What is Nuclear Fusion?
The process in which the nuclei of two light atoms combine to form a new nucleus is known as nuclear fusion. It is the process that powers the sun and the stars and is the ultimate energy source for the future of mankind as it is another way of producing nuclear energy like nuclear fission.
The combination of Deuterium and Tritium, the two isotopes of Hydrogen to give Helium and releasing a neutron and giving out around 17 MeV of energy is an example of a nuclear fusion.
Nuclear Fusion reactions occur when two or more nuclei of the atom come close enough up to the extent that the nuclear force pulling them together exceeds the electrostatic force that pushes them apart, fusing them into heavier nuclei. For nuclei lighter than iron-56 the reaction is exothermic, thus releasing energy while for nuclei heavier than iron-56, the reaction is endothermic, thus requiring energy.
Therefore we can say that nuclei smaller than iron-56 are more likely to fuse while those heavier than iron-56 are more likely to break apart.
Nuclear Binding Energy and Nuclear Fusion
When two lighter nuclei undergo a fusion reaction, the combination has a mass that is less than the mass of the initial individual nuclei. This difference in the mass between the reactants and products is compensated by either the release or absorption of energy known as binding energy between the atomic nuclei before and after the reaction.
Einstein’s mass-energy equivalence explains the energy that the reaction gives out energy during Fusion.
Applications of Nuclear Fusion
One of the main uses of nuclear fusion is that of generating electricity. Fusion power makes use of heat that is generated from nuclear fusion reactions to produce electricity with the help of a device called a thermonuclear reactor. In this process, two atomic nuclei that are considerably lighter, are combined to form a heavier nuclear, while releasing energy.
It is a very safe, environmentally friendly, and clean source of energy that creates way less waste than the process of nuclear fission does.
Types of Fusion Reactors
There are several approaches to control and contain a fusion reaction to exist, but the two primary approaches based on confinement are the concept of magnetic confinement and inertial confinement.
Magnetic confinement fusion (MCF) reactors are the more advanced of the two approaches, as and in this they utilise magnetic fields generated by electromagnetic coils to confine a fusion plasma in a donut-shaped (torus) vessel.
Unlike magnetic confinement approaches, inertial confinement fusion (ICF) approaches attempt to externally heat and compress fusion fuel targets to achieve the very high temperatures and even higher densities required to initiate nuclear fusion.
For most ICF concepts and approaches, high power lasers are used to compress and heat the fuel.
Recently, a third approach, which exploits the parameter space between the conditions produced and needed for magnetic and inertial confinement has gained traction in recent years and is receiving much scientific, and even commercial, attention. This is called Magnetised target fusion (MTF), sometimes known as magnetized inertial fusion (MIF), it looks to exploit the use of higher density plasmas than for MCF approaches, but lower power lasers and other drivers than those used in ICF approaches. MTF offers a unique route to fusion, and the accelerated development of several unique concepts has seen significant support.
Components of Magnetic Confinement Reactors
Vacuum vessels are used to hold the plasma and to keep the reaction chamber in a vacuum.
A neutral beam injector is used to inject particle beams from the accelerator into the plasma thus heating the plasma to its critical temperature.
Magnetic field coils are used in magnetic fields, and the plasma is confined in the superconducting magnets.
A central solenoid is used to provide electricity to the magnetic field coils.
Cooling equipment is used to cool down the magnets.
Blanket modules: These are generally used to absorb heat and high-energy neutrons from the fusion reaction.
Diverters: They are used to exhaust helium products.
Advantages of Nuclear Fusion
Fusion is capable of powering the whole world at a very low cost since there is virtually limitless fuel available that can be used to make electricity. There is a lot of energy released in fusion rather than fission, therefore it would be more profitable if it is set up. Also when producing nuclear fusion energy, there is hardly any waste. As a result of this, there would be no money wasted in disposing and clearing of the wastes produced by the reaction.
Thus, Fusion is capable of powering the entire world at a much low cost, as compared to power sources used nowadays. It is a clean energy source that means no greenhouse gases and emitting only helium as exhaust. It is easier to stop nuclear fusion reactions as compared to fission reactions since there is no chain reaction in fusion.
Disadvantages of Nuclear Fusion
It would be very expensive to build a power plant to produce energy because Nuclear fusion can only occur between 14999726.85 degree celsius to 9999726.85 degree Celsius. (Or 10-15 million kelvin) Thus, there are no materials that can cope with 10-15 million K and also since it is a non-renewable energy. There can also be radioactive wastes.
