Реферат: Nuclear Energy Essay Research Paper The Present

Nuclear Energy Essay, Research Paper

The Present Energy:

What’s the Deal??

When dealing with the world’s present sources of energy, the two most popular forms are nuclear and energy by fossil fuels. How long will these supplies last? Are they the most effective? Is it harmful to the environment? All of these questions must be addressed. Below is a description of how these sources produce energy.

What exactly is nuclear energy? We talk about it all the time, but what is it? Nuclear energy is energy that is obtained by splitting the nuclei of atoms. The atoms of most elements are stable; they never change. Some elements, however, have nuclei that under certain conditions can be split up. This process is known as nuclear fission. When fission takes place, very large amounts of energy are released. Nuclear fission can only take place in nuclear power plants. These plants are highly expensive. The fission process takes time, and must be carefully controlled. If the process were to accelerate in speed, a huge explosion could take place.

The process all begins in a reactor. This is where the atoms split. The reactor is equipped with control rods that are either pushed in or pulled out to keep fission under control. In these reactors, a heavy metal called uranium is collected. There are different types of nuclear reactors. The most common type, called a pressurized water reactor is shown below. This reactor uses water under pressure as a coolant. The water is pumped through the uranium core, where it absorbs the heat that is produced by fission. It then passes into a steam generator, where it heats the water into steam. Next, the steam travels to steam turbines that spin the electricity generators. The energy produced by a nuclear reaction is great, and can be harmful. Fission produces much energy that can be used for a long time. This is the process in which nuclei of atoms are turned into electricity. In other words, nuclear energy.

Another main source of energy today is coal. Coal is a fossil fuel, which means that it is the remains of plants and animals that lived in humid swamp-like forests. Lignite coal, or coal that has not been exposed to much heat or pressure contains a lot of moisture and is about 50 percent carbon. It is also a fairly soft substance with a brownish color. When this material was exposed to heat and pressure during the many years that it sat on earth, it hardened, and therefore contains nearly 90 percent carbon.

In order to turn coal into a high-energy fuel; the hydrogen content of the coal must be increased. The process of converting hard coal into a liquid fuel such as gasoline and fuel oil is called hydrogenation. In the most common method of hydrogenation, a mixture of crushed coal and oil is mixed with hydrogen gas at extremely high temperatures and pressure. The hydrogen gradually combines with the carbon molecules to form a liquid fuel.

Coal is burned at power plants and produces dark heavy smoke. Sulfur dioxide is a main ingredient in this smoke. Researchers are working to develop new, improved ways of producing energy by burning coal.

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