>>12755272It's feasible but not practical.
It makes sense for large, slow-moving craft like aircraft carriers and submarines. So those already exist. But not cars. Conceivably it could work on really large tanks, but it's simply not worth the additional weight allocated to reactor shielding and all the additional safety protocols. Also, large tanks themselves have proven impractical since WWII. Maybe trains, but trains need rails. And if you have rail infrastructure, you can just electrify that. So technically, an electric train connected to a nuclear powered grid, kind of IS a nuclear powered vehicle.
In general, it's not worth it for land vehicles. It makes sense for sea craft because weight is less of a concern and you're constantly surrounded by coolant. Also, when you're at sea it's a sort of "alien" environment. Ie: you can't just jump off a boat the way you can step off of a truck. You can't just pull up to a gas station in the middle of the ocean. So it's really important that such craft can have really long-lasting power sources. That's also rally useful for stealth, in the case of subs.
What about aircraft? Being stuck in the air definitely justifies fuel longevity. Both America and the Soviet Union had nuclear plane programs back in the 70s like you said. Like many useless cold war era programs, they were motivated by fear the other guy would perfect it first, rather than inherent practicality. So when one country gave up on the project, so did the other.
The issue was that aircraft need to be light as possible, but heavy shielding is needed to protect the pilot from radiation. Too much, and it won't fly. Too little, and the pilot dies. Thee wasn't an acceptable sweet spot that justified the costs and constraints.
Now, 40 years later, what if there were a way to make a plane without an onboard pilot? It's a crazy idea, but I'm sure if the military figured out how to exploit this synergy, they'd be very transparent about it.
