Nuclear Energy

Introduction

Nuclear energy is the energy contained in the atomic nuclei which is released in nuclear reactions and radioactive decay. Currently, nuclear power is one of the most common and dangerous forms of electricity generation. In 2012, nuclear power plants using this energy were producing 13% of the world’s electricity and 5.7% of the total world energy production (World Nuclear News 2016). Since the discovery of nuclear energy in the 1940s, it has been a cause of thousands of deaths but also proved to be one of the greatest discoveries of the 20th century. The amount of energy that could be produced from a small amount of fuel is amazing. According to rough estimates, the energy that is released during the fission of 1 kilogram of uranium can be compared with the energy that is produced from the combustion of 2 500 000 kg of coal. However, it does not stop the debate about the use of nuclear energy (MacKenzie 1977) Opponents of nuclear energy (in particular such organizations as “Greenpeace”) believe that the use of nuclear energy is threatening mankind and the environment (Sturgis 2009). Advocates of nuclear energy (IAEA, World Nuclear Association, and so on), in turn, argue that this type of energy can reduce the emissions of greenhouse gasses into the atmosphere and with a normal exploitation bears significantly less risk to the environment than other types of power generation (Martin 2006). This paper will examine the usage history and main working principles of nuclear energy and nuclear energy plants.

History of Invention of Nuclear Energy

The first scientific research in the field of nuclear power started 2500 years ago. The ideas of the ancient Greeks became the starting point of knowledge about the structure of matter. They stated that every body is made of specifically connected, invisible, and indivisible elementary particles – atoms. In Greek, “atom” means “indivisible” (Herzog 2013). However, ancient atomistic views have been forgotten for many years. For about a thousand years, academic science had not been developing. Science was replaced by theology. In Renaissance, atomistic view re-emerged. Frenchman Pierre Gassendi suggested that atoms are combined in small groups for which he even came up with the name – molecule (Herzog 2013).

In the current understanding of science, the discovery of the neutron in 1932 by James Chadwick can be considered the beginning of modern nuclear physics (Herzog 2013). A plenty of the outstanding scientists and researchers have contributed to the development of knowledge on nuclear power learning the basic principles of nuclear energy. They laid a solid foundation for the science about atoms. A huge number of great researchers from all around the world have created a consistent theory of the atom. There were many important discoveries and works that led to the splitting of the atom’s nucleus (Herzog 2013).

The study by V. Roentgen “A New Kind of Rays” published in 1895 gave a start to the history of mastering nuclear energy. They received the name X-rays. In1896, Becquerel discovered that uranium ore emits invisible rays having high penetrating power. Some years later, radioactivity was explored (Herzog 2013). In 1898, M. Sklodowska and Pierre Curie isolated a tiny volume of a new substance, the element that emits particles. They named it polonium. Later, they opened radium (Herzog 2013).

Then, in 1932, the scientist Chadwick discovered neutral nuclear particle which has no electric charge. It was a neutron, which subsequently played a key role in nuclear power development. In 1934, Enrico Fermi found that when bombarding uranium with neutrons, radioactive elements are produced. Italian researchers thought that they are elements which are heavier than uranium and thus called them transuranic (Fermi 1938).

In 1936, Frenkel made an exact model of the nucleus and introduced thermodynamic concepts in nuclear physics. Also, he was the first who formed and described the theory of nuclear fission. In 1938, Hahn and Strassmann repeated the experiments of Fermi; they found that when neutron is put in the nucleus of uranium, a nucleus falls apart. It is divided into two smaller nuclei. This discovery was a great success.

Later, in 1939, the scientists from the USSR Khariton and Zel’dovich theoretically demonstrated the possibility of a chain reaction of uranium-235 nuclei fission. It was found that the power released by the decomposition of one kilogram of uranium is much bigger than that obtained by the burning of a huge amount of the best coal. Also, in the USSR, it was discovered that the spontaneous fission of uranium nuclei s possible. The scientists have shown that the uranium nucleus can decay spontaneously. In a year, Khariton and Zel’dovich proposed a calculation of the chain reaction of uranium fission. Thus, they have set the fundamental conditions for its implementation. They stated that when uranium is mixed with certain substances (such as heavy water), it creates chain decay of uranium by branching chains. They established that even weak neutron irradiation will cause a massive reaction (Herzog 2013).

