The short /easy answer is: a Chernobyl-like accident would never happen in the USA in the first place - the reactors are better designed, they have a containment building and much better trained operators.
This said... this is a pretty good question anyway.
Delta Force - for a long time the cynical in me tell me
"we were lucky that Chernobyl happened into an authorian society - a society that did not hesitated sending thousands of soldiers into the inferno to clean the mess"
Fact is, no robot could have done the job.
But of course the world would be better had Chernobyl never happened in the first place.
Had some asshole general not terrorized the reactor operators during the test drill, for example...
My opinion is, I can't see a democracy sending soldiers (cannon - radiation ? - fodder would be a more adequate term) cleaning up the mess the way USSR did. No way.
Unless of course every single men can be outfitted with a radiation-proof suit. But in turn that would take a lot of time to produce (600 000 liquidators cleaned up the Chernobyl mess !) - and during this time the nuclear volcano would continue to erupt.
Hell, that's a bleak scenario. Kind of putting democracy against a wall.