Fusion Energy: An Ultimate and Inexhaustible Source of Energy for Million of Years

Ever wondered how the sun is glowing for billion years without being dark for a moment? What is the fuel for the sun? The answer is fusion energy.

But what is fusion power or fusion energy?

When two nuclei fuse to create a large nucleus, a tremendous amount of energy is evolved and called fusion energy.

Atomic nuclei are positively charged and repel each other due to Columb’s force. If you overcome this repulsion they fuse to create a bigger nucleus.

In a fusion reactor, a large amount of temp (about 20M degrees celsius, more than the sun’s core temp) is applied, which dissolves the fuel positive nuclei and negatively charged electrons. This mixture of nuclei and electrons is called plasma.

Due to immense temperature and pressure, the nuclei come close enough to merge and release an energy of about 17.6 MeV. In this process, the fuel used is a mixture of deuterium and tritium. These both are isotopes of hydrogen. Deuterium is very abundant in nature, but tritium is rarely found and is radioactive. The total amount of tritium in the world is only 200kg, but it can be prepared by bombarding neutrons on lithium metal.

The by-product in this reaction is helium gas which is not radioactive. Also, the output mass of the helium is slightly less than the input mass of deuterium and tritium. This difference is converted into energy by the Einstein equation E = mc².

Three conditions must be necessary for fusion in the reactor;

1. High temperature
2. High particle density
3. Sufficient amount of confinement time for plasma before turning again into gaseous form

Fusion Energy vs Fission Energy

Fission energy is practically possible to harvest. In fission, the heavy nucleus like the isotope of Uranium 235 is bombarded with a slow neutron splitting them into two nuclei with emission of a large amount of energy. But due to some reasons fusion energy is far better than fusion energy.

Benefits of Fusion Energy

1. Fusion energy is far more reliable and better than fission energy due to the following reseasons
2. The energy released in the fusion process is four times greater than the fission reaction.
3. The fuel of nuclear fusion is easily available. Deuterium could easily be found in seawater and tritium can be prepared by irradiating lithium metal.
4. Nuclear waste of fusion reaction “helium” is not radioactive making it the green form of energy. However, Nuclear waste of the fusion process contains heavier elements like Barium and Krypton and are radioactive.
5. Fission energy is an inexhaustible source for millions of years like the sun is working 24–7 for more than 4.5 billion years.

Reactors types

There are two types of reactors based on the confinement of plasma.

1. Magnetic Confinement Reactor or Tokamak

As discussed above, fuel is heated up to 20M degrees celsius to make plasma containing free positively charged nuclei plus negatively charged electors.

Here comes an issue of confinement of plasma because 20millilon C temp is a considerable amount that can melt anything in its path.

For that reason, plasma confines in a donut shape stream of gas with the help of a strong magnetic field to keep it away from contact with the reactor’s walls.

Plasma is heated up with the help of laser beams, strong microwaves, and electric currents.

ITER fusion reactor in France is a magnetic confinement type.

2. Inertial Confinement Reactor

In inertial confinement, a small amount of fuel, deuterium plus tritium, about a few millimeters dia of pellets are heated and compressed at an enormous amount of density to achieve fusion.

For that purpose, energy is delivered to the target with the help of laser beams. The density ranges from 100 to 200 times the density of a liquid.

Is fusion energy possible? When it will be available?

Yes, sure it is possible. Many breakthroughs are happening in this field, like UKAEA Research Breakthrough, which recently happened in May 2021.

According to many experts, it will be available to the grid around 2035. Fusion energy is a way to a bright future that is going to change the world entirely.