A nuclear power plant is a complex technological facility containing many types of radioactive material. Safety is therefore a very important aspect of nuclear power plants. In principle, nuclear safety means the minimization of the possibility of a nuclear accident, whether due to a hardware malfunction or human error. Compliance with safety regulations regarding the operation of nuclear facilities and the handling of nuclear material is under the control of the national nuclear safety authority, but also of international organizations, headed by the International Atomic Energy Agency. In case of a nuclear power plant accident, the public must by informed truthfully and promptly.