September 10, 2017 Nuclear Energy Written by Greentumble
Nuclear energy can be found all

around us! While this may sound like a very ominous message, it is quite simply the literal truth. Nuclear energy is the energy found in the nucleus, what is otherwise known as the core, of an atom. As atoms are the building blocks of the universe, nuclear energy is pretty much everywhere. Physicists consider that nuclear energy is what binds the nucleus together; this power is called “strong force” [1].

But beyond scientific circles, the term “nuclear energy” has a very different meaning. It has come to mean the energy we are able to extract from nuclear fission, the process whereby we split an atom of uranium making it release energy.

Where can we find uranium?

Discovered in 1789 by German chemist Martin Klaproth, uranium is a chemical element found in rocks in concentrations of 2 to 4 parts per million; it is as common in the Earth’s crust as tin, tungsten and molybdenum. It is a very heavy metal which scientists consider was formed in supernovas about 6.6 billion years ago [2]! It not particularly abundant in our solar system, but due to its radioactive characteristic it is the main source of heat inside the Earth, causing convection and continental drift.

Not all uranium that is found on Earth is the same; it comes in slightly different forms which are called “isotopes”. As such, it is not all uranium isotopes that can be used to produce nuclear energy. Indeed, it is only Uranium 235 (U-235) that is used for this purpose. It takes its name from the fact that the atoms of this isotope comprise of 92 protons and 143 neutrons – if you add those two numbers together you get a total of 235.

It is important to note that this uranium isotope represents only 0.7% of the uranium that can be found on the Earth’s crust. In other words, it is far from an inexhaustible resource. As such as lot of countries, such as the US, need to import it from countries like Australia, Canada, Kazakhstan, Russia, and Uzbekistan.

What happens with U-235 then?

Nevertheless, what is intriguing about this isotope U-235, is that under certain conditions it can be split, generating a lot of energy. The process for achieving this is rather technical but essentially, for nuclear energy to be produced, changes need to be made within the nucleus of the U-235 atoms. More specifically, when U-235 neutrons split this releases heat (a form of energy). If this happens enough times, many millions of times in fact, a large amount of heat can be produced from a small amount of uranium. The heat generated is used to make steam and in turn to produce electricity. This is essentially the process that takes place in nuclear power stations.

Given the very intricate and highly technical process that needs to take place, it would be difficult to argue that nuclear energy comes from uranium. It would be more accurate to say that nuclear power is found where there are nuclear reactors. Indeed, one could argue that nuclear energy is a type of energy that was literally created in a laboratory! If this is the case, then understanding better what happens in a nuclear power plant is definitely worthwhile.

Compared to a conventional power plant, uranium replaces the fossil fuels in a nuclear power station. The nuclear reactor ensures that a controlled procession of fission chain reaction can be achieved using U-235; it does so through a series of machines. The heat that is created is used to make steam which in turn spins a turbine and produces energy. We have relied on this technology for 60 years to produce energy that is considerably lower in greenhouse gas emissions, compared to fossil fuels [2].

According to the World Nuclear Association, a typical 1,000 megawatt reactor can provide enough electricity for a modern city of up to one million people [2] using about 200 tons of uranium each year [1].


Did you know?

Nuclear energy powers 15% of our energy needs and while there are over 100 nuclear reactors in the US, a lot of countries such as France, rely almost exclusively on nuclear power to meet their energy needs [1]. Globally, there are currently 447 operable civil nuclear power reactors around the world, with a further 61 under construction [3].

At the same time, there are very clear risks involved in nuclear energy. We have witnessed the catastrophic power of nuclear time and time again. In the first place, experts are concerned that storage facilities, where radioactive waste is stored, can leak, crack or become eroded. This means the radioactive material can contaminate the surrounding environment, in particularly the soil and water resources close to the facility. This is a clear health hazard for both people and the environment.

To put this in perspective, the 1986 steam explosion in one of the nuclear reactors of Chernobyl in the Ukraine caused immediate environmental problems. But these were not contained in the area of the reactor; fallout spread over the surrounding area and spread further afield with the wind and rainfall. Radioactivity traced back to Chernobyl fell as rain over Scotland and Ireland even though most of the radioactive fallout fell in Belarus [1].

So yes, nuclear power can be found in many places. From a science point of view, it is the power that binds matter across the entire universe; a power we cannot do without. But this great power requires great care and responsibility when we use it to power our own energy needs. Anyone with an environmental conscience would argue in favour of the curtailing of nuclear energy.

In the eyes of anyone who wishes to see a transition to a low carbon and sustainable future, the question would not be “where can nuclear power be found” but “where should nuclear power be”. And the response to that question would be in very few places, if at all.