Wesley M. Dunn" <WDUNN@brc1.tdh.state.tx.us>]

Bill,

It is most like a "roof moisture gauge", which typically contain 
40-50 mCi of Am-241(Be).  Neutrons bounce off water, so this device 
is pretty effective.  Road crews use similar devices for density 
(using 10 mCi of Cs-137) and moisture measurements.

Obviously, the neutron and gamma doses are pretty low (except when 
your badge is clipped to your jacket that is lying on top of the 
gauge for awhile).  Usual security is visual (e.g., direct 
supervision or under lock and key).  They are normally stored in 
their transport container when not in use.  This is usually a license 
committment by the compnay.

Hope this helps,

Wes

> Date sent:      Wed, 5 Feb 97 06:55:55 -0600
> Send reply to:  radsafe@romulus.ehs.uiuc.edu
> From:           LIPTONW@detroitedison.com
> To:             Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Subject:        use of neutron sources

> 
> I received a note from our maintenance group that roofers will be bringing a 
> neutron source on site.  I have no idea what this is for! 
>  
> I'd appreciate information from anyone who is familiar with this use of a 
> neutron source regarding: 
>  
> what kind of source 
>  
> expected activity level 
>  
> purpose 
>  
> special precautions 
>  
> Please reply thru RADSAFE or directly to me. 
>  
> Bill Lipton 
> liptonw@detroitedison.com 
>  
> 
> 
> 
*********************************************************************
Wesley M. Dunn, CHP                        512-834-6688
Deputy Director, Licensing                 512-834-6690 (fax)
(Texas) Bureau of Radiation Control        wdunn@brc1.tdh.state.tx.us
*********************************************************************