[chakalakasp]

There are multiple plans for multiple contingencies. A couple of different examples are here:

https://github.com/davidteter/OPEN-RISOP

The fallout thing is kinda a unlikely thing. Fallout from typical ground-bursts is something that denies area for weeks at most.

There are weapons systems that can do area denial for much longer by using weapons salted with materials that will remain radioactive for many years (essentially the plot of Dr. Strangelove -- that "doomsday" system is based on realistic weapons possibilities, and the Russians in the past decade intimated that they have developed a submersible drone system designed to cross the ocean and detonate huge salted weapons to poison the U.S. coasts for decades https://en.wikipedia.org/wiki/Status-6_Oceanic_Multipurpose_... ) -- but as far as anyone in the open source info world knows, these kinds of weapons are not deployed.