Nuclear Energy, the alternative fuel?
This project was made by: Nicholas S. Mathé and Andrew D. Matte of Selwyn House School
Nuclear energy is an important source of energy in today’s world. However, many people are concerned about the safety of nuclear power. Though nuclear energy has often been portrayed as harmful and dangerous to the environment and life in general, this is a gross misunderstanding. This report’s discussion will include the benefits of nuclear energy with regard to the environment, the processes involved in the production of nuclear energy, the functioning of nuclear reactors, and in particular Canada’s development of the CANDU reactor and the safety of nuclear energy production.
Nuclear energy is a beneficial source of energy for multiple reasons. Nuclear energy is, in truth, incredibly environmentally friendly. Nuclear plants also avoid the release of large quantities of harmful products to the environment when compared to other sources. Last year one nuclear power plant produced energy without the release of 56,000 tons of nitrogen oxides into the environment that would have been produced by burning fossil fuels to produce the same amount of energy. This is the equivalent of the emissions of 3 million cars running on fossil fuels (Don Williams,February 18, 2007). Nuclear plants also avoid the production and release of other chemicals into the environment which contribute to smog, pollution and ozone destruction (Don Williams,February 18, 2007). Medical problems for humans are also prevented since they avoid the use and release of many harmful products and chemicals (Don Williams,February 18, 2007). Nuclear energy has possibly the lowest impact on the environment, especially in relation to kilowatts produced, because nuclear plants do not emit harmful gases (Nuclear Energy Institute, 2007). Nuclear power plants are so environmentally friendly that the land around the plants provides healthy homes for endangered species of birds such as bald eagles, (Nuclear Energy Institute, 2007).
Nuclear power is a very efficient source. 25% of the global carbon dioxide released into the atmosphere is caused by energy generation using fossil fuels. Nuclear energy avoids this release (Louis A. Bloomfield, 2007). The energy produced by one CANDU fuel bundle would require 400 tonnes of coal, 270,000 litres of oil or 300 million litres of natural gas to produce. However this is avoided with a much smaller portion of uranium (Louis A. Bloomfield, 2007). In contrast to the large areas required by solar or wind generating systems, a nuclear generating station sits on 2-3 sq. km of land (Louis A. Bloomfield, 2007). The amount of free energy contained in nuclear fuel is millions of times the amount of free energy contained in a similar mass of chemical fuel such as gasoline, making nuclear fission a very efficient prosses. (Marshall Brain, 2007)
Nuclear Power is the use of nuclear reactions to produce energy (Marshall Brain, 2007). Nuclear energy is released when a material like uranium-235 undergoes nuclear fission and creates heat. Over 16% of the world's electricity is generated from uranium in nuclear reactors with Canada as the worlds second largest producer of uranium (Uranium Information Centre Ltd, unknown author, 2006). Uranium was apparently formed in super novae about 6.6 billion years ago. While it is not common in the solar system, today its slow radioactive decay provides the main source of heat inside the earth, causing convection and continental drift. (Uranium Information Centre Ltd, unknown author, 2006). It occurs in most rocks in concentrations of 2 to 4 parts per million and is as common in the Earth's crust as tin, tungsten and molybdenum. It is also found in seawater, and could ultimately be recovered from the oceans if necessary. (Uranium Information Centre Ltd Ltd, unknown author, 2006). Uranium-235 is the most useful form of uranium for nuclear power production. This is because U-235 can undergo induced fission. Inside a nuclear reactor when the U-235 nucleus of a uranium atom is hit by a free neutron, the nucleus will immediately absorb the neutron and then become unstable and split into two lighter nuclei, several fragments, two or three free neutrons, and lots of heat. The free neutrons then fly off and bump into new uranium nuclei and cause the process to repeat over and over, this continuing process is called a fission chain reaction (Marshall Brain, 2007).
Uranium ore can be mined by underground or open-cut methods, depending on the depth of its location. The uranium ore is converted into a stable form called yellow cake. These cakes are converted uranium hexafluoride (UF6), which enables it to be enriched. Enriching the uranium increases the content of U-235 isotope level form the natural 0.7% to a level of 3 to 4%. This is then turned into U-235 pellets which are used to make the fuel rods. (Uranium Information Centre Ltd, unknown author, 2006). Inside a nuclear reactor the uranium rods are grouped together in bundles and the heat resulting form the fission reaction is used to boil water contained in huge tanks and turn it into steam. This steam then turns a turbine which spins a generator to produce power.
More than 400 nuclear plants operate in 30 countries around the world, including more than 100 in the United States. (Nuclear Energy Institute, 2006). More than 17 percent of the world’s energy is supplied by nuclear plants (Nuclear Energy Institute, 2007). Nuclear energy is now becoming more desirable and 72 new plants are in construction around the world. It is an energy source that can be depended on. Nuclear energy is not subject to unreliable weather or climate conditions, unpredictable cost fluctuations, or dependence on foreign suppliers, so it’s good for both the producers of nuclear energy and good for the consumers (Nuclear Energy Institute, 2007).
Many people are still concerned about the safety of nuclear reactors. This is particularly true since the Chernobyl Nuclear Power Plant disaster in the Soviet Union in 1986 where many people died and others were exposed to dangerous radiation. It was the worst accident in the history of nuclear power. There was a large negative environmental impact and the soils in the area continue to contain high levels of radio activity. Another major concern is the storage and disposal of the nuclear waste. The spent fuel from nuclear power plants is highly radio active and toxic for hundreds of years. It needs to be handled carefully and there is no permanent storage for it yet developed. (Marshall Brain, 2007). However nuclear power does produce less waste material than fossil fuel based power plants (Marshall Brain, 2007). Besides the worry of radioactive contamination by accidents at nuclear power plants there is also worry about the potential for the attack or sabotage of the facilities as well as concerns for nuclear waste being used as a weapon.
Nuclear plants must meet strict safety guide lines and federal security requirements, as determined and monitored by various national nuclear regulatory commissions and regular inspections are done (Nuclear Energy Institute, 2007). Most plants include many safety features to protect against spills and safety is a primary concern for the reactor management teams. Safety is in fact such a great priority that the reactors have been designed to withstand the impact of hurricanes, tornadoes, floods, and airborne objects of a very substantial force (Nuclear Energy Institute, 2007). They also consist of several strong layers of steel to protect against any leakage of nuclear waste. Plant operators also have emergency procedures in place specifically for security situations, including automatic shutdown of the reactor in the event of an attack. (Nuclear Energy Institute, 2007).
Nuclear energy is an important energy source in the world today. When compared with other fuel sources, especially fossil fuels, it is found to have less harmful effects on the environment. It is also a tremendously efficient and cost effective source of energy. The CANDU reactor, a Canadian innovation, has had great success world wide. Nuclear energy has often been portrayed by its opponents as being a potentially dangerous energy source. No energy source is without its problems but overall nuclear plants have an impressive safety record. The future of nuclear energy will be dependent on how the countries of the world decide to consider its advantages and risks.
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