Nuclear Fusion

Nuclear fission and fusion reactions are the two fundamental types of nuclear reactions. Nuclear reactions are phenomena in which one or multiple atomic particles are created from the collisions between two nuclei or a subatomic particle and one nucleus . The nuclides created from nuclear reactions are not similar to the reacting nuclei (parent nuclei).

Table of Contents

What Is Nuclear Fusion?

Nuclear fusion is a reaction through which two or more light nuclei collide to form a heavier nucleus. The nuclear fusion process occurs in elements that have a low atomic number, such as hydrogen. Nuclear Fusion is the opposite of nuclear fission reaction, in which heavy elements diffuse and form lighter elements. Both nuclear fusion and fission produce a massive amount of energy.

Nuclear Fusion Definition

Nuclear fusion is when two or more atomic nuclei fuse to form a single heavier nucleus. In the reaction, the matter is not conserved because some of the mass of the fusing nuclei is converted to energy.

How Does Nuclear Fusion Take Place?

Let us look at the nuclear fusion example below to understand how the fusion reaction occurs.
Nuclear Fusion

When deuterium and tritium fuse together, their components are recombined to form a helium atom and a fast neutron. As the two heavy isotopes are recombined into a helium atom and a neutron, the leftover extra mass is transformed into kinetic energy.

The participating nuclei should be brought together for the nuclear fusion reaction to occur. They should be brought so close to each other that the nuclear forces become active and glue to the nuclei together.

Nuclear Fusion in the Universe

Every star in the universe, including the sun, is alive due to nuclear fusion. It is through this process that they produce an enormous amount of heat and energy. The pressure at the core of any star is tremendously high, and that is where the nuclear fusion reaction occurs.

Nuclear Fusion in the Universe

For example, the temperature at the sun’s core is around 15 million degrees Celsius. At this temperature, coupled with very high pressure, two isotopes of Hydrogen, Deuterium and Tritium, fuse to form Helium and release a massive amount of energy in the form of heat. Around 600 million tons of hydrogen are converted into Helium every second in the sun. The reactions which take place in the sun provide an example of nuclear fusion.

Difference Between Nuclear Fission and Nuclear Fusion

The table below lists the major differences between fusion and fission reactions.

Nuclear Fission Nuclear Fusion
Nuclear fission is a nuclear reaction that splits a heavy atom into multiple smaller ones. Nuclear fusion is a nuclear reaction that combines two or more small atoms to form a large atom.
It does not occur naturally. The universe is full of instances of nuclear fusion reactions. Every star uses it to produce energy.
It produces a large quantity of energy. It produces greater energy than the fission reaction.
It does not require a lot of energy to split an atom into two. It requires a lot of heat and pressure for the process to happen.

To learn the differences in detail, visit the article below:

Applications of Nuclear Fusion

We are still at an experimental stage as far as nuclear fusion reactions are concerned.

  • Clean: No combustion occurs in nuclear power (fission or fusion), so there is no air pollution.
  • Less nuclear waste: The fusion reactors will not produce high-level nuclear wastes like their fission counterparts, so disposal will be less of a problem. In addition, the wastes will not be of weapons-grade nuclear materials as is the case in fission reactors.

If appropriately utilised, nuclear fusion energy is the answer to the world’s power crisis problem. It is clean and produces a minimal amount of nuclear waste as compared to fission reactions. In addition, the fuel for fusion, Deuterium, and Tritium, are also readily available in nature. Thus, scientists are hopeful that fusion will be a viable alternative power source in the coming centuries.

Nuclear Fusion Reactor

Nuclear fusion reactor uses the principle of controlled nuclear fusion reaction. The energy is generated when two light atomic nuclei are forced to join together. When two nuclei merge, a small amount of mass (matter) is transformed into a huge amount of energy. This huge conversion can be explained using the equation:

\(\begin{array}{l}E = m c^2\end{array} \)
E = energy
m = mass
c = speed of light in vacuum
Mass (matter) can also be converted into energy by nuclear fission (splitting of heavy nuclei).

In the video, you will learn how to harness the energy produced by nuclear fusion reactions in a controlled manner.

