The layout of nuclear power plants comprises two major parts: The nuclear island and the conventional (turbine) island. The nuclear island is the heart of the nuclear power plant. It is formed by containment building, auxiliary building, and fuel handling area. The layout of the nuclear island is specific for each nuclear power plant design. The nuclear island houses the nuclear system that produces the steam (NSSS – Nuclear Steam Supply System) and safety systems.
NSSS consist of:
- The reactor, containing the reactor core and the control systems.
- The reactor coolant pumps (RCPs) ensure the circulation of the primary coolant.
- The pressurizer (in the case of PWR) is used to control the pressure of the primary coolant.
- The steam generators (in the case of PWR), where heat is exchanged between the primary circuit and the secondary circuit.
- The primary piping.
The primary circuit can be divided into 2-6 independent loops. Each loop can comprise a steam generator and one or two pumps. The nuclear island also houses key safety systems, which mostly consist of:
- Reactor Protection Systems
- Essential service water system
- Emergency core cooling systems
- Emergency power systems
- Containment systems