With over 435 nuclear power reactors operable in 31 countries I would say that Nuclear Power is a popular source of green energy worldwide. But how much do you know about it?
Where it comes from? How is it harnessed? Well, in this article, we will learn together about the nuclear energy concept (fusion and fission) and we will also discuss some advantages and disadvantages of this type of energy.
What is nuclear energy?
We all know that everything around us (including our bodies) is made up by tiny little objects called atoms. Most of the mass of an atom is concentrated in the nucleus (the center) which is surrounded by a cloud of electrons. Despite the very small size of an atom its components are held together by a significantly large quantity of energy, called nuclear energy.
During the World War II, in their search of new powerful weapons, people have discovered that in certain circumstances an atom can split in two releasing a large amount of energy. Using this energy in a chain reaction, people have created nuclear bombs. It seems like during wars people get more and more inventive in their ways to destroy one another. After the war came to an end, this new technology had more peaceful uses in propulsion of submarines and production of electricity.
Fusion vs Fission
There are two fundamental nuclear processes used in energy production: fusion and fission. In nuclear fusion, green energy is released when two atoms combine and form a bigger atom (this is how the sun produces energy, by constantly combining its atoms).
In nuclear fission, the atoms split in two releasing a large quantity of energy. The nuclear energy power reactors use the latter process in electricity production. The machines inside a reactor control nuclear fission of particular isotopes of uranium. The atoms are forced to split, releasing so-called fission products that create chain reactions and these reactions release heat.
The heat warms the cooling agent in the reactor (usually water or liquid metal) and turns it into steams. The steams created by the nuclear fission turn turbines coupled to generators producing electric energy.
Nuclear energy: main advantages
First and foremost, the use of nuclear energy in producing electricity allows us to reduce the energy produced by conventional fossil fuels. Consequently, by reducing the use of oil and coal we reduce gas emissions and soil contamination. In operation, nuclear power plants emit nothing in the environment except hot water. So, they saves millions of lives by only displacing air pollution.
The nuclear waste (if handed properly) can be disposed without affecting in any way the planet. What is really interesting is that coal also contains uranium and by burning coal we generously release a radioactive dose of waste 100 times bigger than nuclear plants. Why do we still use conventional fuels?
Another advantage is that a nuclear reactor needs less amounts of fuel and that means that we can save a lot of money in producing, handling and transporting electricity.
The most important thing to have in mind is that the energy production is continuous. A nuclear power plant is generating green electricity about 90% of the hours of the year.
Because nuclear power does not depend on natural aspects, it overcomes the main disadvantage of renewable energy: solar and wind power as they depend on hours of sunlight and wind and these hours don’t always coincide with the hours of greatest energy demand (we mostly use heat and lighting at night, when there is no solar light for example).
Disadvantages of Nuclear Energy
We already established that nuclear energy is a clean, eco-friendly, sustainable energy source. Then, why people don’t rely more on it to produce the necessary electricity?
Firstly, a very important drawback of this type of energy source is the difficult management of nuclear waste. It takes many years for this kind of waste to lose its radioactivity and danger.
Nuclear power plants have a limited life. The generator becomes fragile and the risk of a terrible accident is very high with the years passing. Remember what happened in Chernobyl and Fukushima?
Moreover, the investment for the construction of such a power plant is very high and you need to recover quickly, so this drives up the cost of electricity generated. In other words, the power generated is cheap compared to fuel cost, but it becomes significantly more expensive when we want to amortize the construction cost.
But the main fear people worldwide have is that nuclear energy can be used as an extremely dangerous weapon. It was only one time that nuclear bombs were used in a military attack (during the World War II, when two nuclear bombs were released over Japan) and since then many countries have signed a Non-Proliferation of Nuclear Weapons Treaty but the threat still exists.
Nuclear energy today
Sixteen countries depend on nuclear energy in approximately a quarter of their electricity. France produces about three-quarters of its demand, Czech Republic, Hungary, Slovakia, Slovenia, Sweden, Finland, Switzerland and Ukraine get one-third of power from nuclear power plants. USA, UK, Spain, Russia and Romania produce one-fifth of total energy, while South Korea and Bulgaria get more than 30% from nuclear energy.
Japan has dropped significantly the use of this energy source after the disaster of Fukushima, but they are planning to return to the level they had before (about one-quarter).
Among other energy resources, nuclear energy produced about 19% of the global electric energy in 2014 and this number is expected to increase in a few years. Take a look at this diagram showing electricity generation in 2014, by source: