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paper TOPIC（由留学生论文指导中心提供）
How A Nuclear Power Plant Works?
WRITER:
Jim Philbert Rowe, Class 09-5,English Department,Foreign Language School, Hainan Normal University
DATE:
April, 10. 2011
SPECIFIC PURPOSE
To inform my audience about how a nuclear plant generate power.
BRIEF INTRODUCTION:
The devastating earthquake and tsunami in Japan caused a nuclear meltdown at Fukushima Daiichi Nuclear Power Plant.And the accidents are drawing people's concern about how the nuclear plant works, as well as why the accidents happened.
指导paper How A Nuclear Power Plant Works?
The devastating earthquake happened in Japan last month with a magnitude of 9.0 caused a tsunami which has killed tens of thousands of people's life. Another serious problem followed by the earthquake is the nuclear accident in Fukushima. However, workers are still trying to contain radiation leaks at Fukushima Daiichi nuclear power plants in Japan, since reactors were damaged by the massive earthquake and tsunami.After the disaster, nuclear safety has become a great public concern. The Accidents are drawing people's concern about how a nuclear power plant works, as well as why the accidents happened.
Now, when it comes to the use of nuclear energy, you may ask, "Why do we use nuclear power? "
Unlike burning fossil fuels, using nuclear fission to generate electricity produces no soot or greenhouse gases. This helps keep the skies clean and doesn't contribute to global warming. The World Nuclear Association estimates that the electricity industry would add 2.6 billion tons of carbon dioxide to the atmosphere each year if it used coal power instead of nuclear.
Some governments also like nuclear power because it reduces their dependency on foreign oil.
Finally, the fuel used to power nuclear reactors is very compact in comparison to fossil fuels. For instance, one pound of uranium can supply the same energy as 3 million pounds of coal. This makes it attractive for use in nuclear-powered vehicles like submarines, aircraft carriers and spacecraft.
Now, knowing the advantages of nuclear energy, do you know How much of the world's electricity comes from nuclear power?
Sixteen percent of the world's electricity is supplied by nuclear power, according to the World Nuclear Association. The electricity is produced by 440 nuclear reactors in 31 countries.
The United States has the most reactors with a total of 104, which are responsible for producing nearly 20 percent of the country's electricity.
The country that gets the highest percentage of its electricity from nuclear power is France. Its 59 reactors generate more than 78 percent of its electricity.
In China, it is estimated that there are 4 nuclear power plants with 11 reactors which are now running, not including 4 nuclear power plants in Taiwan. In addition, the government of Mainland China announced that there will be 30 extra nuclear power plants built by the year of 2020.
Nevertheless, since nuclear energy is so popular, How does a nuclear power plant produce electricity?
A nuclear power plant is basically a steam power plant that is fueled by a radioactive element, like uranium.
The fuel is placed in a reactor and the individual atoms are allowed to split apart. The splitting process, known as fission, releases great amounts of energy.
This energy is used to heat water until it turns to steam.
From here, the mechanics of a steam power plant take over. The steam pushes on turbines, which force coils of wire to interact with a magnetic field. This generates an electric current.
The reactors experiencing problems at Japan's Fukushima Daiichi nuclear plant are boiling water reactors -- the second most common kind of nuclear power reactor.
In a boiling water reactor, water heated by nuclear fission boils and turns into steam which powers a generator. The steam is then turned back into water by a condenser and used again.
The most common type of nuclear power reactor is a pressurised water reactor.
In a pressurised water reactor, hot pressurised water from the reactor's core boils water in a separate circuit, making steam that turns a turbine. Water from the reactor and water that is turned into steam are in separate pipes and never mix.
In Fukushima nuclear accident, the reactors of the plants were supposed to shut down, and the emergency generators were supposed to pump water into the reactors to cool them down. Remember, fission generates heat, you wanna stop heat quickly, you need to cool it down.But, in one of those 3 reactors, the back-up generators failed. Experts are blaming that on flooding from the tsunami. Another element - Hydrogen, started building up inside the facility until it caused an explosion that blew the roof off. The reactor was not damaged in the explosion, that's a big concern here, a problem with the reactor. As we known, the uranium inside of it is radioactive, and if too much of that radiation gets out, it could contaminate air and water, and lead very serious health problems.
And that's how it works.Only by knowing how the nuclear power plant works, can we prevent those accidents from happening again. paper （由留学生论文指导中心提供）
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