Nuclear power generation uses the fuel uranium to produce electricity. Uranium is a highly concentrated energy source that is available throughout the world in large quantities. 1 tonne of uranium can produce as much electricity as 2000 tonnes of coal. Once uranium has been used, it can be reprocessed and recycled to make more fuel. During the reprocessing, plutonium is given off as a by-product. The plutonium can then be used to generate power in fast reactors.

Electricity is generated in a nuclear power plant when an extra neutron is added to the nucleus of a uranium atom. This causes it to split apart and release heat energy. As the nucleus splits apart, several neutrons are released, which can then collide with another nucleus and cause further fission of uranium atoms. This leads to a chain of reactions. The heat produced during fission converts water to steam, which then turns a turbine and generates electricity. In a power station, the amount of energy release is controlled to provide an even heat supply.