Why Fusion is Energy of Dreams
A few months ago, KSTAR, Korea’s nuclear fusion research device, announced that it succeeded in maintaining the world’s first 100 million degrees Celsius Plasma for 1.5 seconds.
With the world’s efforts to study fusion energy, this success has made Korean fusion energy research a step ahead of other countries.
Fusion energy is a dream energy that solves the energy shortage problem of mankind at once. It is also the energy of the sun.
What is fusion energy?
The atoms that make up matter are at the center of which there are atomic nuclei consisting of protons and neutrons and electrons are circulating around them. At high temperatures, however, the atomic nucleus and the electrons are separated into plasma states. The light atomic nuclei in the plasma state move at high speed, collide and combine with each other, and become a heavy nucleus, which is called the fusion reaction.
The mass of the nuclei generated is smaller than the mass of the two nuclei before collision. At this time, the disappearing mass turns into energy, which generates enormous energy according to the formula of Einstein’s special relativity theory, E = mc² (E is energy, m is mass, c is speed of light), which shows the relationship between mass and energy.
Because the speed of light is about 300 million m / s, if all 4 g of mass of one 50-yen coin turns into energy, E = 0.004 kg × (300 million m / s) The generated energy is 36 x 10 & lt; 10 & gt; kJ. This energy is equivalent to the electricity available for one year in a city with a population of 80,000, assuming an average power consumption per household of 5,000 kWh.
The reason why stars such as the sun shine is due to fusion energy.
The sun is mostly composed of hydrogen, the lightest element, and its central part is a plasma state in which atomic nuclei and electrons are separated, because it is a high temperature of more than 15 million degrees. Thus, at the center of the sun, a fusion reaction occurs in which a hydrogen atom nucleus is bound to another hydrogen atom nucleus and transformed into a helium atom nucleus.
There is enormous energy in this fusion reaction, which is the energy source of the sun that continues to shine for billions of years.
To produce the fusion reaction that occurs in the sun on Earth, it needs a temperature of 100 million degrees, which is much higher than the sun. The center of the sun is compressed by strong gravity, so the density of the atoms is so high that the atoms collide easily even at a temperature of 15,000 degrees centigrade, but the earth is not such an environment.
Ultimately, to build a fusion power plant, you need to create over 100 million ultrahigh-temperature plasmas that are not on Earth, and you need a vessel that holds this plasma. But materials that can withstand temperatures of 100 million degrees Celsius do not exist on Earth. So, a technique of putting an ultra-high-temperature plasma in a vacuum vessel and hiding it by magnetic force and not touching the wall was developed.
The fusion of the fusion power plant is a donut-like device surrounded by a huge electromagnet. Deuterium and tritium, which are fusion fuels, are put into this vacuum device, and when it is heated, it becomes a plasma state.
Due to the lines of magnetic force generated by the electromagnet, the plasma does not directly touch the vessel wall, but rotates in the apparatus. Plasma deuterium and tritium collide with each other when the temperature reaches 100 million degrees Celsius, causing a fusion reaction. The energy generated by the fusion reaction boils water to make steam, which turns the generator to generate electricity.
More research and time are needed to commercialize the fusion power generation, which can be called artificial solar power. Scientists predict that by about 2050, fusion energy can be commercialized.
Why fusion energy is a dream energy?
The fuel for fusion is deuterium and tritium, deuterium can be obtained by electrolysis of seawater, and tritium can be made by reacting lithium and neutrons in a fusion reactor. Lithium is rich enough to contain about 230 billion tons of seawater, so there is no risk that the fusion fuel will run out.
Fusion power generation also has little radioactive waste and does not generate greenhouse gases and pollutants. And, when an abnormality occurs in the fusion reactor, it is very safe because the plasma is designed to cool itself and stop the fusion reaction.
In addition, fusion power can produce more than seven times more energy than nuclear power with the same amount of raw materials. Because of these advantages, fusion energy is often referred to as ‘dream energy’ or ‘future energy’.