Efficient? No. Effective? Maybe.
Anything dealing with an Antediluvian fundamentally can't be represented with the V:tM mechanics very well. At 10 dots, any Discipline is capable of anything the Storyteller can conceive-- their descriptions are even listed as Storyteller device, and nothing more!
The right vampire with the right stats and Disciplines can absolutely shrug off one (or more) atomic blasts (the Ravnos Antediluvian is the only explicit example of this I'm aware of). Even for Ravnos, two nuclear bombs, plus the combined assault of several Antediluvian-similar figures from Kindred of the East, were not enough to actually kill it. It was sunlight that ended it (though it's unclear if the sunlight caused damage Ravnos otherwise resisted, or if sunlight was just one type of damage among many and happened to strike off the last hit box).
But more importantly, a vampire old and powerful enough for a hunter to assume a nuclear weapon and massive innocent, collateral casualties is the best approach is also a vampire likely to be sufficiently smart, well-informed, and well-resourced to become aware of the plot in advance, and/or already has contingency plans to deal with such an assault.
Even a mortal can survive a nuclear blast if they're in a properly built underground bunker. If the plan is to get a nuclear bomb in the immediate vicinity of the Antediluvian and set it off, that's going to be extremely difficult to pull off for anyone. Especially a mortal.
Sunlight and True Faith are consistently shown to be the most reliable ways to counter vampires, as they have little to no ability to resist either (and in the case of True Faith, can offer some resistance to some of vampires' supernatural abilities). A hunter wouldn't necessarily have enough information to know all of this, and may indeed think that a nuclear weapon is the best plan, but it's definitely not guaranteed to work.
If you'd like to look at the specific references to Ravnos' final battle and destruction, Revised is the best source I'm aware of at present. The story is spread out across many of the books in the Time of Judgement series and across many product lines.
Key references can be found in ToJ books for Mage: the Ascension (that's where the nuclear weapons came from), Vampire: the Masquerade, and Wraith: the Oblivion, and the updated version of the Ravnos clanbook.