Nuclear Energy - Pros and Cons

The sun, stars and wind are seemingly inexhaustible sources of energy. Basically, there are two types of energy sources:

• Conventional Energy Sources
• Non-conventional Energy Sources

While coal, petroleum etc are the conventional sources of energy, various other sources of energy such as atomic energy or nuclear energy are also becoming popular these days. Nuclear energy is the prospect of future and there is a lot of research work going on in this field these days.

Nuclear energy is the form of energy in which matter is converted to energy by the means of sustained nuclear fission to generate heat and electricity. Scientists have been able to harness that mechanism and successfully use it to generate power. Presently, nuclear energy provides for approximately 16% of the world's electricity and about 6% of the world's energy. The nuclear reactors that we have today work on the principle of nuclear fission. Around the world, there are thousands of scientists working daily for finding out some more ways to harness nuclear energy more efficiently and effectively.

Nuclear energy can be produced naturally or through manmade operations in a controlled manner:

• Naturally: Nuclear energy can be produced naturally, like sun and stars making heat and light energy.
• Man-Made: Nuclear energy can be man-made too through the process of controlled nuclear reactions under favourable conditions. Machines called nuclear reactors, parts of nuclear power plants, provide electricity for many cities and are being used efficiently. Man-made nuclear reactions also occur in the explosion of atomic and hydrogen bombs. Further man-made nuclear energy can be created in two different ways that are Nuclear Fission and Nuclear Fusion.

Nuclear Fission: Nuclear fission is the process in which the atoms of nuclei split thus causing energy to be released. Some destructive process like the atomic bomb also works by nuclear fission. The element uranium is the main fuel used to undergo nuclear fission to produce energy since it has many favourable properties. Uranium nuclei can be easily split by shooting neutrons at them. Also, once a uranium nucleus is split, multiple neutrons are released which are used to split other uranium nuclei. This phenomenon is known as a chain reaction. 
Fission is a form of nuclear transmutation because the resulting fragments are not having the properties same as that of the atom. The two nuclei produced as a result of nuclear fission are most often of comparable but slightly different sizes, typically with a mass ratio of products of about 3 to 2, for common fissile isotopes. Most fission reactions are binary fissions producing two charged fragments, but occasionally 2 to 4 times per 1000 events, three positively charged fragments are produced, in a ternary fission. The smallest of these fragments in ternary processes range in size from a proton to an argon nucleus. Nuclear fission can also occur effectively without neutron bombardment, as a type of radioactive decay. This type of fission is called spontaneous fission and is very rare except in a few heavy isotopes. In various nuclear devices, particularly all nuclear fission occurs as a whole nuclear reaction which is a bombardment-driven process that results from the collision of only two subatomic particles and may be a dangerous process. Nuclear reactions are thus driven by the mechanics of bombardment. Many types of nuclear reactions are currently known and being used.
Nuclear fission differs importantly from other types of nuclear reactions, in that it can be amplified and sometimes be controlled by a nuclear chain reaction (one type of general chain reaction). In such a reaction, free neutrons released by each fission event can trigger yet more events, which in turn release more neutrons and cause more fission. This may also lead to an explosion. The most common fission process is binary fission and produces two fission products. Another type is ternary fission in which three products are formed but ternary is less common.

Nuclear Fusion: Nuclear fusion is the process by which the nuclei of atoms are joined together or fused together by colliding them with each other at very high speed. This happens only under very hot conditions that are specially created for reaction to take place. Nuclear fission is the source of the energy of the Sun like all other stars. The nuclear fusion reaction in sun takes place when hydrogen nuclei fuse to make helium. The hydrogen bomb, which is the most powerful and destructive weapon, also works by the principle of nuclear fusion. The heat required to start the fusion reaction is so great that an atomic bomb is used to provide it and this type of reaction is carried out very carefully and by expert research scholars only. In nuclear fusion reaction hydrogen nuclei are fused to form helium and in the process release huge amounts of energy thus producing a huge explosion which is carried out under the controlled environment. During the process of nuclear fusion, the matter is not conserved because some of the mass of the fusing nuclei is converted to photons which are released through a cycle. Fusion reaction of light elements is the source of power of the stars and produces virtually all elements in a process called nucleosynthesis. The fusion of two nuclei with relatively lower atomic masses than iron generally releases energy, while the fusion of nuclei heavier than iron leads to absorption of energy. The opposite is true for the reverse process, nuclear fission, fusion process generally occurs for lighter elements only, and on the other hand, fission normally occurs only for heavier elements.

