How is electricity made in a nuclear reactor?

Answer 1

Electricity is made at a nuclear power station by creating a controlled nuclear chain reaction, fission, in the reactor core. This fission process generates heat, lots of it, due to the release of binding energy corresponding to the loss of mass in the core. A coolant, usually water, keeps the temperature from reaching excessive levels. In the BWR (Boiling Water Reactor) that coolant flashes to steam. In the PWR (Pressurized Water Reactor) that coolant heats other coolant which flashes to steam. The steam spins a turbine / generator which makes electricity. The steam, which has now been condensed back to water by the turbine and condensor is reheated and fed back to the core (BWR) or steam generators (PWR) to repeat the cycle.

The purpose of a nuclear reactor is to create and sustain a fission chain reaction in order to produce heat to make steam to drive turbines and produce electrical power (extremely simplified explanation).

A fission chain reaction is the interaction of neutrons with fissile materials (elements that can be fissioned, and that go on to produce more neutrons). Some enriched fuel (such as uranium-235) is introduced into the reactor core. It produces neutrons as radiation. If more fissile material is present, that interaction repeats to make more neutrons, and so on. A nuclear reactor is designed to sustain a fission chain reaction and control the rate at which that reaction occurs.