Реферат: Nuclear Energy Essay Research Paper History Of
Название: Nuclear Energy Essay Research Paper History Of Раздел: Топики по английскому языку Тип: реферат |
Nuclear Energy Essay, Research Paper History Of Power Modern civilisation depends largely on energy. Without it our lives would be reduced to the level of a caveman?s. We would have nothing to power the equipment we rely on to get on with our daily lives. Life would in a way come to a standstill without energy. Without wood, we would not even be able to light fires for warmth or fire for cooking food. Our days would be spent huddling together in caves for warmth with only raw meat and vegetables to eat. This is a stark picture but it shows how vital energy is for human beings. Human progress has been closely linked to the discovering of new means of producing power. At first, man could only burn wood for heat. Later mankind learned how to use coal. By the 1700?s, we discovered steam and which has brought to the industrial revolution that launched mankind towards our modern technological society. Since then many ways of producing power have been developed ? including oil, gas, nuclear and solar energy. From the time mankind discovered energy till today, energy consumption has increased more than a hundredfold. The illustration below shows clearly the increasing energy consumption since the stone ages. Why Nuclear Energy? Before we look into why nuclear energy is the best resource, we should look into the problems faced by current techniques of producing power. Problems With Current Energy Resources Depletion of Fossil Fuels Till today, 78% of the world?s energy is derived from the burning of fossil fuels. Fossil fuels include petroleum, natural gas, and coal. As a result, fossil fuels are being depleted at rates 100,000 times faster than they are being formed. The remaining recoverable fossil fuel in the world is thought to be about 10 trillion barrels of oil, enough to last mankind another 170 years at present consumption rates. This is likely to become less as the consumption rate will certainly increase. However this supply will eventually run out one day. Air Pollution With the heavy use of fossil fuels in today?s energy strategy, air pollution has become an increasing problem. A 1,000 MWe coal-fired power station produces about 7 million tonnes of carbon dioxide each year, plus perhaps 200,000 tonnes of sulphur dioxide which in many cases remains a major source of atmospheric pollution. Other waste products from the burning fossil fuels include large quantities of fly ash (typically 200,000 tonnes per year), containing toxic metals (substances that can cause cancer and genetic changes) as well as naturally-occurring radioactive substances. These pollutants have many effects on the respiratory system both long-term and short-term and can sometimes be fatal. Examples of diseases caused by air pollution are aggravated asthma, severe chest pain, gasping, aggravated coughing and chronic bronchitis. But children are the main concern of this problem. Because their respiratory system are still developing. They are more prone to these diseases than adults. Acid Rain What is acid rain? Acid rain as the name suggests is acidic. Water in the atmosphere combines with the gas Sulphur dioxide that is released together with carbon dioxide during the combustion of fossil fuels. The combinations of water and sulphur dioxide gas forms sulphuric acid and this is dangerous to both human beings and the environment. Greenhouse Effect Another problem raised is the greenhouse effect. Because of the excess carbon dioxide gases released day-by-day, a ?layer? of the gas forms in the atmosphere. As a result, the heat form the sun is kept in by that ?layer? of gas instead of being radiated out into space like it should be. This is the same principle as how a greenhouse keeps plants warm. The world temperature will be likely to increase due to the extra heat in the atmosphere and this will cause great devastation to the earth. Glaciers and ice fields would melt, causing low-lying countries to be flooded and the world?s climate would utterly change. Renewable Energy Alternative sources of producing have been found such as wind power, hydroelectric power (derived from running water through turbines as a fast rate), geothermal power and so on. These resources are categorised as renewable energy. But the problem with these sources of energy is that they do not produce enough energy to sustain the increasing need for energy in today?s times. Energy from renewable resources has to be produced in a very large scale in order to supply the world with enough energy. Although renewable energy sources is said to be environmentally friendly, at a large scale it is not. For example, for a hydroelectric dam to be big enough to supply energy for a country as big as Australia, the dam would have to be the size of Singapore times four. A vast area of land has to be cleared in order to build the dam and this might cause the extinction of rare plants and animals. Why Nuclear Energy? There are many reasons why nuclear energy is the best alternative source of energy. Nuclear energy will solve all of the problems faced by current sources of energy especially from the burning of fossil fuels. To find the advantages of nuclear energy, we have to compare it with another resource. For instance, let us compare a nuclear power plant and a power plant that burns coal. Nuclear Power Plant Coal Power Plant Resources needed to produce 1 million kilowatts of power 24 tonnes of uranium 3.1 million tonnes of coal From the table above we can see that 3.1 million tonnes of coal is needed to produce 1 million kilowatts of energy whereas only 24 tonnes of uranium is needed to produce the same amount. This proves that nuclear is more efficient and doesn?t use as much resources. Because of that, nuclear energy can be used for a longer period of time as there are still vast quantities of uranium available in the earths? crust. Coal-fired power stations worldwide consume over 2500 million tonnes of coal each year to produce 38% of the electricity. This compares with about 61,000 tonnes of natural uranium providing the fuel for the nuclear power stations which provide almost 17% of the world’s electricity. Much of the coal is used in the country in which it is mined, but often it has to be transported long distances, which requires considerable energy (and results in further greenhouse gas emissions). Nuclear fuel by comparison is extremely modest in volume and if necessary, can even be transported by aircraft. A 1000 MWe nuclear power station requires one truck-load delivery of enriched fuel per month, or an average of about 74 kg per day, which would fit in a small briefcase. An equivalent sized coal-fired station needs some 8600 tonnes of coal to be delivered every day. Besides being efficient energy wise, nuclear energy doesn?t emit any chemical or solid pollutants into the atmosphere during the production of nuclear energy. 7 million tonnes of waste, which consists of ash, sulphur dioxide and carbon dioxide gas is emitted from the burning of fossil fuels. This figure is more than double the amount of coal needed. These wastes contribute to the already worsening problem of air pollution. The amount of waste produced from the process of nuclear energy is only a small portion of the actual amount of uranium used and most of these wastes can be recycled to be used in reactors again. This amount of waste is a small amount considering the amount of poisonous gases emitted by the burning of fossil fuels. The waste is also easily manageable. Although it is highly radioactive, nuclear wastes are safe if it is contained properly whereas there is no way of containing the poisonous gases released by the burning of fossil fuels. Although the cost to build a nuclear power plant is very high, this is made up by cost of the production of power itself. A nuclear power plant is less expensive to operate than a fossil fuel plant mainly because that a nuclear plant uses a much smaller volume of fuel. |