'Safety' is the achievement of proper operating conditions, prevention of accidents and mitigation of accident consequences, resulting in protection of workers, the public and the environment from undue radiation hazards.

'Nuclear safety' is often abbreviated to 'safety' in IAEA publications on nuclear safety. 'Safety' may thus mean 'nuclear safety' unless otherwise stated, in particular when other types of safety (e.g. fire safety, conventional industrial safety) are also being discussed.

Safety concerns the protection of people and the environment against radiation risks, and the safety of facilities and activities that give rise to radiation risks.

Safety concerns both risks under normal circumstances and risks as a consequence of incidents, as well as other possible direct consequences of a loss of control over a nuclear reactor core, nuclear chain reaction, radioactive source or any other source of radiation.

There are many different types of sources of radiation, and hence safety includes the safety of nuclear installations, radiation safety, the safety of radioactive waste management and safety in the transport of radioactive material; it does not include non-radiation-related aspects of safety.

IAEA Nuclear Safety and Security - Concepts and Terms