RE: Personal Alpha CAM (PCAM)

["Goff, Tom" <tom.goff@rfets.gov>]

Ron

I will also be at the Orlando meeting.  Perhaps we could get together and
discuss this unit.

The reception is Sunday night and I plan on being there.

Our project is really interested in obtaining a device like you describe.

Tom Goff


> -----Original Message-----
> From:	Ron Morgan [SMTP:rgmorgan%lanl.gov@inet.rfets.gov]
> Sent:	Monday, January 25, 1999 6:21 PM
> To:	Multiple recipients of list
> Subject:	Personal Alpha CAM (PCAM)
> 
> 
> I am the co-inventor of a lapel-mounted alpha CAM called the PCAM, with a
> battery/electronics pack worn on the belt.  It is currently in the
> integration/beta-testing phase of development.  We invented it because of
> problems with fixed CAMs that we (the inventors) felt we could overcome.
> Consider, for example, the huge sample dilution rates that usually
> accompany the use of a fixed CAM (normally a factor of 100 to 1000), and
> the expensive (and usually not-well-done) airflow characterization studies
> that are required.  A lapel-mounted CAM does not have the high sample
> rates
> that a fixed unit enjoys, but the fact that the breathing zone is always
> being sampled may (emphasis on may) provide a net benefit.  Radon IS a
> problem with a lapel sampler if an MCA cannot be utilized (we're working
> on
> it), but how much radon would you expect in an air hood?  Also, dust
> buildup should not be as large a factor in lapel sampling as it is in
> fixed
> CAM sampling (lower flow rates, shorter run times).  We feel we may
> (emphasis on may) be able to effectively compete with fix CAMs, given that
> the project runs as we expect it will (i.e. we don't run into any
> technical
> or financial brick walls).
> 
> On 25 Jan 99 10:21:36 Bill Lipton wrote:
> Please consider: 
>  
> 1.  How's someone going to carry the detector and electronics, eg., a 
> photomultiplier tube!, on his lapel? 
>  
> 2.  Even if you could, how would you separate the TRU from the Rn
> daughters?
>  
> For example, assume that the airborne concentration of Pu-239 is 100 DAC =
> 3 
> E-10 uCi/ml.  Assume that the cam is operating at the reference man
> breathing 
> rate of 20 liters/min.  Then, the cam would sample 9.6 E6 ml in an 8 hour 
> shift, and, assuming 100% filter collection efficiency, the total activity
> 
> sampled would be less than 3 nCi.  I doubt that this can be detected by 
> available instrumentation without letting the background decay.  Dust
> buildup 
> on the filter would degrade both the detector efficiency and the alpha 
> spectrum, so I doubt that, even with spectroscopy, the TRU alphas could be
> 
> separated out in real time.    
>  
> 3.  Why do you feel the need to provide alpha cam's?  Your radiological 
> controls should be good enough to prevent sudden changes in airborne
> levels 
> during routine operations.  For those nonroutine operations, such as
> system 
> breaches, where there is a likelihood of a release, the workers should be 
> wearing adequate respiratory protection. 
>  
> The opinions expressed are strictly mine. 
> It's not about dose, it's about trust. 
>  
> Bill Lipton 
> liptonw@dteenergy.com 
>  
> You wrote: 
>  
> >Does anyone know of a lapel type/size alpha continuous air monitor.  This
> 
> >device would provide a continuous indication of alpha airborne
> radioactivity 
> >to the wearer. 
>  
> >Please respond to: 
>  
> >Tom Goff 
> >Rad Engineering 
> >Rocky Flats ETS 
> >Tom.Goff@RFETS.gov 
> 
> *********************************************
>    Ron Morgan
>    Radiation Protection Services (ESH-12)
>    Los Alamos National Laboratory, MS K-483
>    Los Alamos, New Mexico, 87544 (USA)
>    Phone (505) 665-7843
>    FAX   (505) 667-9726
>    Mailto:rgmorgan@lanl.gov
> *********************************************
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