Diagram showing how nuclear power is generated.
Nuclear reactors are at the centre of the power plant. A nuclear reactor is a device used to create and control a sustained nuclear chain reaction. Heat from nuclear fission is passed to a working fluid (water or gas) which runs through turbines, that spin to generate electricity, that is sent to the national power grid.
During nuclear fission a neutron collides with a uranium atom and splits it releasing a large amount of energy in the form of heat and radiation. More neutrons are also released when a uranium atom splits. These neutrons continue to collide with other uranium atoms, and the process repeats itself over and over again.