Concerned with the rapidly increasing energy needs of post-World War II European economic recovery, and particularly the possibilities presented by nuclear power, the Council of the Organisation for European Economic Co-operation (OEEC) [predecessor of the OECD] set up the European Nuclear Energy Agency (ENEA) in February 1958. The Agency’s name was changed in 1972 to the OECD Nuclear Energy Agency (NEA) to reflect its growing membership beyond Europe’s boundaries.

The first phase of the NEA's programme mainly consisted of laying the foundations for nuclear co-operation, and focused on launching several joint R&D undertakings such as the Halden and Dragon reactor projects, and the prototype Eurochemic plant for the reprocessing of spent nuclear fuels. This period came to a natural end during the late 1960s as the experimental phase of nuclear energy evolved into commercial, industrial development.

By the early 1970s the Agency's role had changed to one where major emphasis was placed on providing a forum for co-ordinating the national nuclear programmes of member countries, particularly in the health, safety and regulatory areas. As nuclear energy gathered momentum in the 1970s, governments came under increasing pressure from their constituents to give greater priority to the environmental aspects of nuclear energy and to the safety and regulation of nuclear power plants.

In the early 1990s, in the wake of the dissolution of the Soviet Bloc, the Agency followed the lead of the OECD and initiated a limited programme of outreach, focusing primarily on the countries of Central and Eastern Europe and the former Soviet Europe. Some of the activities in the outreach programme have increasingly become an integral part of the core programme of the Agency as additional countries with reactors of Soviet design have become members.

While the Agency has evolved in important ways, it has maintained the key features from which it derives its comparative advantage, including the homogeneity of its membership, its flexible working methods, the depth and quality of its technical work, and its small size and cost-effectiveness. These features will continue to be the key to the role that the Agency plays in the future, as the role of nuclear power itself evolves.