In general I'm a nuclear critic/skeptic, but in this case I agree, the nuke idea may not be that outlandish. Nothing else has worked. Is it not possible to engineer a nuke to yield more heat and less radiation? The engineering has worked in the other direction...
My main worry would be that the explosion makes a bigger hole instead of sealing the hole.
My main worry would be that the explosion makes a bigger hole instead of sealing the hole.