The prevention and detection of and response to, theft, sabotage, unauthorized access, illegal transfer or other malicious acts involving nuclear material, other radioactive substances or their associated facilities. See: IAEA GOV/2005/50. This includes, but is not limited to, the prevention and detection of, and response to, the theft of nuclear material or other radioactive material (with or without knowledge of the nature of the material), sabotage, and other malicious acts, illicit trafficking and unauthorized transfer. The response element of the definition refers to those actions aimed at 'reversing' the immediate consequences of unauthorized access or actions (e.g. recovering material). Response to the radiological consequences that might ensue is considered part of safety. Often abbreviated to security in Agency publications on nuclear security. There is not an exact distinction between the general terms safety and security. In general, security is concerned with malevolent or negligent human actions that could cause or threaten harm to other humans; safety is concerned with the broader issue of harm to humans (or the environment) from radiation, whatever the cause. The precise interaction between security and safety depends on the context. Security of nuclear material for reasons relating to non-proliferation is outside of the scope of the Safety Glossary. Safety and security synergies concern, for example: the regulatory infrastructure; the categorization of sources; the recovery of orphan sources; emergency response plans; radioactive waste management; and safety engineering and source design. Safety matters are intrinsic to activities and transparent and probabilistic safety analysis is used. Security matters concern malevolent actions and are confidential, and threat based judgment is used