Abstract: A nuclear power station has a containment in which a reactor core is accommodated. According to the invention, an external cooling system for cooling the containment in the event of an accident is associated with the containment. The cooling system in particular has a coolant reservoir that is configured as a lake or is lake-like, and in which the containment is in contact with a coolant or may be brought into contact with a coolant, in particular a liquid coolant, in the event of an accident.