Interesting Facts about Nuclear Energy
Nuclear energy is derived from uranium which is a non-renewable resource that we get from mining.
In the 1930s, a scientist named Hans Bethe discovered the possibility of nuclear fusion and how it was an energy source for the sun.
The energy generated from the process of nuclear fusion is abundant in supply, limitless even.
The largest successful nuclear reactor is at the Culham Science Centre in Oxford.
FAQs on Nuclear Fusion Reactors
1. List Some Effects of Fusion on the Environment?
Fusion is one of the most environmentally friendly sources of energy and also there is no CO2 or other harmful atmospheric emissions during the process of the fusion, this means that fusion does not contribute to greenhouse gas emissions or global warming. The two sources of fuel of fusion, hydrogen and lithium, are widely available in many parts of the Earth.
2. What is the Point of difference and Similarity between Nuclear Fission and Nuclear Fusion?
Both nuclear fusion and fission are nuclear processes as they both involve nuclear forces to change the nucleus of atoms. The fission nucleus of heavy element splits (with a high atomic mass number) into fragments; while fusion nucleus of two lighter elements joins (with a low atomic mass number), forming a heavier element.
In both cases, energy is freed because the mass of the remaining nucleus is smaller than the mass of the reacting nuclei and why the opposite processes release energy can be understood by examining the binding energy per nucleon curve.
3. Does the Fusion Process Produce Radioactive Nuclear Waste the Same Way Fission does?
Nuclear fission power plants have the disadvantage of generating unstable nuclei; some of these are radioactive for millions of years while fusion on the other hand does not create any long-lived radioactive nuclear waste.
A fusion reactor mainly produces helium, which is an inert gas. It also produces tritium which is consumed within the plant in a closed circuit.
4. What is nuclear fusion? How does nuclear fusion affect the environment?
The reaction in which two or more atomic nuclei are combined to form either one or more different types of atomic nuclei along with subatomic particles such as neutrons and protons is referred to as nuclear fusion.
Fusion is considered to be one of the most environmentally friendly sources of energy. This is mainly because, during the process of fusion, there are no kinds of harmful atmospheric emissions, like that of CO2. As a result, the process of fusion does not create any sort of greenhouse gases, and neither does it contribute to the dangerous phenomenon of global warming.
5. Can nuclear fusion lead to a nuclear accident?
No, the process of nuclear fusion cannot cause a nuclear accident. This is because, unlike nuclear fission, the production of fusion energy is not based on a chain reaction. With the support of external heating systems, plasma must be kept at a very high temperature and should be confined with the help of a magnetic field, but external. With every possible shift or change of the working configuration in the reactor, either the cooling of plasma takes place or its loss of containment.
In such a situation, wherein the process of energy production has stopped, within just a few seconds, the reactor would come to a halt on its own with no effects taking place on the outside. And it is for this precise reason that nuclear fusion reactors are considered to be extremely safe.
6. Does the process of fusion produce any nuclear waste?
Unlike the process of nuclear fission, fusion does not produce any radioactive nuclear waste that exists for a very long time. It does, however, produce an inert gas (helium), and also produces as well as consumes tritium. And although tritium is radioactive, its half-life is relatively much shorter. Besides, it is only used in small amounts, thereby rendering it incapable of causing any serious harm or danger.
7. What is the difference between nuclear fusion and fission?
The difference between nuclear fusion and nuclear fission is as follows:
Nuclear Fusion | Nuclear Fission |
This nuclear reaction tends to take place when two atoms are combined to get one or more different atomic nuclei as well as subatomic particles. | This nuclear reaction is one wherein the nucleus of an atom is bombarded with neutrons that have low energy, which further split the nucleus into smaller nuclei. |
Such reactions generally occur in the sun and the stars. | Such reactions don’t usually occur in nature. |
An immense amount of energy is required to combine two or more atoms in a fusion reaction. | Relatively little energy is required to split an atom in a fission reaction. |
A hydrogen bomb tends to work on the principle of fusion reaction. | An atomic bomb tends to work on the principle of the fission reaction. |
8. Explain the types of fusion reactions.
There are generally two main types of fusion reactions. They are as follows:
Fusion reactions tend to preserve the number of protons as well as neutrons. These types of reactions are paramount to practical energy production.
Fusion reactions tend to involve conversion between protons and neutrons. These types of reactions are vital to the initiation of the burning of stars. You can learn more about Nuclear Fusion reactors in Vedantu. You will get different study materials on the Vedantu website and app which will help you to understand this topic better.