Thor has shown that he can use Mjolnir to absorb massive amounts of energy. He's also specifically did so against The Presence (Russian guy with powers based on radioactive energy), so he's done so against a person as well. If Doc Samson can build a machine that could drain all of Hulk's energy (which he did), then I honestly don't see why Mjolnir couldn't do the same.
That was the example I was thinking of and could not remember. That was in the Avengers right when the rest of the nonimmortal team was down?
Almost the entire team had been turned into radioactive zombies and Thor thought they were dead and freaked out.