The uranium found in its natural form does not produce energy. The enrichment process is used to separate and increase the concentration of one of its atoms which undergoes fission process in the cores of nuclear reactors.

The uranium enrichment technology was developed in Brazil by the Navy Technological Center in São Paulo (CTMSP), in partnership with the Institute of Energy and Nuclear Research (IPEN / CNEN). INB produces uranium enriched to 4% for the production of fuels that feed the plants Angra 1 and Angra 2 and that will also feed Angra 3 in the future.

The enrichment process used by the company is the ultracentrifugation. The enrichment facility is being implemented in stages in the Nuclear Fuel Factory (FCN), located in Resende, Rio de Janeiro. Part of the enriched uranium is still imported. In October, 2015, the FCN Enrichment Plant reached the capacity to produce about 14% of the annual average amount of enriched uranium needed to fuel the reactor Angra 1 and Angra 2.

When the implementation is complete, Brazil will be self-sufficient in the production of the material. It is expected that this will occur in 2022, when the Plant Enrichment of FCN should be able to produce 35 tonnes of enriched uranium annually.

Uranium enrichment in Brazil is supervised by three institutions: International Atomic Energy Agency (AIEA), National Nuclear Energy Commission (CNEN) and Agency Brazil - Argentine Agency for Accounting and Control of Nuclear Materials (ABACC).