The pattern that one must consume fuels and dirtily provide energy and power has failed. Applying it has caused and it cannot solve the increasing world energy crisis. Most energy is presently obtained by “dirty methods”. Hence as energy production increases so do harmful combustion of by products. And if this method is continue to be used, by 2030 the combination of these factors will increasingly spread worldwide economic and biosphere chaos. The production in which uses the pattern that produces energy and greenhouse gases simultaneously will affect the earth, the will be the depletion of the ozone layer and this will lead to the global warming and climate change whereas they will be extreme weather changes and the whole earth is either the temperatures will drop or increase, or experience high or low rainfalls, they will be experiences of floods and drought.
The solution to the energy crisis it has to be cleanly produce and safe not the present dirty energy that we use or that we generate of which it minimizes resources as they are more used in the production of energy than in the economy and if it continue to be used in no time the resource will be scarce. Now the solution has to be to produce clean energy that will not threaten the species nor its inhabitants, and the energy has to be produced without any contribution of natural resources. Therefore nuclear can be the solution to our crisis and it can end the paradigm that one must produce energy and dirt simultaneously. Energy it can be produce without produce any dirt and it can be produce without using any fossil fuel from nature which is going to be scarce in years to come. But because the nuclear energy mainly make uses of the elements then they won’t be any uses of fossil fuels but they will be using fusion or fission reactions to produce energy.
Unfortunately, many people who do not understand the workings of nuclear physics are unnecessary fearful of nuclear power plant, and public protest are common. Nuclear power remains one of the cheapest and cleanest modes of power generation, and makes use of fuels that are available in almost unlimited supply. Nuclear reactors used in nuclear energy can be used for various purposes, but most well-known of these is probably the production of electricity in a nuclear, power plant.
PRODUCTION OF ELECTRICITY
Changes can occur in a structure of nuclei of atoms. These changes are called nuclear reactions. Energy created in a nuclear reaction is called nuclear energy, or atomic energy. Nuclear energy is produced naturally and in man-made operations under human.
- NATURALLY: some nuclear energy is produced naturally. For example, the sun and other stars make heat and light by nuclear reactions.
- MAN-MADE: nuclear energy can be man-made too. Machine called nuclear reactors, parts of nuclear power plants, provide electricity for many cities. Man-made nuclear reactions also occur in the explosion of atomic and hydrogen bombs.
Nuclear reaction take place in the reactors called nuclear reactors.
Nuclear reactors are devices that control fission reactions producing new substances from the fission product and energy. Nuclear power stations use uranium in fission reactions as a fuel to produce energy. Steam is generated by the heat released during the fission process. It is this steam that turns a turbine to produce electric energy. There is a nuclear reactor called pressurized-water reactor. The nuclear power plant at Koeberg, near Cape Town in the Western Cape, is an example of such reactor. The energy released by nuclear reaction heats water in the reactor vessel, causing convection current that circulates the water through the vessel. Because the water is under extreme pressure, it does not boil. This superheated water is passed through a heat exchanger, and passes its heat on to a secondary water system, which is allowed to boil and precede steam. The steam is produce over a turbine, which is connected to a generator. The spinning turbine thus generates electricity. The steam is then cooled, and it condenses and flows back into the heat exchanger. The advantage of this system is that the two water systems are completely separated, so the radioactive material in the reactor is prevented from contaminating anything in the surrounding areas. Although it seems simple, the greatest difficulty with this reaction is to control the chain reaction that is set up. This is done by means of control rods, which can be moved in and out of the core (where the radioactive fuel is). These control rods serve to absorb neutrons produced by the fission reaction. In this way, the number of neutrons released can be maintained, so that the reactor does not become hypercritical. Such a hypercritical reaction can lead to nuclear meltdown, a situation where heat cannot be removed from the reactor fast enough by the coolant, so that the reactor fuel overheats and melts. This might lead to explosion and the radioactive material in the atmosphere as happened in 1986 in the world peacetime nuclear disaster in the world, at Chernobyl in Ukraine. South Africa is planning the building of pebble-bed nuclear reactors. This type of this reactor is an improvement on the design of the pressurized-water reactors, and is regarded as the exceptional safe. In a pebble-bed reactor, increased temperatures actually slow down the nuclear reaction. This built-in safety mechanism prevents the reactor from going into the hypercritical state, even if there is a complete system failure at the power plant.
