Here in the UK a friend has restored to usable condition an abandoned cold war bunker.
Some years ago they purchased land that included a small bunker and originally only regarded this as an interesting relic of the past.

Recently they have cleared out all the junk, steam cleaned and repainted and stocked the shelter.
These shelters are quite basic and rather small, about 7 feet high, 7 feet wide, and 18 feet long.
No air filtration or specific radiation protective measures are installed, but the simple fact of being 20 feet below ground is said to reduce the radiation to one five hundredth of that received on the surface.
Originally no mains services were installed, but I have added grid electricity. This is unlikely to be available after TSHTF, but whilst times are normal grid powered lighting, a dehumidifier and a battery charger are useful.

(BTW, I know that this is a very old thread, but the points raised are still relevant and I saw no point in starting a new thread on the same subject)