…Actually the Bikini Islands might work. The US military did a lot if testing there early in the cold war, so it would be a little deferent, but still fit right in to the FO world.
They show a lot about it in a pretty famous documentary about that period called “Atomic Cafe” which the folks who made Fallout obviously watched.
You should check it out, you won’t really understand FO world unless you watch this… http://www.youtube.com/watch?v=RHGa9nUbDww