Designing a plane that could fly on nuclear power has been tried before early in the nuclear age. I don’t know if technology exists today to make it practical, but making it safe in the event of a crash is another story.

People generally think of black boxes on planes as indestructible, and they are pretty tough. But they’re good for protecting a few memory chips from impact and thermal forces. But even though the boxes are in the tail and designed so that the entire front of the plane acts as a crumple zone, there have been crashes where the black boxes were never found, even though the crash location was known and on land. Now imagine trying to build a containment vessel for some sort of reactor that can keep a plane crash from turning into a dirty bomb while also being light enough to be flown on a plane that also has to carry passengers and cargo.