Which is why it's wise to always be stocked up on ammo.
The problem with many "vaults" or shelters, is the filtration systems. You have to get fresh air without radiation in it. Same with water.
In a real world nuclear apocalypse, the only enemy we'd find would be the real world "raiders". I highly doubt "" or zombies.
Yeah, they'd be plenty of bandits, highwaymen and looters.
There wouldn't be "mutants" as such, there would however be many mutations, disfigured people/children, and I'm not sure what radiation does to the human/animal brain, but I assume there would be some mental/brian damage from prolonged radiation sickness. (Someone with more knowledge on the subject might be able to clear this up)
The closest thing to a Ghoul would be someone with severe facial radiation burns, so they'd look like a Ghoul, but everything else is fiction.
Overall, a Nuclear Apocalypse, regardless of mutants or whatever, is not something I'd wanna be apart of.