Question: what are the three main parts of a nuclear power plant?
Answer: Fuel. Uranium is the basic fuel. ... 
Moderator. Material in the core which slows down the neutrons released from fission so that they cause more fission. ... 
Control rods. ... 
Coolant. ... 
Pressure vessel or pressure tubes. ... 
Steam generator. ... 
Containment. ... 
Nuclear power plants in commercial operation or operable.