How does nuclear power work?

How do we turn nuclear energy into usable power?
02 February 2021

Interview with 

Eva Higginbotham


Cartoon schematic of an atom


If you want to discuss the neccesity of nuclear power, you should start by setting the scene. So here’s Eva Higginbotham to explain: What is Nuclear Power, and how does it work?

Eva - Nuclear energy comes from the cores, the nucleus, of certain atoms. You can make this energy by smashing nuclei together, which is nuclear fusion. This is why the Sun gives out light, but we haven’t quite figured out how to do that sustainably on Earth.

The other way is by breaking nuclei apart, which is nuclear fission. Nuclear power plants here on Earth work through fission.

Most (though not all) atoms you come across day to day, like most of the ones in you, or in your table, are stable. They don’t really change, and they don’t really feel like changing.

But some are unstable. We call these radioactive. This is because they have too much stuff in their nucleus. Carbon usually has 6 protons, and 6 neutrons in its nucleus. And it’s stable.

But Carbon-14 has 6 protons, and 8 neutrons. It’s unstable, and radioactive. Over time, it will decay, giving out energy until it turns into something else that is stable. We can harness that energy for nuclear power. Although not for carbon, it’s not nearly unstable enough.

Uranium is though. Uranium is so unstable that if you hit it with a neutron, it will break into two new nuclei, and will give out a few more neutrons. A tiny little bit of the mass of the uranium will be converted into energy, because E=mc squared. Energy = mass...times the speed of light squared. And a little bit of mass turns into a lot of energy. And the neutrons that were made can go off to break up more uranium atoms, and the cycle goes on and one

That’s the energy we use in nuclear reactors. The energy given off, is used to heat water, which turns into steam, and powers a turbine.

If there are too many neutrons, breaking up too much uranium, making too much heat it can be dangerous. But we have ways to control them.

Control rods are rods which control things. They’re made of elements that are good at catching neutrons, leaving fewer around to split uranium, slowing the reaction.

There have been some very high profile nuclear disasters, like Chernobyl in 1986 and Fukushima in 2011. But in general, when managed correctly, nuclear power is safe.

And renewable energy is not without its risk to life. Hydroelectric dams have burst, and people can fall from wind turbines. (although all renewable energies are much safer to human life than fossil fuels.)

So the debate in the industry is less concerned (although not unconcerned) with the question of “is nuclear power safe”, and more concerned with “is nuclear power necessary?”


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