Three distinct transformations of energy take place at a nuclear power plant: nuclear energy is transformed into thermal energy, thermal energy is turned into mechanical energy and mechanical energy is turned into electrical power. The heat absorbed by the coolant (modern NPPs now use mostly water) in the reactor core is converted into steam, which powers the turbine of the electric generator in the turbine room. An NPP (there are usually several reactors which are called power units) is composed of several buildings housing the appropriate technological equipment. The main building houses the reactor hall.
energybangla.com / Nuclear Asia