You dont need a bomb shelter. You need enough food/water for a week, some survival skills, and some knowledge about nuclear weapons. I'm talking about limited nuclear strikes too. If we go all out with the Ruskies, I imagine anyone living near a population center or military base (most everyone) will have at least a half dozen ground zeros in their immediate area - enough to make all planning moot. It wont be the fallout though, it'll be from the blast.