Ukraine

Not a physicist but bet it would take more than that.

Thanks for the optimism though. Two recent bestsellers on the topic of "nuclear war would be bad" were getting me down.
I have a degree but that doesn't make me a physicist all these years later. If a physicist were compounding that list of the needed it would likely include everything surrounding the kitchen sink. But like me they probably would want the houses bathtub, and pass on including that kitchen sink.

The bath tub is water basin large enough to feed the thirst of several people for several days. I'm going to shelter in the bathroom because that is where the tub is, and because if is very small, as far as for air filtering it is doable. I also have a large tank of water out in the yard I can dip up water from.

Another thing is I'm going to look at exposure of fallout as being something to minimise, I would have no reasonable expectation to avoid getting some dosage. I.e. I'll dress for it, and go out to get stuff, just avoiding doing it too much. Then I will clean up and change clothes before going back into the shelter. Everything I carry will be wiped down.

I still have and use KN95 masks. They will be handy for when I'm going out to get things.