The primary purpose of a nuclear reactor is to generate electricity by harnessing the energy released from nuclear fission.

Nuclear reactors can use uranium, plutonium, or thorium as fuel. Uranium is the most common fuel, and it is typically enriched to increase its concentration of fissile isotopes.

Nuclear fission is the process by which a heavy nucleus, such as uranium or plutonium, is split into two or more smaller nuclei, releasing a great amount of energy.

A moderator is a material used in a nuclear reactor to slow down neutrons, which increases the probability of their being absorbed by fuel nuclei and causing fission.

Control rods are inserted into or withdrawn from the reactor core to control the rate of fission by absorbing neutrons.

A coolant is a fluid that is circulated through the reactor core to remove heat from the fuel and other components.

A pressure vessel is a large, thick-walled container that houses the reactor core and prevents the release of radioactive material into the environment.

A containment building is a structure that surrounds the reactor core and is designed to prevent the release of radioactive material into the environment in the event of an accident.

A turbine is a device that converts the mechanical energy of a rotating shaft into electrical energy.

A generator is a device that converts mechanical energy into electrical energy.

A condenser is a device that removes heat from the steam produced by the reactor and converts it back into water.

A feedwater pump is a device that pumps water into the reactor core to replace the water that is converted into steam.

A pressurizer is a device that maintains the pressure in the reactor coolant system to prevent boiling.

A containment spray system is a system that sprays water into the containment atmosphere to remove heat and reduce the pressure.

An emergency core cooling system is a system that provides cooling to the reactor core in the event of an accident to prevent the core from overheating and melting.