In nuclear fission, the nuclei of atoms are split, causing the energy to be released. The atomic bomb and nuclear reactors work by fission. The element uranium is the fuel used to undergo the nuclear fission to produce energy to produce energy since it has many favorable 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.
Nuclear fission involves delicate balance within the nucleus between nuclear attraction and electrical repulsion between protons. In all known nuclei the nuclear forces dominate. In uranium, however, this domination is tenuous. If the uranium nucleus is stretched into an elongated shape, the electrical forces may push into an even more elongated shape. If the elongation passes a critical point, nuclear forces yields to electrical ones, and the nucleus separates. This is fission. The absorption of a neutron by a uranium nucleus supplies enough energy to cause such an elongation the resultant fission process, may produce many different smaller nuclei.
The combined mass of the fission fragments and neutrons produced is in fission less is less than the mass of the original uranium atom. The tiny amount of missing mass converted to this good amount of energy is in accord with Einstein’s relation E is equal to mc squared. The energy of fission is mainly in the form of kinetic energy of the fission fragments that fly apart from one another, with some kinetic energy given to ejected neutrons and the rest to the gamma radiation. This reaction energy releases 200,000,000electron volts (by comparison, the explosion of the TNT molecule releases 30 electron volts.
The scientific world was jolted by the news of nuclear fission not only because of enormous energy release but also because of the extra neutrons liberated in the process. Typical fission reaction releases an average of about two or three neutrons. These new neutrons can in turn cause the fissioning of two or three other atomic nuclei, releasing more energy and a total of from four to nine more neutrons. If each of this splits just one nuclei, the next step in reaction will produce between eight and twenty seven neutrons and so on. Thus, a whole chain reaction can proceed at an ever accelerating rate.
If a chain reaction occurred in a chunk of pure U-235 the size of a baseball; an enormous explosion would likely result. The uranium separation in these days is more accomplish with a gas centrifuge. Uranium hexafluoride is whirled in a drum of tremendously high rim speeds. Under the centrifuge force, the heavier U-238 gravitates to the outside like milk in a diary separator, and gas rich in lighter U-235 is extracted from the centre. Engineering difficulties, only recently overcome, prevented the use of this in Manhattan project.
Within less than a year after the discovery of fission, scientist realized that a chain reaction with ordinary uranium metal might be possible if the uranium was broken up into smaller lumps and separated by a material that slow down neutrons. Enrico Fermi, who to America from Italy at the beginning of 1939,led the construction of the first reactor or atomic pile, as it was called-in a squash court underneath the grandstands of the university of Chicago’s Stagg field. His group achieved the first self-sustaining controlled release of nuclear energy on December 2, 1942.
THE THREE STEPS OF NUCLEAR FISSION
- It may cause fission of a U-235 atom
- Escape from the metals into non-fissionable surroundings, or
- Be absorbed by U-238 without causing fission.
To make the first fate more probable, the uranium was divided into discrete parcels and buried at regular intervals in nearly 400 tonnes of graphite, a familiar form of carbon. A simple analogy clarifies the function of the graphite
In nuclear fusion, the nuclei of atoms are joined together, or fused. This happens only under very hot conditions. The sun, like all other stars, creates heat and light through nuclear fusion. In the sun, hydrogen nuclei fuse to make helium. The hydrogen bomb, humanity’s most powerful and destructive weapon, also works by fusion. The heat required to start the fusion reaction is so that an atomic bomb is to provide it. Hydrogen nuclei fuse to form helium, and in the process it releases huge amounts of energy. Although, it provides a huge explosion.
Atomic nuclei are positively charge, fusion to occur; they normally must collide at very high speed in other to overcome electrical repulsion. The required speeds correspond to the extremely high temperatures found in the centre of the sum and stars. Fusion brought about by high temperatures is called thermonuclear fusion that is the welding together of atomic nuclei by high temperature. In the hot central part of the sun, approximately 657 million tonnes of hydrogen are converted into 653 million tons of helium each second. The missing four million tons of mass is discharged as radiant energy. Such reactions are, quite literally, nuclear burning. Most of the energy of nuclear fusion is in the kinetic of fragments, mainly neutrons. When the neutrons of are stopped and captured, the energy of fusion is turned into heat. In fusion reaction of the future, part of this heat is transformed into electricity.
