Texas Tech's Wind Science and Engineering Research Center does work in this area, and it is of greater interest to them than some DHS bureaucrat: I believe test structures of theirs have had "unscheduled testing" by tornadoes in the past.

PS. As for unexploded warheads: it's the short-lived isotopes that tend to be the problem more than long-lived isotopes since there's more energy emitted per second. Pu-239 is the main problem in a warhead and it has a half-live of ~ 20,000 years. Assuming it doesn't embed itself in something that acts as a moderator it shouldn't be that hard to clean up...

A more realistic problem than an unexploded nuclear warhead in the backyard is if some idiot decides to put a nuclear reactor in low-earth-orbit again and then has an uncontrolled re-entry long after criticality, something like Cosmos 954 in 1978. Neither the Russians nor Americans do that any more but others have the capability and might be tempted to try it. Not much to do but stay clear of anything that looks like debris and wait for clean-up crews to clear the area...