Nuclear power plants work by using radioactive materials that are spontaneously breaking down. These materials give off a lot of energy in the form of heat. The heat is then used to warm water up...
Nuclear fuels like uranium or plutonium release huge amounts of heat energy, this heats water which tuns to steam. This steam turns turbines, which turn a generator, whch creates electricity.
I cant really understand exactly what you are saying but if you are talking about the motor it varies upon what car you have, but most engines are piston engines that have a piston on top of a rod...