system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are there nuclear subs but no nuclear powered planes?

Or nuclear powered ever floating hovership for that matter?
gpt
It's been tried! But nuclear generators are very heavy, especially with the kind of shielding that you'd need to actually protect your crew from being irradiated. If you're in the ocean, that's a lot easier since added weight just makes you slower, it doesn't change what you need to stay aloft.

For a plane, you gain the benefit of being able to stay powered almost indefinitely, but with the tradeoff of losing a lot of your capacity for crew and cargo.