@Mtntopview Just quickly looked up all the properties of a Nuclear warhead detonation. Well, it really depends on what kind of Vampire it is, I mean, if we're talking those crazy Jiangshi (Chinese vampires. The kind where you have to lock lips with the sucker and suck the last breath in its corpse out in order to kill the fucker.) i'd say, maybe not... But, if we are talking about your bog standard vampire that is weak to sunlight, then I would say yes.
When a Nuclear warhead detonates, for the first few seconds of the explosion, the entire area is flooded with infrared, visible and ultraviolet rays. Which are all hallmarks of solar radiation. This effectively turns ground-zero into something resembling the surface of the sun for a few seconds. So, I would say that, by their "Sunlight kills them" rule, I think that would work.
But, ultimately, if their entire body is vaporized, they would also die. They can't spontaneously come back from nothing (Unless, again, it's a Jiangshi, because those things are fucking insane)