Water gets heated into steam, steem pressure drives turbine, turbine drives generator.
Steam then gets cooled and turned back into water and the cycle starts again.
The heat source can be nuclear or coal but since you said reactor, I assume you mean nuclear.
The ELI5 version: when certain materials are brought near each other, they heat up. A lot. This is how they heat the water to drive the system I described above.
Latest Answers