Final answer:
The five main parts of a fission reactor are the nuclear fuel, moderator, coolant, control rods, and shield and containment system, all of which work together to facilitate the controlled nuclear fission process to generate electricity.
Step-by-step explanation:
Nuclear fuel: A fissionable material like uranium or plutonium is needed to sustain a controlled chain reaction. It is contained in fuel rods.
Moderator: Slows down neutrons produced by nuclear reactions, increasing the probability of additional nuclear reactions.
Coolant: Carries heat from the fission reaction to an external boiler and turbine, where it is transformed into electricity.
Control system: Consists of control rods placed between fuel rods, which absorb neutrons and adjust the number of neutrons to maintain a safe rate of the chain reaction.
Shield and containment system: Provides protection from radiation and keeps the radioactivity contained, even in the event of a nuclear accident.
The nuclear fission process in these reactors generates heat, which is then used to boil water and produce steam. The steam drives a turbine connected to a generator, creating electricity.