A list of active words and expressions

thermal/breeder reactor	– тепловой/бридерный реактор
to absorb	– поглощать
to convert smth. into smth.	– превращать в
to consume	– потреблять
predominant	– преобладающий
development	– развитие, разработка
Thorium (Th)	– торий
Plutonium (Pu)	– плутоний
to use (employ, apply)	– использовать, применять
BWR	– реактор с кипящей водой
PWR	– реактор с водой под давлением
HTGR	– высокотемпературный газоохлаждаемый реактор

Ex. 1. Fill in the blanks.

1. Nuclear reactors ... into two broad classes. 3. ... reactors use only U-235. 4. The thermal reactors have ... to slow down ... neutrons. 5. The thermal reactors can use … water, carbon or … water as a moderator. 6. There are two different ... systems. 7. The fast breeder reactors ... U-238 ... Pu-239. 8. The fast breeder reactors can produce more fuel than they … it. 9. Non-productive absorption of neutrons is less in ... reactors. 10. The general ... in the future ... of nuclear power in Russia is towards … of the fast breeder reactors.

Ex. 2. Translate from Russian into English.

1. производить свое собственное топливо

2. использовать полностью все топливо

3. обычная/тяжелая вода

4. делить на основные категории

5. иметь преимущества над

6. преобразовывать U-238 в Pu-239

7. использовать U-235 в качестве топлива

8. поглощать нейтроны (поглощение)

9. уран, плутоний, торий, углерод

10. главное направление

Ex. 3. Learn the dialogues.

1. – What are the two basic classes of nuclear reactors?

– They are thermal reactors and fast neutron reactors.

– What is the difference between them?

– The thermal reactors employ slow neutrons and uranium U-235 as the fuel. They also use a moderator to slow down fast neutrons.

– And what about the fast breeders?

– The breeder reactor is a reactor that can produce more fuel than it consumes. It converts U-238 into Pu-239 and employs fast neutrons.

2. – What types of thermal reactors do you know?

–The thermal reactors can be subdivided into boiling-water reactors, pressurised-water reactors, CANDU, high-temperature gas-cooled reactors and the water-cooled graphite- moderated channel type reactors.

– What reactor types are predominant in our country?

– They are water-cooled graphite-moderated channel type reactors and water-cooled water-moderated reactors of the PWR type.

Ex. 4. Answer the following questions.

1. What are the principal categories of nuclear reactors?

1. What thermal reactor types do you know?

1. What is the principal difference between the thermal and fast neutron reactors?

1. What are the advantages of the fast breeder reactors?

2. What is the general trend in the future development of nuclear power?

Ex. 5. Speak about the reactor types.

UNIT VIII

Text safety of nuclear reactors

The safety of nuclear power plants has been of great importance from the very beginning of the development of nuclear reactors. But it has become the focus of the international nuclear community since the Chernobyl accident in1986. Modern standards of nuclear safety ensure reliable operation of all systems at any plant dealing with radioactive materials.

Though the strict safety measures are provided at any nuclear installation, there are some difficulties that have to be faced. There is still a popular fear in the public mind associated with the radiation. The tragic consequences of the most serious reactor malfunctions and accidents are the main reasons for this.

The most widely discussed type of a reactor malfunction is the loss-оf-coolant accident (LOCA). A typical LOCA means a pipe leak, which results in sudden depressurization of the pressure reactor vessel. The water begins to boil, so it makes the core heat up instead of cooling. This can cause the core melting. The destroyed core is able to release a catastrophic amount of radioactive products into the biosphere.

Thus, the essence of reactor safety is to protect the environment from the dispersal of radioactivity. The key to safer nuclear power is a more efficient emergency core-cooling system (ECCS) and a more reliable containment building.

There are some other problems associated with the reactor safety. They are human errors in critical situations and the disposal of nuclear waste.