Just as many thermal Power Stations generate elecetricity by harnessing the thermal energy eleased from burning fossil fuel. Nuclear Power Plants convert the energy from the nucleus of an atom. Typically via nuclear fission.
A typical nuclear reactor has a few main parts. Inside the core where the nuclear reaction takes place are the fuel rods and assemblies, the control rods the moderator and the coolant. Outside the core are the steam generator, turbines & parts of the cooling system.
The job of the coolant is to absorb the heat from the reaction. The most common coolant used in nuclear power plant today is Water. The coolant water is heated by the nuclear reactions going on inside the core. However this heated water does not boil because it is kept at an extremely intense pressure, thus raising its boiling point above the normal 100 celcius.
The heated water rises up and passes through another part of the reactor, the heat exchanger. The moderator/coolant water is radioactive, so it can not leave the inner reactor containment. Its heat must be transferred to non-radioactive water, which can then be sent out of the reactor shielding. This is done through the heat exchanger, which works by moving the radioactive water through a series of pipes that are wrapped around other pipes. The metallic pipes conduct the heat from the moderator to the normal water. Then, the normal water (now in steam form and intensely hot) moves to the turbine, where electricity is produced.
After the hot water has passed through the turbine, some of its energy is changed into electricity. However, the water is still very hot. It must be cooled somehow. Many nuclear power plants used steam towers to cool this water with air. These are generally the buildings that people associate with nuclear power plants. At reactors that do not have towers, the clean water is purified and dumped into the nearest body of water, and cool...