What are the components of a typical Nuclear Power Plant?

A nuclear power plant is a generating station which converts nuclear energy into electrical energy. The schematic diagram of a typical nuclear power station is shown in the figure. It mainly consists of the following parts −

  • Nuclear Reactor
  • Heat Exchanger
  • Steam Turbine
  • Alternator (or Electric Generator)

Nuclear Reactor

The nuclear reactor is an apparatus in which nuclear fuel such as Uranium (U235) or Thorium (Th232) is subjected to nuclear fission. The nuclear reactor controls the chain reaction which starts once the fission of the fuel is done. If the chain reaction is not controlled, the result will be an explosion due to fast increase in the energy released.

  • The nuclear reactor is a cylindrical strong pressure vessel and has fuel rods, moderator and control rods. The fuel rods are the rods of fission material such as Uranium and release huge amount of energy when bombarded with slow moving neutrons.

  • The moderator is nothing but the graphite rods which enclose the fuel rods. The moderator slows down the neutrons before they bombard the fuel rods.

  • The control rods are the bars of cadmium and these are inserted into the reactor. As the cadmium is a strong absorber of neutrons, it regulates the supply of neutrons for the fission.

  • The intensity of the chain reaction is controlled by pushing or withdrawing the control rods in the nuclear reactor.

  • In practice, raising or lowering of control rods is accomplished automatically according to the load demand.

  • The heat energy produced in the reactor is extracted out by the coolant (sodium metal) and the coolant carries the heat to the heat exchanger.

Heat Exchanger

The heat exchanger is an apparatus which utilises the heat energy of the coolant for producing the steam. After giving up the heat to the heat exchanger, the coolant is again fed to the nuclear reactor.

Steam Turbine

The steam produced in the heat exchanger is expanded in the steam turbine through the main valve which converts the heat energy of steam into mechanical energy.

After doing a useful work in the turbine, the steam is exhausted to the condenser. The condenser condenses the steam and this condensed steam is again fed to the heat exchanger with the help of a feed water pump.


The steam turbine drives the alternator which converts the mechanical energy of turbine into electrical energy.