You know what? I'd give the whole superheroism gig a try. Keep an eye on the comic book store shelves for "The Phantom Clenching Adventures of ASS-LESS CHAP!!".
Depending on the size of the bomb, and your distance you might actually be fine. If you survive the initial blast, shower, change clothes, and leave the area quickly you may not have any noteworthy issues at all. Or you could see the blast, and get cooked at a cellular level and die horribly a few days later.
They were right that dirt and concrete do wonders to stop gamma rays.
Hopefully, now, they're smaller and farther away. Ideally, they're farther away in time also.