On the Nuclear power page we covered all of the components of a nuclear fission reactor. This page demonstrates the key ideas in action.
In a chain reaction, more neutrons are produced by a nuclear fission reaction than are needed to react. This is a good thing - it is essential that the nuclear reaction rate is maintained for ongoing electricity generation.
An uncontrolled chain reaction is used in nuclear weaponry.
When a neutron is absorbed by a uranium nucleus, it's binding energy per nucleon increases. This makes the nucleus too unstable and so it splits to release this energy.
If the mass of fuel is insufficient, the neutrons will escape without causing further reactions.
Natural uranium contains mainly 238U, which does not split when it absorbs neutrons. The fuel is enriched with 235U to increase the likelihood of a successful reaction.
Nuclear energy (fuel) → thermal energy (steam) → mechanical energy (turbine) → electrical energy (generator)
Use quizzes to practise application of theory.