[knak]

one more thing, how do these search teams have a clue where to look? I don't mean which cities, but once they get to a particular city. What do they do? Look under bridges and junk like that?

[Semper Paratus]

but once they get to a particular city. What do they do?

10 - maybe 15 years ago there was said to be an A-bomb scare in Boston. What was said to be done was vehicles going over main routes than neighborhoods scanning for trace radioactive signatures that spill from an unsophisticated device like droppings from a garbage truck.

[Sean Osborne Lomax]

I am told they use highly sophisticated and sensitive radiological sniffers. I believe general searches are from heliborne/aircraft sensors, then the ground crews come in for the detail work when they find a hot spot.