Re: Dirty bomb predictions

[AndrewsJP@AOL.COM]

In a message dated 3/7/02 11:34:19 AM Pacific Standard Time, blc+@PITT.EDU writes:



>     The cesium would be mostly washed away by the first rain, going
>
> down sewers. A little work with hoses along with radiation detection
>
> meters would be even more efficient. On soil, as in parks, it could be
>
> covered with dirt, but that would be a very small part of the exposure.
>
>
> Bernard L. Cohen



Maybe, maybe not.  The one I cleaned up after was a spill of the material to be placed into a sealed source.  It got blown around by the air conditioning and thourouly contaminated the building containing the operation.  Years later, when I got involved, some of the Cs-137 was deeply imbeded in the concrete where the grains of CsCl(?) were overlooked.  Decontamination required drilling or coring to remove the spots.  All in all, there was no risk to the occasional occupants. The material was really fixed in place. I guess the issue with sealed sources in dirty bombs is that the material will be dispersed in the existing form and not necessarily pulverized into breathable sized fractions.  A typical Cs-137 Hastalloy C single encapsulated source may even survive the explosion.  The same is true for bare cobalt rods.  The hype on NPR this morning started out OK, then went downhill from there.


John Andrews

Knoxville, Tennessee