Electricity From Nuclear Energy
Nuclear Power Plant and it’s Working
The heat produced in a controlled fission can be used for producing electricity. The set–up used for generating electricity from the heat released in a controlled nuclear fission is called a nuclear power plant or nuclear power station. The heat produced in a controlled nuclear fission is used for producing steam. The steam so produced runs the turbine. The rotatory motion of the turbine rotates the alternator of the generator and the electricity is produced. Thus, in a nuclear power plant the energy transforms in the following sequence :
Nuclear energy of uranium–235 nucleus → Heat energy of steam → Kinetic energy of turbine → Kinetic energy of the alternator → Electrical energy
Components of a Nuclear Power Plant
A nuclear power plant consists of the following components :
Nuclear reactor : Here, a controlled nuclear fission of a fissionable fuel such as is carried out.
Heat exchanger : The reactor is connected to heat exchanger. Here, the heat produced in the reactor is transferred to water by circulating a coolant through a coiled pipe. The water gets converted into steam. The coolant is pumped back to the reactor.
Steam turbine : The steam generated in the heat exchanger is used to run the steam turbine. The spent steam is sent back as hot water to the heat exchanger.
Electric generator (or dynamo) : The shaft of the steam turbine is connected to an electric generator (or dynamo). Electricity so produced is sent for transmission.
Location of Power Station in India
At present about 3% of the electrical energy produced in India is obtained from nuclear power stations (also called atomic power stations).
The following atomic stations are in operation in India :
Tarapur atomic power station (420 MW) in maharashtra.
Rajasthan atomic power station (440 MW) at Rana Pratap Sagar near Kota in Rajasthan.
Madras atomic power station (420 MW) at Kalpakkam in Tamil Nadu.
Narora atomic power station (470MW) near Bulandshahar in Uttar Pradesh.
Sun”The Ultimate Source of Energy
The source of the large amount of solar energy is due to fusion of lighter nuclei. About 90 percent of the solar mass is composed of hydrogen and helium and rest 10 percent contains other elements. The temperature of the interior of the sun is estimated to be about 2 × 107K.
The nuclei of hydrogen fuse together in the sun’s interior to produce helium and a huge amount of energy is released. It is estimated that 1g of hydrogen produces 620,000 million joules of energy.
The fusion process in the sun can be described by the equation.
Destructive form of nuclear energy
Nuclear bomb produces tremendous amount of destructive energy. This energy is produced by uncontrolled nuclear fission chain reaction.
The atom bomb or nuclear bomb produces large amount of energy when two pieces of uranium (235U) or Plutonium (239Pu) are brought in contact so that the total mass become greater then critical mass.
During this process a very high temperature of the order of million degree kelvin is produced and also a very high pressure of the order of several million atmosphere is developed.
Hydrogen bomb produces extremely high destructive energy by using nuclear fusion. The fusion reaction is performed over heavy–hydrogen nuclei at very high temperature and pressure.
To get this high temperature and pressure, nuclear fission bomb is used at the centre core of a hydrogen bomb which is formed of heavy hydrogen like lithium hydride (LiH2).
Exploiting any source of energy disturbs the environment in some way or the other. In any given situation, the source we would choose depends on factors such as the ease of extracting energy from that source, the economics of extracting energy from the source, the efficiency of the technology available and the environmental damage that will be caused by using that source. Research continues in these areas to produce longer lasting devices that will cause less damage throughout their life.
Saving energy resources
we cannot depend on the fossil fuels for much longer. Such sources that will get depleted some day are said to be exhaustible sources or non-renewable sources of energy. On the other hand, if we manage bio-mass by replacing the trees we cut down for fire-wood, we can be assured of a constant supply of energy at a particular rate. Such energy sources that can be regenerated are called renewable sources of energy.
Renewable energy is available in our natural environment, in the form of some continuing or repetitive currents of energy, or is stored in such large underground reservoirs that the rate of depletion of the reservoir because of extraction of usable energy is practically negligible.