The nuclear reactor

How can you use rocks dug up from the ground to make electricity for light and heat in our houses? ... How does a nuclear power plant work? -- To start with, you need fuel. Usually it's uranium, and that's mined here, in the uranium mine. Uranium is taken from the mine to a factory where it's enriched. In uranium that exists naturally in the ground, almost all the atoms are stable.

For uranium to be usable in a nuclear power plant, we need to increase the proportion of unstable uranium atoms. That process is called enrichment. Then the enriched fuel is placed in long rods, which will be used in the nuclear reactor. This is the reactor. All the nuclear fission happens here, generating energy.

As soon as enough unstable uranium is gathered in the same place this reaction starts spontaneously. The uranium nuclei are split into smaller pieces, launching neutrons. These neutrons in turn, hit other nuclei, and split them. We have a chain reaction. With every fission, a large amount of energy is released.

This energy heats water, and makes it boil. The steam is led through a pipe and makes a turbine spin. The turbine then drives an electricity generator. Now, the fission of the uranium nuclei has created electricity that brings light and heat to homes and industry. The steam is piped back to the reactor.

On the way, it's cooled off, and before it reaches the reactor it has turned to water again. In the reactor, the water is heated and vaporised again. -- And runs the turbine. -- And the generator... It's important to control this reaction, so there are control rods in the reactor. The control rods absorb neutrons and slow down the process. If you pull them out of the reactor, the number of fission reactions increases, and if you push them in, the number of fissions decreases.

If you have to, you can make an instant emergency stop. When the control rods are pushed in all the way, all fissions stop. The reactor stops. There are large benefits with nuclear power. The nuclear power plant itself has no carbon emission.

The mining, transport, and enrichment of uranium requires energy, but nuclear power's contribution to the greenhouse effect is quite small. You can get vast amounts of energy from relatively small amounts of fuel. And nuclear power is reliable in the sense that it functions equally well, regardless of weather and winds, unlike several of the renewable energy systems. But there are disadvantages too. The most important one has to do with safety.

On several occasions, the chain reaction has gone out of control. Radioactive substances have leaked, people have died, and large areas have become uninhabitable for a long time. And also, the waste products need special handling. The used fuel is radioactive and dangerous, and is usually buried in the ground for a hundred thousand years. So there are various opinions on whether nuclear power is good or bad, but at least now you know how it works.

It starts with rocks dug up from the ground, and it "ends" with the remains being buried again. ... And in between: nuclear power.