system
Given the following post, respond as if you're commenting on Reddit:
human
How would Nuclear Propulsion work?

I want to know how it would work. But most of all, how it could successfully be done without damaging the ship. Also would it be in space or on the ground?
gpt
The most basic form of nuclear propulsion is a Nuclear Thermal Rocket (NTR). There was actually a program to develop this back in the 60's it was called NERVA. In this case, all you do is use a nuclear reactor to heat an inert gas (like CO2) and blast it out the back. So an NTR is really nothing more than a nuclear powered flying tea kettle.

You do however, get performances 2 to 4 times better than the best chemical rocket engines, so there's that.

Another very basic, but amazingly effective, idea is to use nuclear warheads. Project Orion would geared towards this before Cold War treaties banned the use of nukes in space. The idea is simple, have a rocket (with a huge buffer on it) drop nukes behind it which would then explode, and push the rocket forward. Provided they explode fairly close together (about 5 per second) then the acceleration is fairly uniform its not jarring. Its also one hell of a propulsion system. It's quite feasible for an Orion rocket to get up to 4 or 5% of light speed.

It would, obviously, only be used in deep space you couldn't use that on the ground, but since there's plenty of radiation in space anyway, setting off nukes isn't an environmental hazard.