Main features of nuclear power plants with PWR-type (Pressurized Water Reactor) reactor.
As you can see the nuclear power plant consist of two main buildings:
The containment building is the key building of the nuclear island. It is an air-tight building, which houses a nuclear reactor and its pressurizer, reactor coolant pumps, steam generators, and other equipment or piping that might otherwise release fission products to the atmosphere in the event of an accident. Such buildings are usually made of steel-reinforced concrete.
The turbine building is the key building of the conventional (turbine) island. The turbine building houses a turbine, generator, condenser and other equipment, which is used for conversion thermal energy from pressurized steam to mechanical work used for drive the generator.
Also a cooling tower can be part of the nuclear power plant, but it is not necessary. Many nuclear power plants (coastal nuclear power plants) do not cool the cooling water via cooling towers.