Comment Re:Come now. (Score 2) 104
Plutonium has a half life somewhere between thousands and millions of years. It's too stable for use as a dirty bomb. For something to be a radiological threat it would have to have a half-life on par with a human lifespan, or much shorter.
Typically a dirty bomb is used to scare or kill people off long enough that the area is abandoned but not so long that the attacker could not take over the area for their own use. Even if the attacker did not want to make use of the bombed area, and just wanted to deny it's use to anyone, something with a long half life is still undesirable. The longer the half life the more material the bomb would have to carry to irradiate a given area. With a half life of thousands of years there would have to be 100x more material than if a material with a half life of tens of years.
A more practical dirty bomb would use something like cobalt, tritium, cesium, strontium, or polonium.
Another problem with plutonium in a dirty bomb is that it's relatively inert chemically and very dense. Cleaning up plutonium would be almost trivial since it does not collect in the body, sinks like a stone in water, and only reacts with the most caustic of chemicals. Tritium would make drinking water and plant life radioactive for decades. Strontium likes to collect in the bones and irradiate people from the inside out.
Plutonium on the other hand likes to wash off, collect at the bottom of things, isn't taken up by plant or animal life readily, and has a half life so long that even if it collects in the body is unlikely to decay within a human life span.
You know, I scare myself sometimes that I know this stuff.