in a segment discussing nuclear power plant safety. I'd seen it before some years ago but it was still just as impressive.

The chances of successfully using the "airliner as missile" technique against a nuclear powerplant are pretty small. First of all, it'll be harder to hijack another airliner like they did that day. Second, the reactor is a much smaller target than a skyscraper making it a lot harder to hit. Finally, the containment domes on reactors are so massively built that even a heavily laden airliner moving at high speed would be unlikely to break through, much less destroy the reactor underneath.

That isn't to say that nuclear powerplants aren't viable terrorist targets. The biggest concern seems to be infiltration by ground forces. For that reason, security has really been increased at the plants. I hope this helps you rest easier. We still have to be on guard but the odds that you'll be endangered are pretty slim.