We, as living creatures, rely upon the well-being of planet Earth for our own survival. A quick glance at the news and one will notice that we’re not doing such a great job at keeping ol’ Mother Nature healthy. Global warming this, pollution that – we’re not very good guests, are we? I say this, but it’s actually very difficult for our bustling, resource-reliant society to function without the things that do harm to the environment. Our only hope is to constantly be on the lookout for more efficient, cleaner methods that we will be able to sustain into the future. And, as always, science is the way forwards.
Since forever, humans have used fire as a source of energy. Essentially a portable Sun, this fire could be used to provide warmth, light and as a means of preparing more easily digestible (and need I say, tasty) meals. The only things you need are some sort of fuel, and a way to spark the flame. Over time, with the appropriate development of technology that led to such things as the Industrial Revolution, we obtained bigger, better pocket-Suns that could meet our energy demands. All the while, the Earth’s crust wastes away as we pick at its valuable resources, burning them and releasing toxic products into the atmosphere. It is obvious to anyone that we need to find a better way of creating this energy.
One such method that has been in practice since the 1950s is nuclear fission. At first glance, the word ‘nuclear’ might put some people off due to some certain *ahem* negative connotations, but what if I told you that it is more than a million times efficient than burning fossil fuels? On top of that, using energy from nuclear fission does not produce any of those unwanted greenhouse gases. Win-win, right?
First I’ll explain what nuclear fission is. As we should know from previous posts, the atomic nucleus consists of neutrons and protons. The tightly packed protons, which all harness a positive charge, repel each other due to electromagnetic repulsion. The strong nuclear force is what holds these particles together to form the nucleus. As we go up the periodic table, elements gains more and more neutrons, and more and more protons. Eventually the nucleus becomes too big that the strong force cannot hold it together anymore – we say that it is unstable. This nucleus will try to achieve a balance of protons and neutrons by shedding them off via radioactive decay. Nuclear fission is simply one form of this whereby the large nucleus splits into two smaller ‘daughter’ nuclei which are more stable. The process also produces free neutrons and a lot of energy.
Humans have learnt to exploit this phenomena in order to harness the vast amounts of energy given off through the interaction. By firing a neutron at a large radioactive nucleus such as Uranium – 235, the size of the nucleus is increased further, making it even more unstable. It will immediately break down into two smaller nuclei, and release an incredible amount of heat, as well as other neutrons. These neutrons go through a similar process, being absorbed by other Uranium nuclei, creating a chain reaction of nuclear fission. Past this part, a nuclear power plant runs in pretty much the same way as any fossil-fuel burning site might. All the heat is passed into a large vat of water, which evaporates and runs through steam turbines, generating electricity.
As you’d might expect, this nuclear stuff comes with its own downsides. Because the substances used are radioactive, they’re harmful to the environment and humans if exposed. Therefore lots of money is spent to ensure proper transportation and storage, as well as on the nuclear plant itself. Any sort of contamination could be devastating. Just take a look at Chernobyl. Another inconvenience comes from having an immense amount of radioactive waste which cannot be disposed of easily. Every year, all the plants in the world combined leave behind over 2000 tonnes of waste, which requires even more money to store safely. Nuclear fission clearly isn’t ideal but it’s the best solution we have currently in my opinion.
As long as Homer Simpson isn’t running our nuclear power plants, I think we’re safe for the time being…