Just in a few years after this breakthrough, the whole world engaged in the active construction and launching of nuclear power plants. Due to these inventions, the most advanced development of nuclear power plants occurred in the Soviet Union. There, in 1954, for the first time, nuclear power as a source of energy in the industrial sector has been realized in the form of a nuclear power plant. In 1956, the history of the development of nuclear energy began in the United States as well. Sweden and Switzerland were some of the first countries where the development of this area was going very quickly. By 1984, these countries became leaders in energy production. Belgium was slightly inferior (Herzog 2013).

An active development of nuclear energy plants continued until 1986, the date of the accident in Chernobyl. The scale of the disaster was so huge that scientists around the world unanimously insisted on the complete abandonment of nuclear energy claiming that the planet will not sustain one more nuclear catastrophe. However, the story of nuclear power is not over to date.

Working Principles

This type of energy is produced and utilized not only in nuclear power plants. It is also used on nuclear submarines and icebreakers. Fuel is still necessary for the normal functioning of the nuclear power plant. Typically, uranium is used for this purpose. This element is widespread in nature, but it is difficult to get it. In nature, there are no uranium deposits. It is uniformly distributed throughout the surface of the earth. The richest uranium ores, which are very rare, contain up to 10% of pure uranium (Walker 2004). Uranium is commonly found in the uranium-bearing minerals as isomorphic substitute element. However, with all this, the total amount of uranium in the world is grandiosely large. Perhaps in the near future, the latest technologies will allow increasing the percentage of uranium mining.

Nuclear energy is produced as a result of the chain reaction of nuclear fission of certain radioactive elements. Uranium-235 or plutonium is typically used. Nuclear fission starts when neutron gets inside the nucleus. A neutron is a subatomic particle without charge, but having a relatively large mass (it is 0.14% higher than the mass of the proton) (Walker 2004). As a result, fission fragments and new neutrons are formed. New neutrons with high kinetic energy are actively transformed into heat. It is the process of the nuclear explosion.

The operating principle of nuclear power plants is to a large extent similar to the action of fossil fuel power plants. The main difference lies in fuel. In a nuclear power plant, uranium pre-enriched natural ore is used. The steam is produced by nuclear fission, not burning of oil, gas, or coal. Nuclear power plants do not burn fuel, thereby avoiding atmospheric pollutants. The process can be described in the following steps:

1. Tiny uranium particles, which are called atoms, fission;

2. During the fission, more small elements of the atom – neutrons – are released;

3. Uranium neutrons collide with atoms; as a result, heat, which is needed to generate electricity is produced (Walker 2004).

Nuclear decay is one form of power generation, which is used at power plants. It is a process of slow and controlled release of energy by atoms fission. Nuclear fusion is the process of quick and dangerous release of energy by combining atoms. Nuclear energy is the most efficient form of electricity production today. A tiny particle of uranium with the size of a golf ball carries the same amount of energy as 2.3 million pounds of coal. Such a huge amount of energy is produced from uranium in a nuclear reactor. A nuclear reactor is something like a furnace for uranium. Inside, there goes on an extraordinary reaction through which energy is released partly in the form of heat. The released thermal energy is used to boil water. Boiled water enters the heat exchanger which transfers heat of water to the reactor with fresh water. Fresh water turns to steam, and the steam drives a turbine (Walker 2004).

In the US, two different types of nuclear reactors are currently used. One type is boiling water reactors. Their working principle consists in boiling water which is transformed into steam. The steam comes into a turbine connected to a generator. After that, a condenser cools the steam and it turns back into the water. Then, it is re-used in the same process.

The second type is pressurized water reactors, where the water is put under pressure. The pressure heats the water but does not allow it to boil. The water in the reactor and the water in the steam generator is never mixed (Walker 2004).

Conclusion

Using the atom energy is becoming increasingly important. World reserves of oil, gas, and coal are gradually depleted; their extraction is becoming more expensive. Therefore, new alternative sources of energy are needed. Nuclear energy is one of the solutions to energy problems. The discoveries in the field of nuclear physics have created a scientific basis and laid the foundation for the development of nuclear power. After people became aware of the characteristics of the fission of atomic nuclei as well as basis of managing and controlling the nuclear power – (how to create the conditions for the beginning of nuclear reaction, its maintenance or shutdown), it became clear that humanity received a real opportunity to extract energy using their knowledge of the deep atomic and nuclear level of the structure of matter. If one day all sources of supplies of traditional energy on the planet will be over, perhaps, nuclear power would be the only source that really would be able to replace them. Nobody can deny its benefits; however, possible consequences should not be forgotten.