Thermonuclear fusion is analogous to ordinary chemical combustion. In both chemical and nuclear burning, a high temperature starts the reaction; the release of energy into by reaction maintains a high enough temperature to spread the fire. The net result to the chemical reaction is a combination of atoms into more tightly bound molecules. In nuclear reactions, the net result is more tightly bound nuclei. The difference between chemical and nuclear burning is essential one of a scale.
Mile stones in history of nuclear energy
- December 2, 1942: The nuclear age began at the University of Chicago when Enrico Fermi made a chain reaction in a pile of uranium.
- August 6, 1945: The United States dropped an atomic bomb on Hiroshima, Japan, killing over 100 000 people.
- August 9, 1945: The United States dropped an atomic bomb on Nagasaki Japan, killing over 40 000
- November 1, 1952: the first vision of the hydrogen bomb (thousands times more powerful than the atomic bomb) was exploded by the United States for testing purpose
- February 21, 1956: the first major power plant was opened in England.
People are afraid of the consequences of nuclear as is harmful if not controlled with caution. Since the exploding of the power plant station in Chernobyl, Russia. People are scared if the same case could happen if nuclear power plant stations are created. Although the nuclear has the consequences is still has the advantages.
ADVANTAGES AND DISADVANTAGES OF NUCLEAR ENERGY
ADVANTAGES OF NUCLEAR ENERGY
- The earth has limited supplies of coal and oil. Nuclear power plants could still produce electricity after coal and oil become scarce.
- A nuclear power plant needs less fuel than ones which burns fossil fuels. One tons of uranium produces more energy than is produced by million tonnes of coals or million barrels of oil.
- Coal and oil burning plants pollutes the air. Well-operated power plants do not contaminants into the environment.
DISADVANTAGES OF NUCLEAR ENERGY
The nations of the world now have more than enough nuclear bombs to kill every person on Earth. The most powerful nations-Russia and United States have about 50 000 nuclear weapons between them. What if there were to be a nuclear war? What if terrorist got their hands on nuclear weapons? Or what if nuclear weapons were launched by accident?
- Nuclear explosion produce radiation. The nuclear radiation harms the cells of the body which can make people sick or even kill them. Illness can strike people years after their exposure to nuclear radiation.
- One possible type of reactor disaster is known as meltdown. In such an accident, the fission reaction goes out of control, leading to a nuclear explosion and the emission of great amounts of radiation.
- In 1979, the cooling system failed at the Three Mile Island nuclear reactor near Harrisburg, Pennsylvania. Radiation leaked, forcing tens of thousands of people to flee. The problem was solved minutes before a total meltdown would have occurred. Fortunately, there no deaths.
- In 1986, a much worse disaster struck Russia’s Chernobyl nuclear power plant. In this incident, a large amount of radiation escaped from the reactor. Hundreds of thousands of people were expose to the radiation. Several dozen died within few days. In the years to come, thousands more may die of cancers induced by the radiation.
- Nuclear reactors also have waste disposal problems. Reactors produce nuclear waste products which emits dangerous radiation. Because they could kill people who touch them, they cannot be thrown away like ordinary garbage. Currently, many nuclear wastes are stored in special cooling pools at the nuclear reactors.
- The United States has being planning to move the nuclear wastes to a remote underground dump.
- In 1957, at a dump site in Russia’s Ural mountains, several hundred miles from Moscow, buried nuclear wastes mysteriously exploded, killing dozens of people
- Nuclear reactors only last for forty to fifty years
THE FUTURE OF NUCLEAR ENERGY
Some people think that nuclear energy is here to stay and we must learn to leave with it. Others say that we get rid of all nuclear weapons and power both sides has their cases as they are advantages and disadvantages to nuclear. Still others have opinions that fall somewhere in between.
Nuclear energy is the solutions that ends the paradigm of consuming non-renewable fossil fuels and decreases the threats of climate change . Although it has its consequences that are more than just a climate change but this time is about our health and if there will be a safe world if this method is followed. Let’s look a way back where Chernobyl nuclear power plant has struck into the meltdown that left thousands of people sick and hundreds dead because of the radiation that destroys the living cells and can result in cancer, burns. It may be and if it is it must be designed inherently safe and operated responsible, to avoid meltdowns and unconditional hypercritics.