Nuclear_Energy

NUCLEAR ENERGY - By Colton Every atom has a nucleus, which is where the word “nuclear” comes from. There are over 440 nuclear power reactors in 47 countries. 16 percent of the world’s electrical energy is nuclear energy. Geothermal energy, when heat comes to the surface from the earth’s core, is from radioactive decay of uranium, and is another form of nuclear energy. Canadian mines produce more than a quarter of the world’s uranium. HOW IT WORKS Energy that is made in a nuclear reaction is called nuclear or atomic energy. Nuclear reactors can provide energy for entire cities. Nuclear power plants work in the same way that a coal burning power plant does. Both heat water into pressurized steam, which drives a turbine generator. The difference is the way the water is heated. Nuclear power plants use heat from nuclear fission. Nuclear power plants need a lot of water, to make steam and to cool the system, so they are usually built near water. There are two ways to produce nuclear energy, by splitting nuclei (fission) or joining nuclei (fusion). Nuclear fission is when one atom splits into two and releases energy. Nuclear reactors and atomic bombs use nuclear fission when uranium atoms split. Uranium is used because the atoms can be split easily. Nuclear fission with uranium happens in nature. Albert Einstein discovered a little bit of mass could produce a huge amount of energy through nuclear fission. A free neutron is fired into a uranium atom, causing it to split into two lighter atoms and throwing off two or three new neutrons. These new neutrons cause a chain reaction and split more uranium atoms. This splitting of an atom releases a huge amount of heat energy and gamma radiation. Nuclear fusion is when atoms are joined. The H-bomb or hydrogen bomb uses fusion. Nuclear fusion requires a huge amount of heat, an atom bomb is actually needed to make enough heat to cause nuclear fusion, making a hydrogen bomb explode. A hydrogen bomb is thousands of times more powerful than an atomic bomb. The sun and stars create their heat and light energy from nuclear fusion. ADVANTAGES Nuclear power is clean and it is not a fossil fuel. It isn’t affected by fluctuating oil and gas prices. It can provide energy when we have used up all the coal and oil. The world’s energy needs are growing, but the coal and oil are being used up. Carbon dioxide emissions are small with nuclear energy compared to coal and natural gas. Nuclear energy releases less radioactivity into the atmosphere than a coal fired power plant. It produces a million times more energy per unit weight than fossil fuel. Nuclear medicine uses radioactivity to detect certain diseases with x-rays and cat scans. It also uses radioactivity to treat certain diseases such as cancer. Nuclear engines need no air and very little fuel. There are nuclear powered submarines. DISADVANTAGES Mining and purifying uranium hasn’t been a clean process. Transporting nuclear fuel risks contamination. Nuclear energy is a non-renewable resource. Once the uranium is all mined and used up, there won’t be any more. Nuclear power plants are large and very expensive. Nuclear reactors only last 40-50 years. Nuclear power can only be used to generate electricity. You cannot split atoms in a fireplace or use them to drive a car. This is because nuclear power needs special engineering to control its safe release and thick shielding to prevent the escape of dangerous radioactivity. Once the fuel is used up, it is still radioactive. Radiation can kill or injure anybody exposed to it. It can cause cancers to develop years later, or even damage the body so that children born later are affected by it. The world’s nuclear plants produce 2,000 metric tons of radioactive waste per year. Waste emits radiation and heat, and will eventually corrode any container that holds it. It takes tens of thousands of years for the waste to become safe. In a nuclear power plant, there is the danger of meltdown, when the fission reaction becomes out of control, which causes an explosion and large amounts of radiation to be exposed. Nuclear weapons are another disadvantage to nuclear power, as they are a threat to world peace. Nuclear reactions cause atomic or hydrogen bombs to explode. There are enough nuclear bombs on earth to kill everyone on earth. HISTORY 1942 – Nuclear age began when Enrico Fermi made a chain reaction in uranium. 1945 – USA dropped an atomic bomb on Hiroshima, killing 100,000 people and then at Nagasaki, killing 40,000 more. 1952 – USA tested first large hydrogen bomb 1956 - The first major nuclear power plant opened in England 1979 - Three Mile Island nuclear reactor’s cooling system failed, radiation leaked, problem was solved just minutes before a meltdown. 1986 – Chernobyl disaster – Ukraine – nuclear reactor exploded, throwing 50 tons of radioactive material into the surrounding area, including millions of acres of forest. Hundreds of thousands of people were exposed, 30,000 people had to be evacuated, several dozen died within a few days, thousands died from resulting cancer years later. 2011 – Japanese earthquake and tsunami – plant was more modern and was able to shut down fission reactions within 10 minutes, but there was a problem with the cooling, resulting in radioactivity leaks. BIBLIOGRAPHY Brain, Marshall and Robert Lamb. “How Nuclear Power Works.” How Stuff Works. http://science.howstuffworks.com/nuclear-power2.htm/ Hawkes, Nigel. Nuclear. New York, NY: Aladdin Books Ltd., 1981. Johann, John and Greg. “Nuclear Energy”. ThinkQuest. http://library.thinkquest.org/3471/nuclear_energy.html Morris, Neil. Nuclear Power. North Mankato, MN: Smart Apple Media, 2007. Robertson, J.A.L. “Nuclear Energy”. The Canadian Encyclopedia. 2012. http://thecanadianencyclopedia.com/articles/nuclear-energy