Реферат: Ядерная Радиация \english\

Nuclear Radiation

Nuclear energy was discovered in the process of creating the atomic bomb. After scientists conducted more experiments, they found that nuclear power was a clean and efficient way to produce energy. “The first nuclear reactor was created on December 2, 1942, at the University of Chicago by Enrico Fermi.” (Editors of Scientific America, 1995). The discovery of nuclear energy provided a new source of energy and an alternative to the use of natural resources: such as coal, oil, water, and wood. At the same time, nuclear energy could be used in a destructive way, such as the atomic bomb.

At that time, the discovery of a new source of energy was a very significant event. By using a small amount of plutonium and uranium, two radioactive elements, an enormous amount of energy could be obtained. Nuclear energy can be produced in two different ways, by the fission or fusion process. Fission involves the breaking up of heavier atoms into lighter atoms. In a nuclear fission reaction, two smaller nuclei of approximately equal mass are formed from the splitting of a large nucleus. This splitting of an atom produces a large amount of energy. This process is the most common form of nuclear power. Fusion is a method that combines lighter atoms into heavier atoms. In a nuclear fusion reaction, a large nucleus is formed from two small nuclei joined together. Fusion reactions are difficult to produce because of the repulsion of the atom’s negatively charged electron clouds and the positively charged nucleus. (LeMay, Beall, Robblee, Brower, 1996). Fusion is mostly used to create the hydrogen bomb. (The World Book Encyclopedia, 1990). The byproduct of nuclear energy is radiation. Radiation is created from the particles (strontium-90, cesium-137, radon-222, krypton-85, and nitrogen-16) that are given off as a result of the splitting of atoms. (Gale Encyclopedia of Science, 1996) (Demmin, 1994).

As time went on, the attitudes of people towards nuclear energy changed. There were many positive and negative aspects for the use of nuclear power. Recently, people worldwide have started questioning the continued use of nuclear power. Due to the deaths resulting from the 1986 Chernobyl nuclear reactor accident, as well as the adverse effect the aftermath of the accident had on the environment, there has been a public outcry concerning the safety of society. As with many controversial issues, this topic has been widely debated, but a solution has not been determined.

The positive aspects of the use of nuclear energy are that the supply of natural resources does not have to be depleted, and also it is clean. It takes a great amount of natural resources to create a small amount of energy. On the other hand, a very small amount of plutonium and uranium is necessary for the creation of a large amount of nuclear energy. This is important since there are relatively small amounts of plutonium and uranium in the earth’s crust. Compared to the production of power using coal, the creation of power generated by nuclear energy does not pollute the air. As coal burns, there are poisonous fumes that could cause sickness, if the area is not properly ventilated. As the cost of electricity rose, the government was forced to look for an alternative source of energy, which they discovered in nuclear reactors.

One of the major disadvantages of a reactor is the disposal of the nuclear waste which harms the environment. “There are 434 nuclear reactors in the world and 110 of them are in the United States.” (Wasserman, 1996) Not a single one is functioning without polluting the environment. Attempts to store nuclear wastes have not been very successful. One such attempt is to bury the nuclear waste underground, but the leakage of nuclear waste has poisoned the groundwater. Another attempt is to put the nuclear waste into deep ocean water. Later, this was rejected by the public and also, in violation of an international treaty because of the possibility of harming the ocean. Another problem to the environment is the leakage of radioactive waste from space. This problem is not pollution to the earth’s environment, but pollution of space. There is no way to dispose of the nuclear waste in space.

The most significant drawback on this controversial issue is the threat of a disaster. The two most serious situations were the accident at Chernobyl and the explosion of the hydrogen bomb on Hiroshima. The first time that people discovered the dangers of nuclear power was when the atomic bomb was dropped, August 6, 1945, on Hiroshima. The effects of the bomb was that it destroyed 4.7 square miles of the city. Approximately 70,000 people were killed and about another 70,0000 people were injured. Many people died later as a result of nuclear radiation and radiation sickness. (The World Book Encyclopedia, 1990). The most serious nuclear disaster was the Chernobyl accident that occurred April 26, 1986 in the Soviet Union. (Medvedev, pp.83-89.). An accurate number of deaths as a result of this accident is very hard to determine due to the secrecy of the U.S.S.R. surrounding this accident. (Marples, 1996). A study done by a team of scientists from both the United States and Japan has shown that there has not been any evidence found of genetic mutation, which are changes in heredity, in the children of the survivors of the bombing of Hiroshima. (Science News, 1996).

