[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: Dirty bombs
This is really an issue of "How clean is clean enough". When
decommissioning a licensed facility we are required to take more effort to
chase "the last atom" because of the exposure scenarios that are associated
with the development of cleanup criteria. Such decommissioning scenarios
should not be considered applicable to the cleanup associated with an act of
terrorism particularly in an outdoor environment. It seems to me that one
of the considerations that should be thought out now is what would be the
appropriate cleanup criteria to be applied in the event of such an act of
terrorism. Otherwise we are going to end up with the default criteria. The
elements that would be required to establish appropriate criteria might be
as follows:
* Establish a rational dose criteria to be used in these scenarios.
This might be done on a time dependent basis such as the first five years,
the second 10 years, etc.
* Define a realistic scenario for the dose calculation based on
different dirty bomb scenarios.
* Establish a model that is based on realistic model parameters, not
using the general approach for decommissioning models where the parameters
are the 90th percentile or other levels of conservatism.
* Use the above to establish reasonably protective cleanup criteria
that can be used in such an event before the act rather than trying to
develop the criteria in the "heat of the moment".
Just my humble opinion
A. Joseph Nardi, Supervisory Engineer
Westinghouse Electric Company
P. O. Box 355
Pittsburgh, PA 15230
Telephone: 412-374-4652
FAX Number: 412-374-3357
email: nardiaj@westinghouse.com
John Andrews wrote:
> I cleaned up an old spill of Cs-137 once. The material had been cleaned
> up years earlier, but residual material remained on some of the
> concrete. It had penetrated into the concrete up to one inch in
> discrete spots. This indicated to me that actual grains of the spilled
> source material remained on the concrete and the cesium was sorbed by
> whatever reaction into the concrete. There was low level general
> contamination just above backround in adjacent areas indicating
> migration from the hot spots. Effective cleaning included jackhammering
> or intense needle-gun decon of the spots and scabbling the general areas
> to 1/2 inch.
>
> I would expect the same from any Cs-137 spill.
>
> John Andrews
> Knoxville, Tennessee
>
> ************************************************************************
> You are currently subscribed to the Radsafe mailing list. To unsubscribe,
> send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
> radsafe" (no quote marks) in the body of the e-mail, with no subject line.
> You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/
>
>
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.
You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/