NextRight led me to this, about another potential source of radioactive material for "dirty bombs".
My background is not in health physics, but having spent a fair amount of time in nuclear power plants I know a little. Cesium (Cs) and strontium (Sr) are bad news because they have a particular affinity for the human body, giving high doses to areas that are particularly susceptible to them.
However, there's only so much there. It's dangerous to approach these devices because so much of it is in one spot - spread it over a few city blocks as described in the article and the dose rates simply cannot remain that high. You might not want to hang around, but using words like "uninhabitable" seems over the top.
But suppose they're right. Unless very finely ground, the stuff will settle rapidly and won't go so far. And its radioactivity tells you exactly where it is, so you can find it easily and clean it up. If only this were true of anthrax. Cleanup would be expensive, but in many cases could be automated to limit human exposure to radiation.
The IEER was cited as a "nuclear watchdog" group. At least they weren't called impartial. Their site would have you believe that they are an objective clearinghouse of information, but the disingenuousness is in the details.
Read this about what happened when some people were contaminated with and ingested Cs 137 in Brazil