[Tuxedo]

Typically, a "dirty-bomb" is a low-yield nuclear bomb that releases cobalt-60 and iodine-131 as byproducts. These have a long half-life (60 years or so) and would render the area inhospitable to life for several generations. You could design one to result in both massive devastation and longterm toxicity. The bomb would be normally set off as a conventional device using TNT, PETN, or even a lot of C4. A small version of an A-bomb can be equipped to release cobalt-60 and iodine-131 as well. Since it releases radiation, it can be termed a nuclear device, even though it may or not be a fission or fusion bomb. This is a scary situation. Let's hope the reports are untrue. I would expect that is such a device is detonated here in the USA, that it would leave us no choice but to retaliate with SLBMs at Afghanistan. I do not know if we still even have ICBMs.

[apackof2]

How big is this bomb?
I read in a previous post that is is quite large and
wouldn't it pose a burden to manufacter and transport to a location
that the terrorists want to target?
More information on manufacturing process/transportation,
detonation and factoring in all of these what would be most feasiable
locations to target?