The situation changed after the Chernobyl accident of 1986 when it was seen that a nuclear accident in one country could affect the whole world. It was recognized that it is in everyone’s interest to ensure that the nuclear facilities in each country are operated to the highest standards of safety.

In the decades after the Chernobyl accident there were several international initiatives aimed at improving nuclear safety worldwide. They included the establishment of binding international conventions concerned with early notification of accidents, assistance to affected states, emergency response, nuclear safety and radioactive waste management (IAEA, 2011a). It was also recognized as desirable to strengthen the relevant international standards to encourage a more unified and rigorous approach to nuclear safety. The aim was to make the international safety standards more authoritative and, while they remained non-binding on member states of the IAEA, greater pressure was brought to bear on states to comply with the standards through the mechanisms of the international conventions, international expert safety missions, international conferences, etc. An important new element in the nuclear safety standards was the concept of ‘safety culture’ — an important lesson from the Chernobyl experience (IAEA, 1991). It means the promotion of the understanding, at all levels of management and the workforce, that safety is of fundamental importance and must be the responsibility of every individual who is involved in the activity and be incorporated within the management strategy of organizations.

The mechanisms within the IAEA for producing the safety standards were also overhauled with the objective of improving their authority in member states. The new committees responsible for approving the standards now contain top level nuclear regulators from member states. The structures of the approval committees and of the standards themselves were also changed.