Nuclear power plant | How does a nuclear power plant work

What Is Nuclear Power Plant

Nuclear Power plant is electrical Power generating plant in which nuclear energy is converted into electrical energy. The Nuclear energy is obtained by nuclear fission of heavy elements such as Uranium or Thorium in a special reactor called nuclear reactor. in these power plants the heat generated by the reactor, converts water into steam, which spins a turbine, which in turn rotates the generator, thus electrical energy is produced. 

Components of Nuclear Power Plant

The simple outline showing the components of nuclear power plant are shown below.

The Various components of Nuclear Power plant are

1. Nuclear Reactor.
2. Heat Exchanger ( or Steam generator)
3. Steam Turbine 
4. Condenser
5.  Electric Generator ( or Alternator)

Nuclear Reactor: Nuclear reactor is the main component of nuclear power plant. The main function of the nuclear reactor is control nuclear chain reactions that produces heat by nuclear fission reaction- the process in which a heavy atomic nucleus splits into two smaller fragments. The fuel in the nuclear reactor are Uranium-235, Uranium-233 and Plutonium-239. Uranium-233 and Plutonium-239 can be produced artificially from Uranium-238 and Thronium-232 which occur in nature and are called fertile materials. \\\;\\\;\;\;\;U^{238}+n^{1}\rightarrow U^{239}+\gamma\\\;\\\;\;\;\;U^{239}\rightarrow Np^{239}+e\\\;\\\;\;\;\;Np^{239}\rightarrow Pu^{239}+e

In reactor chain reaction is controlled by control rods. The material used for the control rods have high absorption capacity for neutrons. The common material used for control rods are cadmium, boron or hafnium.\\Reactor is enclosed in a shield. Material for Shield is concrete. Addition of Boron compounds in concrete helps in arresting neutrons and secondary radiations.

Heat Exchanger (or Steam Generator): The coolant after receiving heat in the Nuclear reactor, temperature of the coolant increases. The hot coolant after leaving the Nuclear reactor flows through the tubes of Heat Exchanger, and passes its heat to water and water gets converted into steam. After giving up heat, the coolant is again fed to the reactor. The coolant commonly used are gas ( CO₂, air, hydrogen, helium ), Water, heavy water, liquid metals (Sodium or Sodium potassium ) etc. 

Steam Turbine:  The steam produced in the heat exchanger is fed to the steam turbine, where it rotates the turbine. Thus heat energy of steam is converted into mechanical energy. The steam turbine in-turn rotates the alternator and electrical energy is produced. 

Condenser: After doing a useful work in the turbine, the steam is exhausted to condenser. The condenser condenses the steam which is fed to the heat exchanger through feed water pump.

Salient features of Nuclear Power Plant

The various salient features of nuclear power plant are

1. Site should be located near load center and nuclear fuel should be easily transported. There should be availability of water and space for burial of radio-active material.
2.  Initial cost of material is moderate.
3. Cost of fuel is low.
4. Skilled and well trained staff is required to handle the equipments.
5. Running cost is low as compared to thermal power plant.
6. It is used for base Load

Advantages of Nuclear Power Plant

The various advantages of Nuclear Power Plant are

1. It is pollution free. Produces no polluting gases.
2.  It is most Reliable Energy Source. Nuclear power plants run 24 hours a day, 7 days a week. They are designed to operate for longer stretches and refuel every 1.5 – 2 years. In 2019, nuclear plants operated at full power more than 92% of the time, making it the most reliable energy source on the grid today.
3. It has Very low fuel costs as compared to thermal power Plant.
4. These Power station has very long lifetime.

Disadvantages of Nuclear Power Plant

The various disadvantages of Nuclear Power Plant are

1. Safe disposal of radioactive material is difficult and expensive.
2. Local thermal pollution from wastewater affects marine life.
3. Costs of building and safely decommissioning are very high.
4. Cannot react quickly to changes in electricity demand.
5. The efficiency of nuclear power Plant is less than thermal power plant because of low operating temperature and pressure conditions. 

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