A nuclear power plant is a thermal station whose heat source is a nuclear reactor. As with thermal stations, the heat generated is used to produce steam which is used to drive a turbine. The turbine is connected to a generator which produces electricity. As the turbine rotates, it drives the generator that produces electricity. As of today there are 31 countries that use nuclear power to produce electricity and more countries are expected to build their own nuclear power plants in future. Nuclear power plants are considered less expensive to maintain due to the low fuel cost, but initial capital cost for construction of these plants is usually very high.
The conversion to electrical energy usually takes place indirectly. The fission process in the reactor heats the reactor coolant. The coolant may be water, gas or liquid metal, depending on the type of reactor. The coolant then goes to the steam generator and heats water to produce steam. The high pressure steam is then fed to the steam turbine. As the steam impacts on the turbine blades, the turbine rotates and acts as a prime mover to the generator and the generator produces electricity.
The Nuclear Reactor
It is the heart of the station. The reactor’s core produces heat by nuclear fission and this heat increases the temperature of the coolant as it is pumped through the reactor to reduce its temperature. The heated coolant is then transferred to the steam generator where it converts the water to steam. This steam is used to drive the turbine which acts on the generator to produce electricity. After the steam turbine has expanded and partially condensed the steam, the steam is passed to a condenser where it is condensed. The condensate is then pumped back into the steam generator to begin the whole cycle again. Nuclear reactors employ uranium to fuel the fission process. Uranium is a heavy metal found on earth, in sea water and rocks. Since nuclear fission creates radioactivity the reactor core is surrounded by a protective shield. This shield absorbs radiation and prevents radioactive materials from being released into the environment. Many reactors are also protected by dome of concrete to protect against internal impact and external casualties.