Nuclear fusion and fission are two terms that might sound similar, but are actually pretty different in meaning. To avoid any instances where you use the two terms interchangeably, in this post, we learn all about nuclear fusion vs fission.
Nuclear Fusion vs Fission: Understanding the Terms
What is Nuclear Fusion: Nuclear Fusion Definition
When it comes to the nuclear fusion definition, it creates energy by coalescing atomic nuclei instead of disintegrating them (similar to fission). No harmful, long-term radioactive waste or greenhouse gases are produced during this process, occurring naturally in the stars’ centres like the Sun.
Like fission power plants, nuclear fusion plants use heat from atomic reactions to heat water, produce steam, power turbines, and generate electricity. However, it has proven difficult to create the necessary conditions in fusion reactors without using more energy than is generated. A fusion reactor, also known as a tokamak, uses a gas, typically deuterium, an isotope of hydrogen that can be extracted from seawater. High heat and pressure cause the deuterium atoms’ electrons to break free, forming a plasma. Strong magnetic fields are required to contain this plasma because it can reach temperatures of at least 100,000,000°C. Plasma is a superheated, ionised gas. Although these temperatures are ten times higher than those at the Sun’s core, they are necessary for the process because the gravitational pressure needed for it cannot be produced by the Sun itself.
As auxiliary heating systems raise the temperature to the necessary levels for nuclear fusion (150-300 million °C), the energised plasma particles collide and heat up. The highly energetic particles can overcome their inherent electromagnetic repulsion when they collide, fusing them and releasing enormous amounts of energy.
What is Nuclear Fission: Nuclear fission definition
According to the nuclear fission definition by scientists globally, atoms are torn apart during nuclear fission to release the nuclear energy that holds them together. A nuclear power plant uses the heat from boiling water into steam to move a turbine and power generators to generate electricity. This energy is discharged as heat and radiation. There are no carbon emissions when uranium is used in this technique instead of fossil fuels to generate heat.
In a steel reactor vessel, sealed metal cylinders containing uranium are used to split atoms in power plants. The uranium atoms are bombarded with neutrons, which cause them to split and release additional neutrons that strike other atoms, setting off a chain reaction that further splits atoms and releases energy from heat and radiation.
Nuclear fusion vs fission
Now, we learn about the nuclear fusion-fission difference. Speaking of the nuclear fusion vs fission difference, nuclear fusion and fission are chain reactions in which one nuclear event triggers at least one further nuclear reaction, and the chain reaction often goes on indefinitely. The outcome is an expanding chain of reactions that can soon spiral out of control. This nuclear reaction can merge light isotopes like 2H and 3H or numerous splits of heavier isotopes like uranium 235U. Fission chain reactions only start when neutrons break unstable isotopes. Although controlling or bearing this kind of impact and scatter process is challenging, setting up the basic conditions is rather simple.
On the other hand, the fusion chain reaction only develops or occurs in extremely high-pressure and temperature environments maintained by the energy released during the nuclear fusion process. Additionally, we found that the stabilising fields and initial conditions are very challenging to implement with our current technology, suggesting that Physics needs sophisticated technology to carry out this revolutionary process.
There is a huge difference between the nuclear fusion vs fission energy outputs too, as both processes release energy using different methods.
Energy is released from nuclear fusion reactions 3–4 times faster than fission. Although there are no fusion systems on Earth, the Sun’s output is characteristic of fusion energy generation since it continuously transforms hydrogen isotopes into helium while releasing a range of heat and light spectra. Fission produces energy by dissolving the strongest nuclear force and releasing a massive amount of heat that is then utilised to heat water (in a reactor) and produce energy (electricity).
Nuclear fusion defeats the strong and weak nuclear forces, producing energy that can be used to power a generator. As a result, more energy is liberated and can be used more directly.
