[en] Uranium exploration in Chile began in 1950, with the participation of the United States Atomic Energy Commission, the Production Promotion Corporation, the Institute of Geological Research and the Chilean Nuclear Energy Commission/Comision Chilena de Energia Nuclear (CCHEN), together with the assistance of the International Atomic Energy Agency (IAEA). In 1974 the CCHEN set up an organization for implementing the National Radioactive Resources Plan with professional staff and technicians, laboratories, equipment and supplies geared to a high technological level. This enabled the organization to carry out activities such as the provision of services to enterprises requiring them. The exploration programme started with the search for background information on which to base regional geological exploration and ended with the selection of favourable areas that deserved to be subsequently evaluated. Use was made of the conventional methods of exploration, such as aerial, geochemical, geological-radiometric, and geophysical prospecting and drilling suitably adapted to the special geological, topographic and climatic conditions of the country. During the last few years the CCHEN, in collaboration with the IAEA, prospected a total of 105,000 km², selecting an area of 5000 km² spread over 23 zones of small size for the second phase of exploration. At the same time, preliminary evaluation work has been performed on deposits of the ''exotic'' type and on veins of copper and phosphorite. (author)