 |
|
Text 10. Nuclear Energy
The sun and stars are seemingly inexhaustible sources of energy. That energy is the result of nuclear reactions, in which matter is converted to energy. We have been able to harness that mechanism and regularly use it to generate power. Presently, nuclear energy provides for approximately 16% of the world's electricity. Unlike the stars, the nuclear reactors that we have today work on the principle of nuclear fission. Scientists are working like madmen to make fusion reactors which have the potential of providing more energy with fewer disadvantages than fission reactors. Changes can occur in the structure of the nuclei of atoms. These changes are called nuclear reactions. Energy created in a nuclear reaction is called nuclear energy, or atomic energy. Nuclear energy is produced naturally and in man-made operations under human control. Some nuclear energy is produced naturally. For example, the Sun and other stars make heat and light by nuclear reactions. Nuclear energy can be man-made too. Machines called nuclear reactors, parts of nuclear power plants, provide electricity for many cities. Man-made nuclear reactions also occur in the explosion of atomic and hydrogen bombs. Nuclear energy is produced in two different ways, in one, large nuclei are split to release energy. In the other method, small nuclei are combined to release energy. In nuclear fission, the nuclei of atoms are split, causing energy to be released. The atomic bomb and nuclear reactors work by fission. The element uranium is the main fuel used to undergo nuclear fission to produce energy since it has many favourable properties. Uranium nuclei can be easily split by shooting neutrons at them. Also, once a uranium nucleus is split, multiple neutrons are released which are used to split other uranium nuclei. This phenomenon is known as a chain reaction. In nuclear fusion, the nuclei of atoms are joined together, or fused. This happens only under very hot conditions. The Sun, like all other stars, creates heat and light through nuclear fusion. In the Sun, hydrogen nuclei fuse to make helium. The hydrogen bomb, humanity's most powerful and destructive weapon, also works by fusion. The heat required to start the fusion reaction is so great that an atomic bomb is used to provide it. Hydrogen nuclei fuse to form helium and in the process release huge amounts of energy thus producing a huge explosion.
Advantages and disadvantages of Nuclear Energy:
- The Earth has limited supplies of coal and oil. Nuclear power plants could still produce electricity after coal and oil become scarce.
- Nuclear power plants need less fuel than ones which burn fossil fuels. One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil.
- Coal and oil burning plants pollute the air. Well-operated nuclear power plants do not release contaminants into the environment.
The nations of the world now have more than enough nuclear bombs to kill every person on Earth. The two most powerful nations - Russia and the United States — have about 50,000 nuclear weapons between them. What if there were to be a nuclear war? What if terrorists got their hands on nuclear weapons? Or what if nuclear weapons were launched by accident?
- Nuclear explosions produce radiation. The nuclear radiation harms the cells of the body which can make people sick or even kill them. Illness can strike people years after their exposure to nuclear radiation.
- One possible type of reactor disaster is known as a meltdown. In such an accident, the fission reaction goes out of control, leading to a nuclear explosion and the emission of great amounts of radiation.
- In 1979, the cooling system failed at the Three Mile Island nuclear reactor near Harrisburg, Pennsylvania. Radiation leaked, forcing tens of thousands of people to flee. The problem was solved minutes before a total meltdown would have occurred. Fortunately, there were no deaths.
- In 1986, a much worse disaster struck Ukraine’s Chernobyl nuclear power plant. In this incident, a large amount of radiation escaped from the reactor. Hundreds of thousands of people were exposed to the radiation. Several dozen died within a few days. In the years to come, thousands more may die of cancers induced by the radiation.
- Nuclear reactors also have waste disposal problems. Reactors produce nuclear waste products which emit dangerous radiation. Because they could kill people who touch them, they cannot be thrown away like ordinary garbage. Currently, many nuclear wastes are stored in special cooling pools at the nuclear reactors.
- The United States plans to move its nuclear waste to a remote underground dump by the year 2010.
- In 1957, at a dump site in Russia's Ural Mountains, several hundred miles from Moscow, buried nuclear wastes mysteriously exploded, killing dozens of people.
- Nuclear reactors only last for about forty to fifty years.
Exercise 111 . Select the key words and expressions from the text for a five-minute conversation with your partners on the following topic: What are the Pros and Cons of Nuclear Energy?
Exercise 112. Translate the following words and word combinations into Ukrainian:
Nuclear power plant, to provide electricity, man-made nuclear reaction, to release energy, explosion of atomic and hydrogen bombs, favourable properties, the most powerful and destructive weapon, to harm the cells of the body, total meltdown, waste disposal problem, dangerous radiation, cooling pool, remote underground dump, inexhaustible source of energy, to escape from the reaction, to release contaminant.
Exercise 113. Translate the following sentences into English.
1. Перша атомна станція була побудована в Англії у 1956 році. 2. Вчені працюють над удосконаленням ядерних реакторів з метою підвищення ефективності й надійності їх експлуатації. 3. Ядерна енергія – це форма енергії, яка виникає в результаті ядерного поділу або злиття ядер. 4. Виробництво і використання будь-якого виду енергії супроводжується забрудненням навколишнього середовища. 5. У 1986 році в результаті аварії на Чорнобильській атомній станції сотні тисяч людей постраждали від радіоактивного випромінювання. 6. Одна тонна урану виробляє більше енергії, ніж декілька млн. тон вугілля чи нафти. 7. У деяких країнах атомна енергія є основним джерелом енергозабезпечення, наприклад, у Франції атомні станції виробляють 70% від загальної кількості енергії. 8. Ядерні реактори, побудовані на принципі злиття ядер, будуть безпечніші і більш ефективні.
Exercise 114. Answer the following questions.
1. What is nuclear energy? 2. How is nuclear energy produced? 3. What phenomenon is known as a chain reaction? 4. How does nuclear radiation affect people’s health? 5. What major problems are connected with nuclear reactors? 6. Why is uranium the main fuel for nuclear reactors? 7. What is required to start a fusion reaction?
Exercise 115. Define whether the statements are true or false.
1. Nuclear energy is produced in many different ways. 2. In nuclear fusion, the nuclei of atoms are split. 3. The Earth has unlimited supplies of coal and oil. 4. Nuclear power plants need less fuel than ones which burn fossil fuels. 5. Nuclear reactors last for about 40 years. 6. The Sun, like all other stars, creates heat and light through nuclear fission. 7. Modern nuclear reactors work on the principle of nuclear fusion. 8. Well operated nuclear power plants pollute the air.
Exercise 116. Match the beginning (column A) and the end of the sentence (column B).
| A | B |
| 1. Nuclear power is a form of energy .. | a) which burn fossil fuels. |
| 2. An energy source is a system … | b) which arises from a reaction between atomic nuclei. |
| 3. The speed in which the atomic nuclei collide … | c) endless and doesn’t give any pollution. |
| 4. In nuclear fission the nuclei of atoms are split … | d) that an atomic bomb is used to provide it. |
| 5. Nuclear power plants need less fuel than ones … | e) which causes extra pollution of the atmosphere. |
| 6. Disadvantage is that during the process of combustion a lot of toxic materials come into the air … | f) causing energy to be released. |
| 7. The advantage of alternative energy is that the energy source is … | g) is controlled by special rods. |
| 8. The heat required to start the fusion reaction is so great … | h) which makes energy in a certain way. |
Exercise 117. Fill in a missing word from those given below.