What is nuclear energy and can it help stop climate change?

How is nuclear energy made?

Nuclear energy is created by the process of nuclear fission - when neutrons are used to split atoms apart, resulting in large releases of radiation and more neutrons, which in turn split more atoms in a controlled chain reaction. Once the atoms are split, the released radiation heats up the water in the nuclear reactor generating steam, which turns a turbine,  producing collectable energy.

Why is Uranium used as fuel in nuclear fission?

Light water reactors, the most common nuclear reactors, use uranium-235 because it is relatively unstable enough to split apart easily and releases a lot of energy after nuclear fission. The uranium is placed in water, which controls the reactive process and is turned into steam, which helps generate the electricity. 

Uranium-235, however, is highly toxic and releases noxious fumes, and must therefore be handled with expert care. It is also not the most common form of uranium, and must therefore be generated from other isotopes of more commonly found uranium through a process called “enrichment”.

There are, however, newer technologies that use thorium as fuel for nuclear reactors, which is considered much less toxic and generates much more energy than uranium. 

How efficient is Nuclear Energy?

Compared to fossil fuels, nuclear energy is a much more efficient energy source, generating as much energy with 200 tonnes of uranium as is made with 3,500,000 tonnes of coal. Moreover, this amount of energy can be generated by only one tonne of thorium in newer reactors.

Which countries use the most Nuclear Energy?

In 2020, fossil fuels continued to be the world’s predominant sources of energy, making up 83 percent of the world’s energy mix. By contrast, nuclear energy only generated about 4.3 percent of the energy mix. The United States is the largest consumer of nuclear energy (30.8 percent of the world), followed by China (13.8 percent), France (13.1 percent) and Russia (8 percent), per BP’s Statistical Review of World Energy.

Some countries have stopped depending solely on fossil fuels for electricity and have turned to renewable sources and nuclear energy instead. In France, for example, nuclear energy produced 67 percent of its electricity in 2020, while in Sweden, nuclear accounted for 30 percent and hydropower accounted for 45 percent of its energy mix.

What are the cons of Nuclear Energy?

Potential accidents 

The terrible accidents of Chernobyl and Fukushima immediately come to mind when people think of nuclear energy. Accidents such as these could potentially release dangerous levels of radioactivity into the surrounding environments of the nuclear plants. However, it is important to note the rarity of these occurrences due to the strictness of building and operation procedures in the western world. One should also put into perspective that nuclear energy has caused much less deaths than fossil fuels.

Radioactive waste 

Since some of the waste from nuclear energy is highly dangerous, effective waste management is crucial, although sometimes costly. However, the highly radioactive waste - the remnants of the uranium fuel from within the reactors - accounts for only 3% of total nuclear energy-production waste. These waste products are mostly placed in huge drums of concrete or steel and buried hundreds of metres below the Earth’s surface. 

What are the pros of Nuclear Energy?

Cleaner source of energy 

Nuclear energy does not give off harmful pollutants and carbon dioxide the way burning fossil fuels does. It therefore does not contribute as much to global warming as other energy sources.

Safer source of energy 

Because of its low-emission rate, nuclear energy results in much less human casualties compared to the mortality rate of fossil fuels. By contrast, the WHO estimates that 4.2 million people die each year from pollution caused by burning fossil fuels. 

Is Nuclear Energy a solution for climate change?

Making the shift to renewable energy as quickly as possible is key to preventing catastrophic man-made climate change. However, whether or not societies can actually make this shift quickly enough to prevent the IPCC’s 1.5 degree level of global warming is challenging. The change to solar or hydropower is costly, still in its incipient stages, and sometimes unreliable. Many experts suggest that using nuclear energy as a transition source between fossil fuels and future renewable technologies is key to reducing the irreparable harm of manmade climate change.

Photo by Nicolas HIPPERT