Text 4 nuclear power plant

The heart of the nuclear power plant is the reactor which contains the nuclear fuel. The fuel usually consists of hundreds of uranium pellets placed in long thin cartridges of stainless steel. The whole fuel cell consists of hundreds of these cartridges. The fuel is situated in a reactor vessel filled with a fluid. The fuel heats the fluid and the super-hot fluid goes to a heat exchanger i.e. steam generator, where the hot fluid converts water to steam in the heat exchanger. The fluid is highly radioactive, but it should never come into contact with the water that is converted into steam. Then this steam operates steam turbines in exactly the same way as in the coal or oil fired power-plant.

A nuclear reactor has several advantages over power-plants that use coal or natural gas. The latter produce considerable air pollution, releasing combusted gases into atmosphere, whereas a nuclear power plant gives off almost no air pollutants. As to nuclear fuel, it is far cleaner than any other fuel for operating a heat engine. Furthermore, our reserves of coal, oil and gas are decreasing so nuclear fuel is to replace them.

Text 5 Electronics and Technical Progress

Large – scale application of electronic techniques is a trend of technical progress capable of revolutionizing many branches of industry.

Electronics as a science studies the properties of electrons, the laws of their motion, the laws of the transformation of various kinds of energy through the media of electrons.

At present it is difficult to enumerate all branches of science and technology which are based on electronic technique.

Electronics make it possible to raise industrial automation to a higher level, to prepare conditions for the future technical retooling of the national economy. It is expected to revolutionize the system of control over mechanisms and production processes. Electronics greatly helps to conduct fundamental research in nuclear physics, in the study of the nature of matter, and in realization of controlled thermonuclear reactions.

An ever greater role is being played by electronics in the development of the chemical industry.

Electronics embrace many independent branches. The main among them are vacuum, semiconductor, molecular and quantum electronics.

Text 6 Protection and control equipment

In electrical systems for the generation, distribution and use of electrical energy, considerable control equipment is necessary. It can be divided into two classes:

a) equipment used at the generating and distributing end;

b) equipment used at the receiving end of the system.

c) secondary emission, in which electrons are driven from a material by the impact of electrons or other particles on its surface.

d) field emission, in which electrons are drawn from the surface of a metal by the application of very powerful electric fields.

Text 7 The Nucleus

The nucleus is composed of protons, neutrons, and other subatomic particles. The proton is a relatively heavy positive particle. It has exactly the same quantity of electrical charge as the electron although its sign (or value) is opposite. The proton weighs the same as approximately 1845 electrons, and the atom contains a like number of protons and electrons. The neutron is so named because it is electrically neutral, that is, it is neither positive nor negative. The neutron adds weight to the atom and tends to prevent movement of the protons.

When the parts of the atom are examined, there can be found minute particles with positive and negative electrical charges. The basic difference between lead and gold lies in the number of electrons and protons in the atoms which compose these materials (metals).

The simplest atom consists of a nucleus which contains one proton, which is orbited by a single electron. This is the hydrogen atom. One of the more complex atoms is californium. This atom contains 98 photons and 98 electrons with the electrons orbiting the nucleus in seven different and distinct energy shells.