Реферат по предмету "Иностранный язык"


Nuclear History Essay Research Paper WHAT IS

Nuclear History Essay, Research Paper

WHAT IS NUCLEAR ENERGY ?

Nuclear energy is made up of tiny atoms. All matter has atoms. One drop of water has one six tillion atoms. It would take one hundred million atoms to equal the length of one centimeter. An atom is mostly empty space. At the center of an atom, there is a nucleus. The plural of nucleus is nuclei. Around the nucleus is a cloud of moving electrons. All the atom’s mass is in the nucleus.

The nucleus is made up of protons and neutrons. A proton and a neutron have the same amount of mass. An electron has much less mass than a neutron or proton. It would take 2,000 electrons to equal the mass of one proton! The weight of an atom is based on the sum of the number of protons and neutrons.

HOW DOES NUCLEAR POWER WORK ?

Nuclear energy can be used to make electricity. But before you can have the electricity, you need to release the energy from the atom. It can be released from atoms in one of two ways: nuclear fusion or nuclear fission.

In nuclear fusion, energy is released when atoms are combined or fused together. This is also how the sun produces energy.

In nuclear fission, energy is released when atoms are split apart. Nuclear power plants use nuclear fission to produce electricity.

The fuel most used for nuclear fission is uranium.Uranium is called a nonrenewable source, though it is a common metal found in rocks all over the world. Nuclear plants use uranium as a fuel because it’s atoms are easily split.

During nuclear fission, the uranium atom splits, releasing a great amount of energy in the form of things smaller than atoms called neutrons. The neutrons continue to bombard other uranium atoms, and the process repeats it self. This is called a nuclear chain reaction.

Now you know how we get the energy out of the atom. Now you’re going to know how a nuclear power plant works.

Most electric power plants use fossil fuels like coal or natural gas to make electricity. Not nuclear power plants. Instead, nuclear power plants use the heat energy given off during nuclear fission to produce electricity.

The fission reaction takes place inside the reactor of a nuclear power plant, at the center of a nuclear reactor core. The core of the reactor contains the uranium fuel.

The uranium fuel is formed into ceramic pellets. The pellets are about the size of your fingertip, but can produce the same amount of energy as 120 gallons of oil! These energy-rich pellets are stacked in 12-foot fuel rods. A bundle of fuel rods is called a fuel assembly.

Nuclear fuel generates heat in a reactor just as coal or oil generator heat in a boiler. The heat is used to boil water into steam. The steam is then blasted against huge turbine blades. As they turn, they drive generators that make electricity. Afterword, the steam is changed back into water and cooled in a separate structure at the nuclear power plant called a cooling tower. In this way, the water can be used again and again.

HOW MUCH DOES IT COST ?

Nuclear energy costs a lot, compared to fossil fuel plants. Even though nuclear energy costs less, it takes more to set up a nuclear enrgy plant. So nuclear energy may cost less at a time, but at the beginning it costs more than fossil fuels.

HOW DOES IT AFFECT THE EARTH ?

One of the best kept secrets about nuclear power is its impact on the environment. There is very little. Making electricity causes no air pollution because fuel is not burned as it is in coal and oil-fired plants. Using nuclear energy may be one way to solve pollution problems linked to acid rain and the greenhouse effect.

People are using more and more electricity. Some experts predict we will have to use nuclear energy to produce the amount of electricity people need at a cost they can afford. Whether or not we should use nuclear energy is a decision our society will have to make.

Nuclear Waste

After three or so years, the fuel rods are used up and must be replaced. Fuel that has been removed from the nuclear reactor is called spent fuel. Nuclear power plants do not produce as much waste as power plants that burn fossil fuels.The problem is that nuclear wastes are highly radioactive.

The spent fuel is usually stored near the reactor in a deep pool of water called the spent fuel pool. Here, the spent fuel pool cools down and the radioactivity through a natural process called radioactive decay. In three months, the spent fuel will have lost 50% of its radiation, in one year it will have 80% and in ten years it will have lost 90%. Nevertheless, because some radioactive remains for as long 1,000 years, the waste must be carefully and permanently isolated from the environment.

WHAT IS THE AVAILABILITY ?

Nuclear energy is in some ways a plentiful source, and a less available source. Nuclear energy comes from atoms and uranium. (Uranium can be found in many rocks around the world.)Once the uranium is burned, the nucleus of the atom then starts a nuclear chain reaction, which soon makes electricity. So in that way, nuclear energy is a very plentiful source….At the time. If we were to stop using coal, oil, natural gas, hydroelectricity, and solar energy, we wouldn’t have nuclear energy for very long. You see, nuclear energy may be a plentiful source now, but if we stopped all other types of energy, we would simply run out in a matter of days. Not to mention the amount of nuclear waste that would come upon us.

IS IT RENEWABLE ?

Nuclear energy cannot be renewed like hydroelectric or some chemical energies. After the atoms from the uranium are all burnt, there is nothing to be reburnt, except some radioactive waste. But if that were to be burned, not only would it simply not work, but the impact on the environment would be tremendous.

WHAT ARE THE DIFFERENT USES ?

Nuclear energy can be used for 3 different things.

1. Nuclear energy can be used to make weapons, such as the nuclear bomb. In World War Two, scientists discovered that they could use a nuclear chain reaction to make a bomb. This bomb was first tested on Japan during the war. The explosion blew up most of Japan. The name for this weapon was the Atomic Bomb.

2. Nuclear energy can be used to push battle ships and other Naval ships. Instead of using fossil fuels, ships use nuclear heat to push the propellers for movement.

3. Nuclear energy can also be used for electricity. But only 16% of the U.S. uses nuclear energy as an electricity source.




Не сдавайте скачаную работу преподавателю!
Данный реферат Вы можете использовать для подготовки курсовых проектов.

Поделись с друзьями, за репост + 100 мильонов к студенческой карме :

Пишем реферат самостоятельно:
! Как писать рефераты
Практические рекомендации по написанию студенческих рефератов.
! План реферата Краткий список разделов, отражающий структура и порядок работы над будующим рефератом.
! Введение реферата Вводная часть работы, в которой отражается цель и обозначается список задач.
! Заключение реферата В заключении подводятся итоги, описывается была ли достигнута поставленная цель, каковы результаты.
! Оформление рефератов Методические рекомендации по грамотному оформлению работы по ГОСТ.

Читайте также:
Виды рефератов Какими бывают рефераты по своему назначению и структуре.

Сейчас смотрят :