Many countries are keen to harness nuclear power in their own countries. The world’s most powerful nations continue to operate nuclear power plants, despite the dangers of the technology and the environmental harm it may cause. This is because the world is getting ready to cope effectively with the potential energy crisis that lies ahead. The scarcity of fossil fuels has necessitated the adoption of alternative energy sources. Another factor for nuclear power generation in a massive nuclear plant is the tremendous efficiency of the nuclear fuel used to harness nuclear fission power and its availability.
A tiny cubic centimeter of nuclear fuel can produce more power than 500 liters of crude oil can do. A nuclear plant can generate nuclear power in two ways. Nuclear fission and fusion; Nuclear fission is, by far, the only feasible way of producing nuclear power in the entire world. Nuclear fusion is the other approach. This technique is not currently in use owing to a practical issue that emerged during its initial implementation. Scientists have been working relentlessly for years to discover a solution. Regrettably, no practical solution has yet been discovered. Let’s explore what nuclear fission is, how it produces energy and other pertinent facts. But first, you must grasp the fundamental differences between a chemical reaction and a nuclear reaction.
Difference Between A Chemical And A Nuclear Reaction
- The main difference between a chemical reaction and a nuclear reaction is that a chemical reaction only involves the electrons in an atom (it takes place outside of the nucleus). In contrast, a nuclear reaction involves the decomposition of an atom’s nucleus (occurs exclusively within a nucleus).
- The reactants and products have the same mass in a chemical reaction, but the mass of reactants and products change in a nuclear reaction.
- A nuclear reaction produces a massive amount of heat, whereas a chemical reaction produces less heat than a nuclear reaction.
What Is Nuclear Fission?
An atomic nucleus splits up into numerous smaller atomic nuclei during a nuclear fission reaction. As we mentioned above, there is a destruction of mass. Fission energy is derived through the heat released from mass destruction.
Uranium-235 is the nuclear fuel that is used to produce energy in nuclear fission using nuclear reactors. This uranium is a fairly common element found on the Earth’s surface. Uranium reserves are prevalent in Australia, Kazakhstan, Canada, South Africa, Russia, China, and several other countries. Uranium mined from Uranium reserves cannot be utilized directly in the nuclear fission process. It is essential to separate the Uranium-235 isotope from the uranium obtained.
How Is Uranium-235 Isotope Separated From Uranium?
Uranium mined from uranium ore reserves is pulverized and chemically treated to eliminate organic pollutants during the Milling process. After removing organic pollutants, the Acid Leaching procedure is carried out by adding sulfuric acid to uranium. The Acid Leaching procedure results in the formation of uranium oxide (The isolated form of uranium). It comes in the form of a yellow powder and is widely known as Yellowcake. The uranium-235 isotope makes up only 0.7% of the total, while the uranium-238 isotope accounts for the remaining 99.3%.
We use centrifugal force to separate two such isotopes. Isotope separation is performed using special equipment called a Gas Centrifuge. The difference in mass between uranium-238 and uranium-235 is just approximately 1%. Therefore, the separating process is complex.
Uranium Oxide (Yellowcake) must be converted to a gaseous state to overcome this complexity. Following that, uranium oxide is chemically mixed with hydrogen fluoride and fluorine gas to produce uranium hexafluoride. Uranium hexafluoride is placed into a rotating cylinder and spun at high speed in order to separate the uranium-235 isotope.
As the cylinders filled with uranium hexafluoride spin faster (Usually 50000-70000 rpm), heavier uranium-238 accumulates on the outside, and lighter uranium-235 accumulates middle of the cylinders. Uranium-235, which has been slightly enriched, is propelled to the next phase. The enrichment stage is comprised of thousands of centrifuges running simultaneously, like a cascade. This process is called uranium enrichment. If the uranium-235 concentration is between 5% and 20%, it can be utilized as a nuclear fuel to generate electricity. When uranium-235 is enriched to a purity of up to 90%, it is referred to as weapon-grade uranium. They are utilized in the manufacturing of nuclear weapons.
This is the primary reason why everyone is keeping tabs on Iran uranium enrichment. They are only permitted to enrich uranium to a purity of 3.67%. They have consistently violated the Iran nuclear deal by enriching uranium with more than 20% of purity.
Nuclear Fuel Assembly
Enriched uranium hexafluoride is combined with calcium to produce tiny cylindrical pellets out of uranium dioxide powder. These are deposited inside the metal tubes of nuclear fission reactors located in nuclear power plants. Each reactor vessel often includes hundreds of fuel assemblies, also known as fuel elements or fuel bundles. Each of the fuel assemblies has around 200 fuel rods. Control rods fixed inside these tubes can control the level of neutrons that flow through them. This is how nuclear reactors manage the pace of the nuclear reaction.
How Does Nuclear Fission Produce Energy?
When a fast-moving neuron attacks this Uranium-235 nucleus, it splits into two nuclei: krypton and barium. During this nuclear fission, three additional neutrons are released. They have the ability to break down other uranium-235 nuclei. As this is a continual process, we call it a chain reaction. An enormous amount of heat is emitted during this process. The heat produced is then utilized to boil water into high-pressure steam, which is subsequently used to spin turbines linked to a generator. This is how nuclear fission energy is harnessed. Nuclear fuel is generally utilized in the reactors for a period of three to five years.
Nuclear power plant effluent is highly radioactive. When spent fuel is withdrawn from nuclear reactors, it is stored underwater to provide cooling and a protective coating for radioactive effluents. Dry cask storage can be utilized to store such high-level nuclear waste after cooling in the spent fuel pool for roughly ten years. Or they can be stored in steel containers, sealed, and disposed of deep underground.
- The primary nuclear fuel that is being used around the world in the present is the Uranium-235 isotope.
- In combination with a fissile material such as recycled plutonium, thorium can be utilized as an alternative fuel to generate nuclear power. However, particular types of nuclear reactors such as Molten Salt Reactors (MSRs) will be required.
- Before the acid leaching process, mined uranium is crushed and chemically treated. The end product of the acid leaching process is uranium oxide, popularly known as Yellowcake.
- A gas centrifuge separates the Uranium-235 isotope, which is subsequently enriched to a purity of 3% to 5%.
- Enriched uranium hexafluoride is chemically treated to produce uranium dioxide powder, which is used to fabricate nuclear fuel.
- A tremendous amount of energy as heat is released during nuclear fission processes in nuclear reactors, which are utilized to generate low-carbon electricity.
- High-level radioactive waste, such as spent nuclear fuel, is either kept underwater, in dry casks, or buried deep underground.