What is Nuclear Power Plant?
- Nuclear power plant is similar to thermal or steam power plant; the only difference is that, the boiler of steam power plant is- replaced by nuclear reactor.
- Nuclear power plant utilises nuclear energy produced by nuclear reactions for generation of steam.
- The heat is produced by nuclear fission of the atoms of fissionable material and it is utilised in special heat exchangers for the production of steam.
- The commonly used nuclear fuels are unstable atoms like Uranium (U235), Thorium (Th232) and artificial element plutonium (Pu239).
- These unstable atoms liberate large amount of heat energy. The energy released by the complete fission of 1 kg of U235 is equal to the heat energy obtained by burning 4500 tonnes of coal or 2200 tonnes of oil.
- But there are some limitations in the use of nuclear energy like high cost of plant set-up, limited availability of raw materials, problem with disposal of radioactive waste and highly skilled operators.
- Due to these reasons, nuclear power plants are still developing in India. Only 1% to 3% energy requirement is fulfilled by nuclear power plant in countries like India, whereas in France about 30% of its energy requirement is generated by nuclear method.
- The general layout of nuclear power plant is shown in Figure.
- The function of various elements of nuclear power plant is as follows:
1. Nuclear reactor
2. Heat exchanger
3. Steam turbine
4. Generator
5. Condenser
6. Feed pump
7. Feed water heater
8. Coolant pump
1. Nuclear reactor
In the nuclear reactor, nuclear energy is produced by the nuclear fission of unstable atoms like uranium. Uranium is in the form of thin rods or plates. This energy is transferred to the circulating coolant.
2. Heat exchanger
The heat exchanger will act as a boiler for the power plant, The heat absorbed by reactor is transferred to the water and steam generated. Generally, U-tube type heat exchanger is used. The commonly used coolants are carbon dioxide, helium, liquid metals like sodium potessium, etc.
3. Steam turbine
It converts high pressure and high temperature steam supplied by the heat exchanger into shaft work and low temperature steam is exhausted to a condenser.
4. Generator
The mechanical energy of steam turbine is converted into electrical energy with the help of generator.
5. Condenser
Steam exhausted from steam turbine is collected in the condenser and condensed by using recirculated cooling water.
6. Feed pump
The collected amount of condensate is again fed back to the heat exchanger with the help of feed pump.
7. Feed water heater
The water pumped from feed pump is initially heated in the feed water heater and then supplied to the heat exchanger.
8. Coolant pump
The coolant after transferring the heat in the heat exchanger is again fed back to the nuclear reactor with the help of coolant pump.
Advantages of Nuclear Power Plant
- The cost of generated power is less than the thermal power plant.
- There is no problem of environmental pollution, fuel transportation, mine safety, etc.
- Nuclear power plant does not require fossil fuels like coal, coke, natural gas which can be used in other areas.
- Less space is required as compared to steam power plant.
- Large amount of energy is generated by burning small amount of fuel.
Disadvantages of Nuclear Power Plant
- Initial cost of plant set-up is high.
- Nuclear reactor fuels are not easily available.
- There is problem of disposal of radioactive waste.
- For the operation of power plant highly skilled operator is required.
- Cost of nuclear reactor fuels is also high.
- During the operation, nuclear radiations are produced hence high degree of safer?’ is required for the operators.
FREQUENTLY ASKED QUESTIONS?
Q.1. Explain nuclear power plant and why are these plants less in India?
Q.2 Explain nuclear Power plant and its working.
Q.3 State the advantages and disadvantages of nuclear power plants.