[ RadSafe ] Internal Dosimetry and FGR 11

[alstonchris at netscape.net]

Darren

Yes, you are absolutely correct.? That's why references like NUREG/CR-4884 give you the Intake Retention Fractions (IRF's) at specified times post-intake; so that you can back-calculate from your estimate of "body-burden," to an estimate of how much the original intake would have been.


Cheers
cja


-----Original Message-----
From: Perrero, Daren <Daren.Perrero at illinois.gov>
To: radsafe at radlab.nl
Sent: Fri, 30 Jan 2009 6:17 pm
Subject: [ RadSafe ] Internal Dosimetry and FGR 11



Can someone out there help clarify an issue for me and reinforce my
notion that there's no such thing as a dumb question?  

FGR 11 is based on modeling from ICRP 30.  In specific Tables 2.1 and
2.2 in that document provides estimates of committed dose equivalents
for INTAKES (my emphasis added) of various radionuclides.  The term
INTAKE in this context does NOT mean the amount of material measured
in-vivo in an organ such as the breast, lung, or thyroid.   The in-vivo
measurement, or UPTAKE, needs to be converted to INTAKE in order to
apply the values found in FGR 11.  Intakes can be estimated by using a
reference such as NUREG/CR-4884 if the interval between the date of the
event and the measurement is known.  

Is my understanding correct or am I making this harder than it needs to
be?

Daren Perrero
The opinions expressed are mine, all mine....
I'm with the government, I'm here to help you.
Daren.Perrero(a)Illinois.gov