[Mariner]

"not gonna tell how i know this....not gonna tell what has personally happened to me...what I can say is this...there is no way, no how, that a nuke, dirty or otherwise, is gonna end up here in this country....the only way a dirty bomb is gonna go off here, is if the people that want to do that can get the crap here, without importing it...this is where you start your preventive measures.."

While it's true a uranium based bomb is relatively easy to detect...plutonium is a whole nuther program. Easily shielded and much more difficult to detect.

Of course they are MUCH more difficult to produce as well...and certainly traceable to source.

[Mariner]

In fact, state of the art detection for "clean", weapons-grade PU239 (assuming 6% contamination of PU240) is a couple of miles, at best. And that's unshielded. Add an inch of lead and you're not likely to detect it next door.

Sailors sleep within a few feet of W-88 warheads without harm.

Yes, a Uranium bomb can be "seen" from at least 100 miles. But, for shielded Plutonium, it's virtually undetectable.

http://www.berthold.com/downloadfiles/rp/en_ieee_tns99_lb6414.pdf