During the 1930s and 1940s, Brazil signed agreements with the United States exchanging monazite, a radioactive ore that can be used as a replacement for uranium in nuclear power generation, for nuclear technology. In the late 1950s, Brazil embarked on an independent nuclear policy based on natural uranium but continued to receive U.S. technical assistance. With American help and under strict U.S. regulations, Brazil built two nuclear reactors. According to Global Security, an online defense and policy information source, the National Nuclear Energy Commission (CNEN) was created formally on Aug. 27, 1962 as part of that independent nuclear policy.

According to Global Security, Brazil's military government, concerned with Argentina's rapid nuclear development, sought to develop its own nuclear technology independently but was frustrated by U.S. restrictions.

In 1975 Brazil signed an agreement with West Germany for the supply of technology for a complete nuclear fuel cycle, including enrichment and reprocessing. Following the deal, Brazil transferred the technology from its power plant projects to a secret program, code named Solimoes, to develop an atom bomb.

Luis Bitencourt, director of the Brazil Project at the Woodrow Wilson International Center for scholars, noted that during the 1980s Brazil's military government maintained ambiguity about the country's nuclear intentions, never acknowledging that a covert nuclear weapons program existed.

After taking office in 1990, President Fernando Collor de Mello took bold steps to control and restrict Brazil's nuclear program and to improve relations with Argentina. On May 30, 1994 Brazil ratified the Treaty of Tlatelolco, an agreement which calls for a nuclear-free zone in Latin America and the Caribbean, and in 1997 Brazil ratified the nuclear Non-Proliferation Treaty.

Recent developments by the Brazilian government have raised new concerns that Brazil may still be seeking the technological capability to produce a nuclear bomb. A 2004 article in Science magazine reported that Brazil is planning to commission a uranium enrichment plant at a new facility in Resende that, if configured to do so, could produce enough fuel for several nuclear weapons annually.

Brazil's science and technology minister Eduardo Campos has declared that "the Brazilian nuclear project is intended exclusively for peaceful purposes."

In early 2004, Brazil barred the IAEA from inspecting the Resende facility. After negotiations between Brazil and the atomic watchdog agency in late 2004, Brazil agreed to give IAEA inspectors access to the Resende facility, according to the Associated Press.

Brazil's uranium deposits, highly trained scientists and multiple nuclear research centers make it the most advanced nuclear nations in Latin America.

-- Compiled by Wendy Mbekelu for the Online NewsHour