Nuclear power plants – a remedy for the energy crisis or a real threat to life? What are they and how do they work? What disasters related to the operation of nuclear power plants have occurred so far? You will learn everything from the text.
We have known about the existence of atoms for over two thousand years. Later proving their existence and isolating the smallest particle (electron) turned science and technology upside down. The first reactors began to be built and their safety was widely debated. Unimaginably huge amounts of energy with great ecological potential, or a lethal weapon that threatens our world? The topic of nuclear power plants is still very controversial. Where did they come from? How do they work? What are their benefits, and what should we be careful about?
The world’s first nuclear power plant and the history of nuclear energy – how did it come about?
In 1897, Joseph John Thomson discovered the electron, for which he received the Nobel Prize a few years later. Only half a century later, the world’s first nuclear power plant was put into operation – 1954. It was created in the city of Obninsk, about 100 km from Moscow, and its power was only 5 MW (mega watts). In 1955, however, a PWR (Pressurized Water Reactor) test reactor was opened at the Shippingport nuclear power plant (USA). Early nuclear energy, contrary to appearances, was not intended to produce new sources of electricity. The main task of the new reactors was the development of nuclear weapons technology.
In the 1970s, the popularity of nuclear power grew rapidly. Annually, around 20 nuclear reactors were put into operation around the world. Everything was going great. The power plants, operating at high speed, were at the same time almost failure-free. However, in the following years, due to two dangerous accidents in Three Mile Island (1979) and Chernobyl (1986), states began to question the construction of new nuclear power plants and slowly withdrew from such investments.
The situation calmed down somewhat with the entry into the 21st century, and plans to generate electricity from atom in Europe were once again taken into account. This is, of course, related to new challenges that appear before mankind – excessive carbon dioxide emissions, rapidly shrinking deposits of fossil fuels, as well as the constantly growing demand for electricity. This forces us to look for alternative and more efficient sources of energy.
Operation of nuclear power plants – what are they and how do they operate?
Nuclear power plants operate on the principle of atomic fission, and the most important resource for their proper operation is uranium enriched with isotopes. The most basic variant of operation and commonly used in Europe are PWR nuclear reactors. Inside them, as a result of the fission of atomic nuclei, huge amounts of heat are generated, which in the primary cycle end up in the water under very high pressure. They pass through the steam generator and then give off all their stored heat output to boiling water at a lower pressure (secondary circuit).
The resulting steam passes through the drying system to eliminate water molecules. If H2O droplets were to enter the drive turbine, this could be seriously damaged. The dried steam feeds the steam turbine and the reactor generator. This, in a nutshell, is the production of nuclear electricity. However, let’s try to picture it another way.
How and why is the chain reaction process controlled at a nuclear power plant?
With the fission of atoms, we are able to obtain colossal amounts of energy. However, to be able to enjoy nuclear energy, you need to master it first. Why is learning to control so important?
As you already know, virtually every nuclear power plant uses enriched uranium as nuclear fuel. Each single atom fission reaction results in a rapid capture of neutrons. Each fission of the element uranium represents another three neutrons ready to drive further reactions. Some of them run away too much and, as a result, never come into contact with fissile matter. Part of it is absorbed by the stable isotope nucleus.
However, in order to avoid the reactors being shut down, one in three neutrons must end up in an unstable isotope nucleus. It is also necessary to select the appropriate mass of fissile material and its size. Too small amounts can also lead to lapse itself.
A defined and controlled amount of time must pass from the moment of nuclear fission to the capture of a neutron by the next unstable nucleus. In the event that the reaction period begins to accelerate rapidly compared to the previous ones, there is a risk of an explosion. The well-known atomic bombs work well on the principle of rapidly accelerating neutrons.
Construction of a nuclear reactor – or how do nuclear power plants protect themselves against dangerous explosions?
Nuclear reactors are specially constructed in accordance with safety standards. Their heart is a core containing fuel elements (rods) and a moderator. The rods are nothing more than the form in which the fuel is delivered to the reactor. On the other hand, the moderator’s task is to slow down neutrons with water, graphite or beryllium oxide. Its task is also to increase the chances of catching neutrons.
Control bars are responsible for the reaction process. With their help, the level of neutron capture is controlled, increasing or reducing the number of molecules. One of the most important elements is the safety bars. They are inside the reactor in case of a sudden deterioration and loss of control. During an emergency, they are placed in the core and the reactor is immediately shut down.