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Important Questions on Nuclear Fusion

The environmental impacts of nuclear power results from the nuclear power cycle, its operation, and the effects of nuclear accidents. The greenhouse gas emission’s health risks are smaller than those associated with coal. Although nuclear power plants do not emit carbon dioxide, high amounts of carbon dioxide are emitted during operation and activities that are related to building and running the plant.
Nuclear fission power plants generate unstable nuclei; some of these are radioactive for millions of years. Fusion, on the other hand, does not create any long-lived radioactive nuclear waste. A fusion reactor produces helium, which is an inert gas. It also produces and consumes tritium within the plant in a closed circuit. Tritium is radioactive (a beta emitter) but its half-life is short. It is only used in low amounts so; unlike long-lived radioactive nuclei, it cannot produce any serious danger.
No, because fusion energy production is not based on chain reaction as nuclear fission. Plasma must be kept at very high temperatures with the support of external heating systems and confined by an external magnetic field. Every shift or change of the working configuration in the reactor causes the cooling of plasma or the loss of its containment; in such a case, the reactor would automatically come to a halt within a few seconds, since the process of energy production is arrested, with no effects taking place on the outside. For this reason, fusion reactors are considered to be inherently safe.

Top 15 Most Important and Expected Questions on Nuclei in Hindi.

Frequently Asked Questions – FAQs


What is Nuclear Fusion?

Nuclear fusion is a reaction through which two or more light nuclei collide to form a heavier nucleus.

What is the life span of a nuclear power station?

The usual life span of a nuclear power station is 40 years. But the modern pressurised water reactors come with a life span of 60 years.


How are nuclear accidents classified?

According to the International Atomic Energy Agency (IAEA), two sub-levels categorise accidents. The main two levels are the upper level with 4-7 sub-levels and the lower level with 1-3 sub-levels.


Name the international organisation that oversees the operation of nuclear power stations.

The International Atomic Energy Agency (IAEA) is an international organisation that oversees the operation of nuclear power stations. This organization provides guidelines and frameworks on how nuclear power stations need to be operated.


Can we say that nuclear energy is a highly productive source of power?

Yes, we can say that nuclear energy is a highly productive energy source as a massive amount of energy is produced by triggering one neutron. Also, nuclear power stations are unaffected by seasonal conditions.


What is nuclear fission?

Nuclear fission is a nuclear reaction that splits a heavy atom into multiple smaller ones.

Write some benefits of nuclear energy.

Nuclear energy is used in various industrial applications, such as hydrogen production, seawater desalination, the extraction of tertiary oil resources, district heating, and cooling.

Write some advantages of nuclear fusion.

Following are the advantages of nuclear fusion:
  • It is a safe source for the generation of electricity.
  • It is economical and sustainable.
  • The amount of fuel available in nature is abundant and inexpensive.
  • The greenhouse gases produced during the process of fusion are minimal.

Define nuclear binding energy.

Nuclear binding energy is defined as the energy required to split the nucleus of an atom into its components.

What is nuclear physics?

Nuclear Physics is defined as the branch of physics that deals with the structure of the atomic nucleus and its interactions.

What is radioactivity?

Radioactivity is a nuclear process that occurs due to the decay of the nucleus. Radioactivity is based on the law of conservation of charge. External parameters such as temperature and pressure do not affect the rate of decay.

What are the types of nuclear reactions?

The following are the types of nuclear reactions:
  • Nuclear Fission
  • Nuclear Fusion
  • Nuclear Decay
  • Transmutation

Nuclear reactors use which type of reaction to generate electricity?

Nuclear reactors use nuclear fission reactions to generate electricity.

What are nuclear scattering processes?

Nuclear scattering processes are the processes that involve the collision and subsequent separation of atomic nuclei without any notable changes in the nuclear composition. In these processes, only momentum and energy are transferred.

What is nuclear binding energy?

Nuclear binding energy can be defined as the energy required to hold all the protons and neutrons within the nucleus.

Stay tuned with BYJU’S to learn more about nuclear fusion, energy, and much more.

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