Where does energy go when no load is attached to a generator? In my understanding, electric power we use at home is produced by generator in the same way we watch a live streaming TV show. If the generator stops spinning, we don't get electricity. The electricity is not saved in a huge storage and then delivered to us.
Assuming there is no loss during transmission, the nuclear fuel power needed to rotate the generator is equal to the generated electric power. If no load consumes the generated electric power,  where does the nuclear fuel power go?
 A: As a side note, I assume that when you say "atomic fuel," you're referring to nuclear power, but not many countries get very much of their electric power from nuclear power. A more common case would be that the generator is run from an engine that burns fossil fuels.
In the situation you describe, they would run the engine driving the generator at low power or turn it off. But if for some reason they kept the engine running at full power, it would need less torque to crank the shaft of the generator when the generator's circuit was an open circuit. You would get some frictional heating in the moving parts (and maybe some energy dissipated in sound and vibration). Conservation of energy would still be satisfied, although it's possible that you'd burn out the equipment because of all the heating.
A: When the current flow through the generator does to zero (open circuit, no load) the torque requirement for moving the coils through the magnetic field falls to zero and the only engine power being consumed is due to friction in the generator bearings and generator cooling fan.