Following the Chernobyl accident, Soviet scientists suggest that there is evidence that radiation has exhibited genetic mutation in the parents who were exposed to radiation. According to them, the mutation was found in sperm and egg cells, which contain the genetic building blocks of future generations. The child’s DNA is a combination from both parents’ genetic makeup. When there is any sequence that the child has, but that sequence was not found in either parent, then this is called germline mutation. Ten years after the accident that occurred at Chernobyl, evidence of mutation, in the exposed areas of the country, indicates that radiation changed genetic makeup and that this has passed onto future generations. (Science News, 1996). Also, there has been an explosive increase in childhood thyroid cancer in Belarus, Ukraine and the Russian Federation since 1986. This cancer is present in brothers and sisters of the same family, which indicates that the cancer is a result of the accident at Chernobyl. (Balter, 1995).

Whether the atom is used for peace or for war, man must contend with the hazards of nuclear radiation. This radiation may cause burns, diseases, and death. It may harm future generations by causing mutations.

In peacetime, the escape of radioactive particles from nuclear plants is the main radiation hazard. More nuclear power plants will be built if a significant amount of the world’s power is to come from uranium. As a result of these plants, huge amounts of radioactive material will be produced. The power plants must take necessary precautions to insure the communities are safe from the radiation that may escape.

In wartime, the most serious danger from radiation is near or below the place where the atomic bomb has exploded. If people are not killed by the bomb, then they have to deal with the radioactive fallout. Even at a distance from the blast, the injury can be serious.

The use of radiation has many positive attributes, but at the same time, the significance of the drawbacks are overwhelming. No government nor scientist can guarantee the safety of nuclear plants. Without this guarantee, there is an immediate concern for the welfare of the world. I believe countries around the world should begin a gradual process of shutting down nuclear plants and begin making a much greater effort to develop widespread use of other sources of energy, such as wind and solar power.

In the last decade, public concern for the use of nuclear energy has increased dramatically. Few can debate that nuclear energy is clean, and can be produced without using hardly any natural resources. Likewise, few can debate that radiation is harmful to the environment, unsafe, and a great danger for all living things. Scientists and mankind have to weigh the positive as well as the negative aspects of nuclear radiation, and then decide what source of energy the future holds that will benefit not only all living things, but also the environment.

REFERENCES

Balter, Michael. ( 1995). “Chernobyl’s Thyroid Cancer Toll.” Science . vol. 270, no. 5243, pp. 1758-1759.

Demmin, Peter E. (1994). Reviewing Chemistry . Amsco School Publications, Inc. New York. P. 85.

LeMay, Eugene H. Jr., Beall, Herbert, Robblee, Karen M., and Brower, Douglas C. (1996). Chemistry Connections to Our Changing World . Prentice Hall. New Jersey. Pp. 792-798.

Marples, David R. (1996). “The Decade of Despair.” The Bulletin of the Atomic Scientist . vol.52, no.3, pp.22-31.

Medvedev, Grigori. (1991). The Truth About Chernobyl . Basic Books. A Division of Harper Collins Publishers. pp. 83-89.

Science News . (1996). “Radiation Damages Chernobyl Children.” editors of Science News . vol. 149, no. 17, p. 260.

Scientific American . (1995). “Disposing of Nuclear Waste.” Editors of Scientific American . p. 177.

The Gale Encyclopedia of Science . (1996). Bridget Travers, editor. New York. vol. 5, pp. 3008-3009.

The World Book Encyclopedia . (1990). Field Enterprises Educational Corporation. Chicago. vol. 9 p. 230. and vol. 1 p. 832.