Even though we can split atoms, what do we do with the energy? Boil water!
Even the internal combustion engine is taking advantage of expanded vapors aka steam power.
That’s the right way to do it; nuclear subs that use steam turbines don’t need a refuel for about half a century.
Most power plants that use other fuels, i.e. chemical reactions rather than nuclear, don’t use the hot gases from the combustion to turn the big turbines either; they use steam. Some are combined-cycle plants that use both hot gas and steam.
Don’t forget our coal power plants that produce power from steam!
A lot of folks don't consider that fact. We could create "Star Trek" tech like a warp core and we'd use it to turn an armature.