RE: DCFs

["Jeri L. Anderson" <janderson@mjwcorp.com>]

The DCFs in FGR 11 are based on a 1 um AMAD aerosol.  Perhaps, the DOE
numbers are based on a different particle size.  The CINDY code gives
4.8E+08 rem/Ci for 5 um and 5.0E+08 for 10 um.

***********************************************
Jeri L. Anderson, Ph.D.
Sr. Internal Dosimetrist/Consulting Health Physicist
MJW Corporation
338 Harris Hill Road, Suite 208
Williamsville, NY  14221
Phone (716) 631-8291
Fax (716) 631-5631
E-Mail: janderson@mjwcorp.com
http://www.mjwcorp.com
***********************************************

> -----Original Message-----
> From: radsafe@romulus.ehs.uiuc.edu
> [mailto:radsafe@romulus.ehs.uiuc.edu]On Behalf Of Michael Stabin
> Sent: Friday, February 25, 2000 1:03 PM
> To: Multiple recipients of list
> Subject: DCFs
>
>
> >
> > I did a quick run on the CINDY code and got a result of 4.4 E8 rem/curie
> for the
> > inhalation of Class-W Pu-239.  It looks like FGR 11 and the CINDY code
> pretty
> > much agree on this one.  I do not know the source or accuracy of the
> DOE/EH-0071
> > values.
>
> I'm also not familiar with the DOE values.  However, Dr. Kearfott of
> Michigan participated in a study a few years back that showed that DCFs
> between ICRP 30, 10CFR20 and the FGR can vary quite a bit, owing mostly to
> roundoff errors in jumping between Ci and Bq units, with DCF values using
> only using 1 or 2 sig figs.  DACs and ALIs also may not be consistent with
> each other.  Even the original ICRP 30 numbers suffer a bit in this
> roundoff - for example, I estimate that the real ALI for ingestion of P-32
> should be 2.4E7 Bq, which comes out in ICRP 30 itself as 2E7 Bq
> (rounded to
> 1 sig fig).  The FGR and 10CFR 20 then have the value as 600 uCi.
>
> This can of course become problematic when you have a situation
> (like at the
> NIH and at MIT in recent memory) where you have an intake close
> to the ALI,
> and you are playing the "bright red line" game with the NRC.  First,
> everyone knows that the calculated values of intake and dose have big
> uncertainties, and that your estimate of intake based on one or more
> bioassays has a big uncertainty.  But if the reg is 600 uCi and
> intake comes
> up as 610 uCi (actually 601 will do), you are over the line. If the line
> itself has this much uncertainty because of rounding errors (570? 600?
> 650?), it would seem unfair to me that one would have to pay a
> fine in this
> circumstance.
>
>
>
> Michael Stabin, PhD, CHP
> Departamento de Energia Nuclear/UFPE
> Av. Prof. Luiz Freire, 1000 - Cidade Universitaria
> CEP 50740 - 540
> Recife - PE
> Brazil
> Phone 55-81-271-8251 or 8252 or 8253
> Fax  55-81-271-8250
> E-mail stabin@npd.ufpe.br
>
> "Quantum Mechanics: The dreams stuff is made of"
> - Steven Wright
>
>
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