Are you referring to the detonation of tons of high-explosive which have basically been deposited into a spent-fuel pool? Because, other than that, just about nothing could cause such an incident at the plant that I worked in before moving a year and a half ago. You can't accurately hit such a small target (the pool) with a large passenger/cargo plane loaded with the appropriate explosives; you can't load a Cessna with enough to do the job. Outside of that, pretty much everything is isolable, for near-to-absolutely-zero-release capability. The vast majority of the rest of the really dangerous (radioactive) stuff is inside the several-feet-thick containment structures. You can hit those with an airliner and you'll shut the plant down on seismic shock - but the attack will basically just crack and spall some concrete, maybe tear up some outer-layer rebar.

I won't presume to speak for ALL US nuclear plants - but the threat you propose does not appear to be a credible one at the plant I worked at.

You got a mad on for nuke plants, or what? Or is it that you just fear what you don't understand?