[ RadSafe ] Ag-108m

[Dustin G. Miller]

Not to be overly defensive or rude to anyone, but my colleagues and I are
intimately familiar with the ResRad family of codes and establishing release
criteria.  The ResRad code would provide better results, but my interest
lies in being able to calculate a "screening value" for Ag-108m the same way
the NRC and its contractor did for the screening values listed in
NUREG-1757, Part 2, Appendix H.  This would be the easiest route to
obtaining a DCGL for remediation purposes because I would only have to
explain that the site's parameters are more conservative than the default
values used in the D&D codes.  Once I switch over to the ResRad code for
DCGLs, there is a lot more time and effort to run the probabilistic site
specific scenarios...and the subsequent discussions with the regulators.  

And, yes, Ag-108m is a primary contaminate.

Thanks everyone for your comments, but I already knew the Ag-108m basics
from the chart of the nuclides, the rad health handbook, and several other
sources.

Respectfully,

Dustin Miller
Health Physicist

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of
rdecker2 at ix.netcom.com
Sent: Wednesday, June 08, 2011 12:55 AM
To: radsafe at agni.phys.iit.edu
Subject: [ RadSafe ] Ag-108m

I'm not sure why one would wish to use DandD for determining DCGL's.  I
would think using RESRAD codes would provide a better results. I don't
remember if Ag-108m is a part of their library (and I don't have it loaded
on this computer) however you may be able to use Ag-110 if you could provide
evidence that it is s more conservative value (based perhaps on critical
organ using teens or children).

You may also "argue" the scenario with the regulator as to whether the use
of children or teens is a "reasonable" condition of the scenario (after
clean up the site is still controlled by the same owner and teens and
children are not allowed on the site).  

Also, if the contribution of Ag-108m is a very small fraction of the nuclide
mixture its contribution will likely also be low.  You could run a decay of
the other nuclides over time and note the residual activity (dose)as the
shorter lived radionuclides decay off (using Ag-110 to bogus Ag-108m at a
T-1/2 of 127 or ~436 years (whichever reference you use for T-1/2). You may
find the dose contribution of this nuclide (Ag-108m) to your nuclide mix is
bug dust (but you would still have to account for it).

Give the people at Argonne East a call: Charlie Yu or one of the people in
his group and talk to them about Ag-108m and your concern.  You can get
their numbers from the RESRAD Codes site they may be able to provide you
with insight as to why DandD does not include Ag-108m.
_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu