Аврамова NUCLEAR ENGLISH 2013

Exercise 2. Match the two parts of the sentences. Look at Reading 4-A to help you.

1.Nuclear fission is a nuclear reaction...

2.If it occurs without neutron bombardment, as a type of radioactive decay, ...

3.However, most nuclear fission occurs as induced fission in a nuclear reactor...

4.This makes possible a self-sustaining chain reaction...

5.The isotopes that can sustain a fission chain reaction...

6.Uranium 235 is one of the few materials …

7.The energy released by a single fission comes from the fact that the fission products and the neutrons …

8.The difference in weight is converted directly to energy …

A. ... as a result of the bombardment of heavy nuclei by neutrons.

B.… at a rate given by Einstein’s equation E = mc2.

C.…weigh less than the original U-235 atom.

D. ... in which the nucleus of a heavy atom splits into lighter atoms, producing free neutrons and large amounts of energy.

E. ... that releases energy at a controlled rate in a nuclear reactor or at a very rapid uncontrolled rate in a nuclear weapon.

F. ... are called nuclear fuels, and are said to be fissile or fissionable. G. ... this type of fission is called spontaneous fission.

H. … that can undergo induced fission.

Exercise 3. Use Reading 4-A to find the English equivalents for the following Russian phrases.

Ядро – ядра – ядерная реакция; делиться на более легкие атомы, делящееся ядро, деление атома; радиоактивный распад; спонтанное деление, контролируемое деление; поддерживать цепную реакцию, самоподдерживающаяся цепная реакция; заставлять ядро делиться, вызвать дальнейшее деление; ядерное топливо, делящиеся материалы, подвергаться спонтанному делению (делиться спонтанно), период полураспада, природный уран, поглощать нейтрон, выделять огромное тепло, обогащать – обогащенный уран – обогащение, оружейный уран.

Exercise 4. Give the derivatives of the words below. 1. To heat – тепло, отопление.

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2.To weigh – вес.

3.To fission – деление, делящийся, способный к делению.

4.To collide – столкновение.

5.To bombard – бомбардировка.

6.To induce – индукция, индуцированный.

7.To cause – причина, потому что, из-за.

8.To absorb – поглощение.

9.To equal – равный, уравнение.

10.To remain – оставшаяся часть, остаток.

11.To convert – преобразование, преобразователь, обратимый.

12.To contain – содержание.

13.To compose – состав, разлагать.

14.To live – жизнь, период полураспада.

15.Possible – невозможный, возможность.

Exercise 5. Use Reading 4-A to answer the questions below:

1.What is nuclear fission?

2.What is meant by spontaneous fission? Induced fission?

3.What causes the atom to split in a nuclear reaction of fission?

4.What makes the self-sustaining chain reaction possible?

5.In what two ways can the chain reaction release energy?

6.What is meant by fissile/fissionable materials?

7.What are the two most common uranium isotopes?

8.How does U-238 behave and what is it finally transformed into?

9.What is the proportion of U-238 to U-235 in nature?

10.Why is U-235 the most important of all the uranium isotopes? 11.How much energy does the splitting of a U-235 atom release? 12.Where does this energy come from?

13.What is required for the fission reaction to occur in a nuclear reactor?

14.What enrichment is required for a NPP? For weapons-grade uranium?

Reading 4-B

Emission of Neutrons

Neutrons are ideal projectiles for nuclear bombardment because they have nо electrical charge and thus suffer no repulsion when they approach atomic nuclei. They are usually divided into thermal and fast neutrons according to their energy.

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A thermal neutron is a neutron with a relatively low energy of less than 1 MeV, and a speed of 2.2 km/s. Fast neutrons are fast! A fast neutron is a neutron with a kinetic energy close to 2 MeV, and a speed of 28,000 km/s. Fast neutrons can be made into thermal neutrons using a process called moderation. This is done with a neutron moderator. Most fission reactors use a neutron moderator to slow down the fast neutrons so that they are more easily captured, causing further fission. In reactors, heavy water, light water, or graphite is used to moderate neutrons.

The neutrons emitted as a result of the fission process can be divided into two categories, namely, prompt and delayed neutrons. The prompt neutrons are over 99 percent of the total fission neutrons. They are released within an extremely short interval of time, about 10-14 sec, of the fission process. Prompt neutrons are emitted directly by the fissioning nuclei. The delayed neutrons are produced by the decay of fission products and are emitted with a delay of a few seconds. The delayed neutrons are of great importance. They keep the chain reaction from developing into an uncontrolled process. Hence, they enable the reactor operation to be controlled.

Exercise 1. Match the two parts to make expressions from Reading 4-B. Read the text again if necessary.

Now complete these sentences using the expressions above.

1.Neutrons are _______ for ______ because they have nо electrical charge.

2.Most fission reactors use a ______ to slow down the fast neutrons so that they are more easily captured, causing further fission.

3.The _______ are produced by the decay of ______ and are emitted with a delay of a few seconds.

4.The delayed neutrons keep the chain reaction from developing into an _______.

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Exercise 2. Use Reading 4-B to find the English equivalents for the following Russian phrases.

Бомбардирующая частица, отталкивать – испытывать отталкивание, быстрые и тепловые нейтроны, замедление – замедлитель нейтронов, замедлять (быстрые) нейтроны, захватывать нейтроны, мгновенные и запаздывающие нейтроны, испускать/излучать нейтроны, продукты деления, распад, задержка в несколько секунд, управлять работой реактора.

Exercise 3. Use Reading 4-B to answer the questions below.

1.Why are neutrons ideal projectiles for nuclear bombardment?

2.What is the difference between fast and thermal neutrons?

3.Into what two groups can fission neutrons be classified?

4.What is meant by “prompt” neutrons?

5.What is meant by “delayed” neutrons?

6.Why are delayed neutrons so important for fission reactors?

Reading 4-C

A Walk in the Snow

You are going to read a passage about the discovery of fission. Five sentences have been removed from the text. Choose from the sentences A-F the one which fits each gap (1-5). There is one extra sentence which you will not need to use.

A.Under the bombardment of neutrons, the uranium nuclei were splitting.

B.It was Frisch who introduced the term “fission”.

C.To his surprise, he only succeeded in producing isotopes of barium (Z=56).

D.But Meitner never received the Nobel Prize for her work.

E.He didn't know how the results of his research would be used.

F.In Germany in 1938, Otto Hahn was studying the effect of irradiating heavy elements with neutrons.

Who was the first to discover that heavy nuclei could undergo fission? 1).____________ He hoped the heavy nuclei would absorb the

neutrons, creating “transuranic elements”. These have a higher atomic number than uranium, with more than 92 protons in their nuclei (expressed as Z=92). 2)._________

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Hahn wrote to one of his colleagues, Lise Meitner, to tell her about his curious finding. Meitner was a Jew and had to leave Nazi Germany to live in Sweden. During a walk in the snow with her nephew, the nuclear physicist Otto Frisch, she realized the importance of Hahn’s discovery. 3)._________ If barium (Z=56) was being produced, then so much krypton (Z=36), since 36+56=92. It soon became clear that this is not the only pair of nuclei that can be produced. Another possible pair is rubidium (Z=37) and caesium (Z=55). 4).________ And it was Meitner who suggested that it releases energy.

A Nobel Prize was a suitable reward for the discovery of nuclear fission, and Hahn was awarded the chemistry prize for the work in 1944. 5)._________ It was a strange mistake that has provoked a lot of discussion among nuclear scientists.

Reading 4-D

Architect of the Nuclear Age

Read the passage about the famous Italian physicist Enrico Fermi and answer the question: What role did Fermi play in the American atomic bomb project?

Enrico Fermi discovered physics at the age of 14 and by 32 had developed the theory of beta decay. То explain it he had to introduce the fourth fundamental force of the universe, now known as Fermi’s ‘weak force’, the other three forces being gravity, electromagnetism and the strong force.

In 1934, Fermi and his team conducted а series of experiments that involved bombarding atomic nuclei with neutrons, and obtained many new isotopes. As a by-product, they found that slowing down neutrons by passing them through paraffin increased their effectiveness. That was the most important discovery of his life, as it would allow the controlled release of nuclear energy in а reactor. For these two discoveries, Fermi was awarded the Nobel Prize in1938.

In 1934 he had missed another Nobel Prize discovery - nuclear fission. The foil in which the uranium samples had been wrapped during experiments was too thick and the instruments were not sensitive enough to record the fission fragments. It was а blessing in disguise

(something that at first appears to be bad or unlucky but is actually

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good – «нет худа без добра»). If fission had been discovered then, Nazi Germany would have built an atomic bomb.

In 1939 Fermi immigrated to the USA in order to save his Jewish wife Laura from anti-Semitic persecution in Mussolini’s Italy. Many Jewish scientists had to leave Nazi Germany for the same reason. Historians agree that if Hitler had not forced Jewish scientists to leave Europe, he might have got the atomic bomb before America. Fermi and other famous scientists who had left Europe, including Leo Szilard, John von Neumann, Edward Teller and Hans Bethe played an important role in the American nuclear story.

In 1942, at the head of the multi-national research group, Fermi produced the first controlled, self-sustaining chain reaction. When in 1949 President Truman initiated the program to develop the hydrogen bomb, Fermi strongly opposed it. ‘It is clear that such а weapon cannot be justified on any ethical ground... The fact that no limits exist to the destructiveness of this weapon makes its very existence and the knowledge of its construction а danger to humanity as а whole,’ he wrote.

His warnings were ignored. The Cold War arms race between America and the Soviet Union put the world at mortal risk. But there is no doubt that the discovery of controlled nuclear energy, in which Fermi’s role was so crucial, did have long-term beneficial results: a potentially unlimited source of energy and keeping humanity from another world-scale war.

Exercise 1. Read the text again and answer the following questions.

1.What are Fermi's main contributions to nuclear physics?

2.Fermi and his group nearly made one more important discovery. What was it? Why did they fail?

3.What was Fermi's attitude to the hydrogen bomb program?

Exercise 2. Suggest explanations for the following facts mentioned about Enrico Fermi in Reading 4-D.

1.He failed to discover nuclear fission. This fact is called «a blessing in disguise».

2.He was an Italian but lived and worked in the USA.

3.He played a crucial role in the development of the A-bomb but was against the H-bomb program.

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Exercise 3. Match the following Russian and English equivalents.

Exercise 4. Re-write the sentences and replace the underlined parts with the words or phrases listed below.

Chain reaction, mortal danger, crucial, arms race, release, nuclear fission, beneficial, long-term effects

1.A competition between industrial countries to produce more and deadlier weapons is a waste of human and material resources which otherwise might be put to more beneficial uses.

2.Some specialists say that no matter how costly modern research may be the favorable and useful effects by far outweigh the costs.

3.Few specialists could predict the effects of the scientist's discoveries in the distant future.

4.The discovery of nuclear fission was of great importance for humankind in the 20th century.

5.On August 6, 1945, humankind became aware of the danger of complete destruction caused by nuclear weapons.

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6.One free neutron can lead to the liberation of two or three; that makes the extraction of energy in useful quantities from the process of splitting the nucleus of certain atoms into parts possible.

7.The released neutrons can start a number of related changes in the

fissile material, each of which causes the next, but it can also die out quickly if there is not enough U235, i.e., no critical mass of fissile material.

Exercise 5. Read the last sentence in Reading 4-D again. Think about the questions below and write your answers to them.

1.According to the author, how did the developments in nuclear physics in the 20th century affect the humanity?

2.Do you agree with him? Why? Why not?

Reading 4-E

Nuclear Scientists and the Nuclear Bomb

Look through these encyclopaedia entries about four scientists and say what they have in common. Why do you think these scientists took part in the nuclear projects?

Hans Bethe – a German physicist who went to the USA to escape the Nazis in 1935, discovered the fusion reactions that power the stars, directed work on the first A-bombs and contributed to the H-bomb. At the same time he strongly opposed nuclear testing and the nuclear arms race.

J. Robert Oppenheimer – an American physicist who headed the atom bomb project known as the Manhattan Project. He directed the Los Alamos laboratory that created the first A-bombs and made a considerable contribution to the post-war nuclear arms race. Because of his opposition to the US H-bomb program he was tried and lost his security clearance (допуск к секретным материалам) in 1954.

Edward Teller – a Hungarian nuclear physicist who emigrated to the US in 1935. He was known as the father of the H-bomb and never expressed any doubt about it. Because of his fear of Russia he supported

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the US H-bomb program after the first Soviet A-bomb test. Later he became an enthusiastic supporter of the US Star Wars program.

Andrey Sakharov - as a young Soviet physicist he was ordered by the KGB to work on the H-bomb and designed a kiloton weapon that exploded in 1955, only 13 months after the first US H-bomb test. He is regarded as the father of the Soviet hydrogen bomb. In the 1960s, he opposed nuclear proliferation and protested against atmospheric testing of the hydrogen bomb. In 1975 he became the first Russian to win the Nobel Peace Prize.

Do you know?

The Manhattan Project (1939 – 1945) was the top-secret plan to develop the world's first atomic bomb in the United States.

With the discovery of fission in 1939, it became clear to scientists that certain radioactive materials could be used to make a bomb of great power. At the beginning of World War II, news arrived in the U.S. that the Nazis were making an atomic bomb. The U.S. believed they could not allow the Nazis to build such a powerful weapon first and started the Manhattan Project to design a nuclear weapon. In 1942 Enrico Fermi and his associates achieved the first controlled nuclear fission reaction. In 1945 their work resulted in the first test of a nuclear weapon called «Trinity» which was a plutonium device.

The first uranium bomb (“Little Boy”) was dropped on Hiroshima on

August 6, 1945, killing at least 70,000 people. On August 9, 1945, a plutonium bomb (“Fat Man”) identical to the Trinity device was dropped on Nagasaki, killing at least 35,000 people.

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Unit 5

Reading 5-А

Nuclear Reactor Primer

The paper-moderated, ink-cooled reactor is the safest of all.

Read Passage 1 and answer the questions below:

1.How much nuclear electricity did nuclear reactors produce worldwide as of July 2008?

2.Which country depends on nuclear power most?

3.In what way do nuclear power plants differ from conventional plants?

4.What are the principal categories of nuclear reactors?

5.How can you account for the difference between them?

1.Nuclear Power in the World Today

As of July 2008, there were more than 430 operating nuclear power plants in 31 countries and, together, they provided about 15 percent of the world’s electricity in 2007. Some countries depend more on nuclear power than others. For instance, in France about 77 percent of the country's electricity comes from nuclear power. In the United States, 104 nuclear power plants supply 20 percent of the electricity overall. In Russia, 31 nuclear power plants supply 16 percent of the country's electricity.

Actually, a nuclear power plant does not operate differently from a conventional power plant. Both heat water into steam, which drives a turbine generator. The main difference between the two plants is the method of heating the water. While conventional plants burn fossil fuels, nuclear plants derive the heat from nuclear fission, when one atom splits into two.

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