The greatest disasters in the history of nuclear energy
So far, we have recorded four major accidents in nuclear power plants. At first glance, this may seem like a meaningless number. However, it should be remembered that the effects of a single molten core can be felt by a large portion of the human population. Moreover, the harmful environmental radiation caused in this way can persist for hundreds of years. Let’s take a look at the chronologically ordered, most dangerous accidents of four nuclear power plants.
Failure at Lucens Nuclear Power Plant
1969 near Lucens, Switzerland. The reactor was damaged in an experimental low-power nuclear power plant. No one was killed or injured or seriously irradiated. However, all protective barriers failed and were destroyed. Only the walls of the cave in which the reactor was located saved us from a much more serious catastrophe.
The accident at the nuclear power plant in Three Mile Island
The most serious nuclear accident in the USA. In 1979, on the artificial island of Three Mile Island, the core of reactor 2 was partially melted as a result of an accident. Here, too, no one was seriously hurt. However, this incident had decisive socio-economic consequences. Since then, there has been no attempt to build new power plants in the United States for a long time, and public support has fallen sharply.
Chernobyl Disaster – Reactor Explosion
The largest and probably the most famous of all four disasters. Everything happened on the night of April 25-26, 1986. The Chernobyl nuclear power plant is located in Ukraine near the city of Pripyat. The overheated core of the reactor (unit 4) led to a strong explosion followed by a fire that spread huge amounts of radioactive substances. The consequences of this incident were catastrophic. An area of about 120,000 – 140,000 hectares was contaminated, and the radioactive cloud spread to all corners of Europe.
Nuclear Power Plant No.1 Fukushima Nuclear Power Plant in Japan is not a single incident, but a series of accidents. The events took place in 2011 and were caused by the tsunami that resulted from the earthquake. The core melted in as many as 3 reactors. As a result, radioactive substances were released into the environment and contaminated the seawater. Dangerous events also reached Fukushima Nuclear Power Plant No. 2, but the situation was brought under control.
Nuclear power plants – the biggest advantages and disadvantages
As you can see, it is not without reason that the opinions on the production of nuclear energy and the construction of subsequent reactors are so divided. The above four cases undoubtedly contributed to the split of society on this issue. Nevertheless, with appropriate procedures and safeguards, we are able to reap unquestionable energy and ecological benefits. So let’s consider all the pros and cons.
Nuclear power plants and their advantages
- Reduction of carbon dioxide and other dust emissions into the atmosphere – replacement of coal and fossil fuel power plants and switching to nuclear power plants;
- Low production costs – it is even by up to a third cheaper than other technologies;
- Endless Energy Source – Unlike other endless energy source alternatives, atomic power will last for thousands of years for all mankind.
Disadvantages of nuclear power
- High construction and renovation costs – power plants are quite expensive to maintain, as is their construction, which in addition takes a very long time;
- Risk of failure – guidelines for the construction and security of power plants are at an increasingly higher level. However, this does not change the fact that a single mistake can have terrifying consequences;
- Radioactive waste – the question arises here how to safely store it, so that it does not contaminate the environment.
The largest nuclear power plants in the world
There are about 450 nuclear reactors in operation worldwide. Asia is by far the world’s largest investor in nuclear energy. Surprisingly, however, the US is now the largest producer, followed by countries such as France and China. Several items on the list are really impressive. Here are the 7 most powerful nuclear power plants.
- Kashiwazaki-Kariwa nuclear power plant in Japan (7,965 MW)
- Bruce nuclear power plant in Canada (6,384 MW)
- Kori nuclear power plant in South Korea (6,040 MW)
- Hanul nuclear power plant in South Korea (5,928 MW)
- Hanbit nuclear power plant in South Korea (5,875 MW)
- Zaporizhia Nuclear Power Plant in Ukraine (5,700 MW)
- Gravelines Nuclear Power Plant in France (5,460 MW)
With nuclear energy being such a great part of everyday life, it seems inevitable that it would become more popular. However the more immediate and spectacular nature of nuclear energy failing scares the public more than a slow poisoning with CO2. What do you think? Will nuclear power be the solution to the energy crisis or the end of humanity?