Engine or motor?
An engine is powered via a thermodynamic process (burning of fossils fuels, nuclear fuels, etc).
This is why the thrusters on a rocket are called rocket engines (not rocket motors). Most have no moving parts but produce thrust by the burning of fuel and oxidizer through a nozzle.
In a nuclear power plant the reactor is the heat source for the steam engine that produces power to run the turbines which rotate the power generators.
A motor is powered by electricity.
just my $.02,
Bob
BSME (Bachelor of Science in Mechanical Engineering)1989, University of Maryland