As climate change becomes more and more of a reality, humanity must turn to alternative resources. There is a great deal of controversy surrounding nuclear power, especially after the Chernobyl series been released. It is crucial to understand, however, that not all nuclear energy source is the same, and we should consider this when determining whether it is a good alternative energy source, or not.
It won’t be a surprise if I say, that the very first working nuclear power plant was in Obninsk (Soviet Union back then). Its production of electricity did not last long. It was only grid-connected from 1954 to 1959. After that, it served as a research facility, until 2002 when it was finally shut down. But the most important factor in this is, that nuclear power started its journey at this point. But what is happening exactly in a nuclear power plant?
Conventional nuclear power plants produce energy today by nuclear fission. It is a truly amazing discovery, and the science behind it is mesmerising. In 1938 Lisa Meitner and Otto Frisch (both physicists) discovered that a Uranium nucleus can split in two, and also realised that the byproduct is energy. It didn’t just change the way we produce energy, but also lead to the atomic bomb later.
To better understand the process, we will need to touch the structure of an atom. But don’t worry, we won’t go into too much detail!
As you can see, in the middle of an atom there is something called nucleus. The nucleus is made up of neutrons (no charge), and protons (positive charge). Around the nucleus electrons (negative charge) are “orbiting”. In nuclear fission, the nucleus is hit by neutrons, and the impact causes the nucleus to split in two. Two new atoms are formed in the process. Sometimes when the nucleus splits, additional neutrons are released in the fission. This will then cause a chain reaction by providing more neutrons that can hit the new atoms. Nuclear power plants today use Uranium atoms to produce energy. But why was this such an amazing discovery?
Nuclear fission isn’t just producing energy, it is producing a tremendous amount of energy! The energy produced by 1kg of Uranium equals to the energy produced by over 10000 litres of oil, or almost 20000 kg of coal. In the nucleus protons and neutrons are held together by a force called ‘strong interaction/nuclear force`. That is why they stay together. The neutron hitting the nucleus breaks this interaction or force, and all the energy that was used to keep the nucleus together is now released.
In nuclear fusion, the exact opposite happens. While fission requires the atom nucleus to be split in two, during fusion they combine the nucleus. This, however, only work with small atoms, such as Hydrogen isotopes. The problem is, that due to the same charge in their nucleus protons repel each other. That is what we call the Coulomb force.
Fusion is something that we see very often, but having difficulty so far to recreate. How is that? The fusion of Hydrogen atoms creates helium. This is the energy source, that powers the Sun. Fusion reactors today use Hydrogen isotopes (such as tritium or deuterium), as these atoms require less temperature to fuse than the Hydrogen isotope itself. Only 1 g of these isotopes can produce as much energy as over 10000 kg of coal.
However the problem with fusion is, and the reason why we still cannot grid-connect a fusion plant is a temperature issue. To break the above-mentioned force, that makes protons repel each other in Hydrogen atoms, an enormous amount of temperature is required (as previously said, the Sun gains its energy from fusion as well). How can we recreate the environment the Sun provides for fusion, and how could we possibly build anything that withstands that heat? Fusion has been on the horizon for a very long time, but I believe that one day we will harness this power.
The not so beneficial side of nuclear power
As an environmentalist nuclear power is rather concerning. Although there are various methods to manage the radioactive waste produced by the power plants, none of them is totally risk-free. There is a very interesting statement on the Stanford University website. It says: ” 1 tonne of fresh fuel rod waste from a nuclear reactor would give you a fatal dose of radiation in 10 seconds if placed 3 meters away.”. This is rather alarming. Although the fission process itself does not emit carbon dioxide, the mining of uranium surely does!
Another important factor to consider the existence and evolution of nuclear weapons. In 1945, more than 75000 people died in Nagasaki as a result of a nuclear explosion. A few days earlier more than 130000 in Hiroshima for the same reason. This was exactly 74 years ago. The soviets then tested the Tsar bomb, in 1961. This was over 3000 times more powerful then the bomb dropped on Hiroshima. Today we have even more powerful weapons, and the number of them grew dramatically.
The destruction that nuclear power can cause and environmental concerns due to uranium mining and radioactive waste makes this alternative source rather controversial. What do you think?
Read more in the Endangered Species series:
Or read about the Keeling Curve: