There's hippy FUD, and then there's actual engineering info. Guess which one I got.

Nuclear reactors carriers operate with a "closed loop" cycle: nuclear fuel is sealed in a container, where it heats a fluid. The fluid flows out, does some useful work, and flows back in. The working fluid becomes highly contaminated, but so long as it doesn't leak out, everything's okay.

In nuclear aircraft designs, the working fluid would be the outside air. No container, no shielding, no closed loop, just air flowing over raw uranium fuel at supersonic speeds, heating up, and shooting out the back of the plane carrying all manner of crap along with it.

Saying that nuclear aircraft and nuclear carriers are equally safe is like claiming that big pool of flaming gasoline is as safe as a working car engine, because hey, they're both burning gasoline right? The issue is *containment*.

Now, in principle you could design a fully contained nuclear aircraft engine, which indirectly heated the air using a working fluid inside sealed plumbing, with heat exchangers. However, that extra crap adds a ton of weight, and nobody's managed to design one of those that will get off the ground.