Energy world

Energy sources: Nuclear

Status: Non-renewable

What is it?

Nuclear power is generated by splitting heavy atoms of uranium into lighter ones by firing neutrons at them. This process is called nuclear fission. As the atom splits, it releases more neutrons, which then split more uranium atoms, releasing more neutrons and so on. This is a chain reaction which produces lots of heat energy.

In a nuclear reactor, this reaction is controllable because the uranium fuel is not highly concentrated. The speed of the reaction is also precisely controlled by inserting rods into the reactor which absorb neutrons.

How is it used to generate electricity?

The heat produced by nuclear fission is used to heat water. This produces steam, which pushes against the blades of turbines causing them to spin. The turbines are connected to generators, which create electricity. The steam generated in modern nuclear power stations is lower pressure than coal and oil stations.

Where can you find uranium?

Several places across the world. Canada is the largest exporter, but Australia has the most uranium.

Advantages and disadvantages of using nuclear power to generate electricity


Uranium is readily and cheaply available, and nuclear fuel is easily stored

A small amount of nuclear fuel produces a lot of electricity

Nuclear power stations do not produce any carbon dioxide from nuclear fission


Nuclear power stations may be unpopular with people who are concerned about how safe they are

Nuclear energy is not renewable. When uranium runs out it cannot be replaced

Nuclear energy produces radioactive waste which must be buried in sealed containers for a long time

Nuclear power stations cannot be switched on and off easily

How many stations in the UK?


How much does it cost to produce?

Between 2.5p and 4p/kWh

What is the carbon cost?

Nuclear fission does not produce carbon dioxide.

The future?

All but one of the UK’s existing nuclear reactors will be shut down by 2023.