I think using the word 'nothing' gives the wrong impression.

Hunkering down and actively avoiding any activities that would increase exposure (such as going outside or ventilating the house or leaving the basement) would be a more complete way to express the concept.

There is also the complexity of the fallout cloud footprint. If it wasn't your city that got hit, the fallout cloud will go downwind. Perhaps skeedaddling out of the fallout footprint would be the way to survive. This of course depends on having knowlege of the detonation and the winds aloft pattern for the next day or two.