Nuclear events like nuclear fusion and fission are chain reactions, which means that one nuclear event normally triggers at least one further nuclear reaction. The end outcome is an expanding loop of reactions that can easily spiral out of control. Multiple splits of heavy isotopes, like 235 U, or the merging of light isotopes can occur in this kind of nuclear process (e.g. 2H and 3H).
When neutrons bombard unstable isotopes, fission chain events take place. Although the beginning circumstances for this kind of “hit and dispersion” process are very easy to produce, controlling it can be challenging. A nuclear fusion chain reaction can only happen under extreme conditions of pressure and temperature, which are maintained by the energy released during the fusion process.
Nuclear energy is feared because of its extreme uses as a weapon and a power source. The waste produced by a reactor’s fission is intrinsically harmful (see more below) and might be used to make dirty bombs.
Even though nuclear energy is significantly safer than fossil fuels, many people are hesitant to accept it, although some countries, like Germany and France, have excellent records with their nuclear facilities.
Other less positive examples, like those seen in Three Mile Island, Chornobyl, and Fukushima, have made this decision. If the extreme conditions required for nuclear fusion creation and management can be overcome, fusion reactors may one day provide the cheap, abundant energy required.
Nuclear Fusion vs Fission: Uses of Nuclear Fusion and Fission
It is common knowledge that the building blocks of matter, such as atoms, are electrons, protons, and neutrons. The centre of the atom contains protons and neutrons, and the electrons are organised and surround it in their valence shells. The chemical characteristics of an atom or the characteristics of the element they belong to are determined by the number of neutrons and protons in the atom. Despite the nuclear fusion-fission difference, both processes have provided mankind advantageous uses.
A potent nuclear force acting very close to one another holds all of these atomic particles together. The energy contained in an atom changes when electrons change their valence shell, as is seen. The process by which an electron moves from the outer to the inner valence shells involves the absorption of energy. On the other hand, an electron releases energy when it moves from the inner to the outer shell.
According to a general principle, the energy released is enormous compared to other energy we utilise for daily activities. Following the revelation of this fact, numerous scientists created a technique for obtaining and using the enormous amount of energy obtained through this technique.
A type of an element’s atom with variable numbers of protons and electrons but the same number of neutrons is called an isotope. It is relatively simple to separate the electrons and protons from the energy holding them in place in these kinds of atoms. Nuclear fission is dividing an atom into two pieces to generate energy.
In contrast, it occurs when two atoms join, releasing energy. Nuclear fusion is the name given to this process of producing energy. The Sun and other stars release energy in this manner. These brilliant celestial bodies are formed when two hydrogen atoms combine to generate helium atoms.
Nuclear Fusion vs Fission: Conclusion
Weak and strong nuclear bonds are the two primary natural forces that hold atoms together. The total energy stored within the atomic bonds is known as the binding energy. The more stable the atom is, the more binding energy is stored within the bonds. Atoms make a further effort to increase stability by raising their binding energy.
Fission reactions can spiral out of control and either explode or cause the reactor producing them to melt down, creating a huge pile of radioactive slag. Every minute the reaction lasts, such explosions or meltdowns contaminate the environment by releasing tonnes of radioactive particles into the air and any nearby surface (land or water). A nuclear fusion reaction that goes out of balance and loses control, on the other hand, slows down and drops in temperature until it stops.
The burning of hydrogen into helium causes stars to lose these elements over thousands of years of expulsion, which is what happens to stars. Few radioactive byproducts of nuclear fusion are produced. If there is any damage, it will mostly affect the area right around the fusion reactor.
Fission is still used to produce energy even though fusion is much safer because it takes less energy to split two atoms than fusing two. Additionally, the technical difficulties associated with managing fusion reactions still need to be resolved. Both nuclear fusion and fission have their own shortcomings and advantages due to which the scientific world makes good use of both processes.
We do hope this article clarifies nuclear fusion vs fission for you! For further information on the nuclear fusion definition, nuclear fission definition, or the nuclear fusion-fission difference, you can give this video a watch!