Fission and Fusion Reactions

Nuclear fission and fusion reactions are two distinct chemical processes that manipulate the nucleus of radioactive materials to either decrease their atomic number or increase it. This happens because both fusion and fission processes release enormous amounts of energy that humans can use to meet the ever-rising demand for power in the world.

Even if nuclear fusion produces massive and clean energy, it is yet to become feasible. This is because the safety units and reactors to successfully control and use energy from this reaction are still under development. Currently, the energy industry uses nuclear fission to supply energy but only to some extent due to issues such as health hazards, risks, and old technology. In this study material, we will look at the causes and implications of Fission and Fusion Reactions.

Nuclear Fission

It is a process in which the large unstable heavy nucleus breaks into two smaller and lighter nuclei and releases neutrons along with massive amounts of energy in the form of heat. Nuclear fission can occur in two different methods: spontaneously or naturally and induced or forced. Spontaneous reactions occur in some radioactive elements like californium-252 naturally.

In nuclear fission, a fast-moving neutron strikes the heavy nucleus of radioactive elements like uranium-235, making the nucleus unstable until it breaks up into two lighter nuclei releasing enormous energy. This also releases some fast-moving neutrons, creating a chain reaction. The by-products of these reactions are free neutrons in gamma rays and other nuclear fragments, making them a source of free neutrons in an induced nuclear fission process. The response during the process of fission is as follows:

235U + 1n → 141Ba + 92Kr + 3 n

In most cases, the lighter elements formed are unstable and undergo nuclear decay to transform into stable features. To understand this better, here is an example of the nuclear fission of Uranium-235. Uranium-235 is a radioactive element with 92 protons and 143 neutrons. The element on its own is a little unstable, and the nucleus can split up if there is any stimulation from an external source.

When the element sample accepts the fast-moving neutron, it disintegrates into two lighter elements and again releases 2 to 4 free, fast-moving neutrons. This process is exothermic by nature, meaning that it can release heat. This process results in substation levels of usable energy. This energy is changeable into various other forms as needed by humans.

Hazards that come with Nuclear Fission

The nuclear disasters happening across the globe are proof that nuclear sources of energy are not safe or sustainable. The cause of these disasters is not always a mistake made by the people but rather due to natural influences. The resulting waste material is radioactive and dangerous for both the environment and human life.

This radiation from the toxic waste damages the human body, making it a highly dangerous by-product that requires proper treatment before releasing it into the outside world. Those waste products that reach the environment without adequate treatment can cause radiation, skin burns, skin diseases, and long-term terminal disorders like cancer and heart problems.

Nuclear Fusion

Nuclear fusion refers to fusion between two lighter nuclei into a heavier nucleus which releases massive amounts of energy, more than nuclear fission. This process needs high amounts of energy as it can happen only when the two nuclei are in the state of plasma or highly charged with enough power to overcome the nuclear attraction forces within the nucleus to merge with the nucleons of the other nucleus.

The highly charged plasma contains positive ions and free electrons in a state beyond the three states of matter. This has enough energy to overcome the repulsion forces in play and come close enough to each other that the nuclear attraction force overpowers the repulsions and combines the nucleons or fuses them. Enclosing the nucleons in a small space ensures fusion as the collision rates are high.

The amount of energy released by this process is very high and almost fourfold the energy by nuclear fission. This is the same process that occurs in the sun and continues for millions of years in the form of chain reactions. There is a sufficiently high temperature in the sun to convert the nuclei of its constituent elements into the plasma state. The pressure of the gravitational pull ensures the occurrence of collisions creating suitable conditions for nuclear fusion. The reaction on the sun in nuclear fusion is:

5 2D + energy →  4He + 2n0 + 3He + P+ + energy;

The initial process needs enormous energy to achieve the plasma state of matter in the nucleus. Between nuclear Fission and Fusion Reactions, the latter creates excessive waste products that cannot be used or recycled. Once the raw material reaches this state, the resulting energy after fusion is much more than the input. This is a cleaner form of nuclear energy production with higher outputs as the by-products of this reaction do not include any type of radioactive element.

But instead, the by-products are harmless alpha particles and neutrons. The neutrons may create radioactive isotopes in the reaction chamber, but most of them have very small half-lives, and this process does not need geological storage of toxic wastes like nuclear fission.

Why is Nuclear Fusion not Employable?

Among both Fission and Fusion Reactions, even with the many benefits, nuclear fusion needs high inputs such as extremely high temperatures and pressures for fusion. Additionally, there is a need for a confinement chamber that satisfies these requirements and holds on to the plasma long enough to make enough power to cross the target energy threshold to produce enough energy to recover the energy input.

Conclusion

Nuclear fission and fusion reactions are two processes used to produce energy, but only one is feasible with the current technology. Nuclear fission requires input in radioactive elements, while nuclear fusion is much cleaner and uses elements like deuterium and tritium to produce massive energy. Although nuclear fusion is not usable or deployable, scientists are working towards progress in this aspect to create power generation plants that generate energy from nuclear fusion and supply a cleaner and more efficient energy source.