Nuclear Power

Nuclear power plants are the scope of future. Today there are a lot of non-conventional energy sources being explored by the scientist. Nuclear power is also one of them. As day by day demand for energy is increasing, the energy sources are also being depleted side by side; hence a day will come when all the conventional sources would be extinguished. In order to avoid such situation, it is better to find out some non-conventional sources of energy and develop them well in advance to reduce some burden of conventional sources so that they are not depleted. Just as the conventional thermal power stations generate electricity by harnessing the thermal energy released by the burning of fossil fuels like coal, petroleum etc, nuclear power plants make use of the energy released from the nucleus of an atom by the process of nuclear fission that takes place in a nuclear reactor under a controlled reaction. The heat is removed from the reactor core by a cooling system that uses the heat to generate steam, which drives a steam turbine connected to a generator hence producing electricity.

Nuclear Energy- Advantages and Disadvantages

There is no perfect energy source which produces energy without any complication related to it. Each and every process one has its own advantages and compromises related to their energy production process or in the form of byproducts which are being produced. Nuclear power is a sustainable energy source that reduces carbon emissions and increases energy security by decreasing dependence on imported energy sources. Nuclear energy comes with a great advantage of producing energy without any pollution and resource depletion, but it has disadvantages too. The nuclear power debate concerns the controversy that surrounds the deployment and using of nuclear fission reactors in order to generate electricity from nuclear fuel for civilian purposes. Nuclear power poses many threats to people as well as the environment. These threats include the problems are due to radioactive material being used in these plants and concern mostly the processing, transport and storage of radioactive nuclear waste, the risk of nuclear weapons proliferation and terrorism. There are also some serious health risks as well as environmental damage related to uranium mining which is carried out for nuclear power production process. Nuclear reactors themselves are enormously complex machines where if anything goes slightly out of order can lead to some serious accidents which humans have experienced earlier and are very dangerous for mankind.

Advantages of Nuclear Energy

• The Earth has limited supplies of conventional energy sources like coal petroleum etc. Nuclear power plants can produce electricity without these sources like coal and oil and help in lowering their consumption.
• Very small amount of raw material is required. Nuclear power plants need less fuel than ones which burn fossil fuels. One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil.
• Nuclear power is an absolutely clean form of energy; it does not result in any emission of toxic gases like carbon dioxide, nitrogen dioxide or sulfur dioxide.  Coal and oil burning plants pollute the air. Well-operated nuclear power plants do not release any kind of contaminants into the environment. Air pollution these days is one of our main concerns about our environment. Hence an option like a nuclear plant is certainly preferable over the combustion of conventional fossil fuels which causes much more pollution and produce less energy.
• The important aspect of energy production in a nuclear plant is related to the management of the waste products. Nuclear waste that results from the generation of nuclear power is much easier to manage as compared to those related to some conventional power process. Since the nuclear waste is dumped in a proper geological position, where it decays over a period of time thus it has no negative impact on our ecosystem. This proves to be one of the greatest advantages of nuclear power compared to the conventional power production process that produces chemical waste, such as arsenic or mercury, that refuses to dissipate, or toxic gases thus causing global warming, acid rain and smog which possess a great threat for our environment.
• A yet another major benefit of nuclear energy is that it is an extremely reliable source of energy since most of the nuclear reactors come with a lifespan of 40 years, which can easily be extended again for 20 years.  Hence reliability is an added advantage.
• The availability of nuclear power has quickly gained competitive with other energy sources such as oil and gas because of economic reason, as the cost of nuclear fuel is a small part of the overall reaction, so even if there is a fluctuation in the cost of material in the market the reaction would not be affected much.
• A great fear associated with nuclear energy in the mind of people is the fear of radiation. People actually don’t know that the radiation was part of our environment, since its existence, and that the radiation in proper amounts can even be very beneficial to our health. Hence radiation is not something from which we need to fear but can be channelled appropriately to serve humanity in a positive and a proper way.  
• Nuclear power stations are usually very compact compared to thermal stations.
• Its maintenance cost is very low.
• Also, the transportation of material can also be very easy since these are required in very small quantity unless we consider security.

Disadvantages of Nuclear Energy

• Safety issues associated with nuclear power are hard to be overlooked.
• The initial set-up cost is very high because of complex radiation containment systems and procedures
• Great risk of accident in the form of nuclear explosion or fuel leakage
• Time involved in the construction of these power plants is very large
• Threat from terrorism
• Uranium sources which are most importantly needed are just as finite as other fuel sources, such as coal, natural gas, etc., and also slightly expensive to mine, refine, and transport, and produce considerable environmental waste during all of these processes.
• Nuclear waste takes at least 200 thousand years to degrade.
• The proliferation of nuclear technology increases the risk of nuclear war too. 
• Shipping nuclear waste internationally is expensive considering security also and, poses an increased potential threat of terrorism.