Everything you didn’t ask to know about: Nuclear reactors

Nuclear reactors sound complex but the basic idea is actually pretty simple.

The principle of a nuclear reactor is simply to boil water super efficiently, and then use that steam to create electricity.

In fact, it is similar to generating electricity from a thermal power station, just replacing the boiler with a nuclear reactor. The fuel for nuclear reactors is uranium 235 - a small grain of uranium 235 has the energy equivalent of an entire tonne of coal.

These uranium 235 particles are sealed with metal tubes to form fuel rods, then the fuel rods are inserted into the pressure vessel. There are usually hundreds of fuel rods in each container.

The power of a nuclear reactor is regulated by control rods, which move up and down. For safety reasons, nuclear reactors are sealed in 6.6 foot thick containment vessels.

When a neutron strikes the nucleus of a uranium 235 atom, neutrons will smash the atomic nucleus into: Barium nuclei, Krypton nuclei and three neutrons. These three neutrons will continue to bombard the nucleus to form 9 neutrons, thus forming a chain reaction.

During this chain reaction, known as 'nuclear fission', huge amounts of energy are released as heat. Here's the boiling part: This intense heat from fission is transferred to water circulating around the fuel rods. The water gets really hot, hot enough to boil and turn into steam. This high-pressure steam is then piped to a turbine, which is basically a giant fan. The force of the steam spins the turbine blades, which in turn spins a shaft connected to a generator, then finally the electricity is delivered to the grid.

So, next time you see a nuclear power plant, remember, it might not be boiling water for your tea, but the basic principle is the same. Nuclear reactors use a controlled chain reaction to create heat, which boils water to spin turbines and generate electricity - all without the greenhouse gases of burning fossil fuels.

Source:

US Office of Nuclear Energy (2024) NUCLEAR 101: How Does a Nuclear Reactor Work? Available online at: https://www.energy.gov/ne/articles/nuclear-101-how-does-nuclear-reactor-work#:~:text=Nuclear%20reactors%20are%20the%20heart%20of%20a%20nuclear.

Find your science tribe. Sign up to our mailing list below for Science and Sip events and experiments to try at home!