In the 1970s and 1980s, during the military regime, Brazil had a secret program intended to develop nuclear weapons. The program was dismantled in 1990, five years after the military regime ended, and Brazil is considered free of weapons of mass destruction. Brazil is one of many countries (and one of the last) to forswear nuclear weapons under the terms of the Non-Proliferation Treaty but possesses some of the key technologies needed to produce nuclear weapons. Nuclear program In the 1950s, President Getúlio Vargas encouraged the development of independent national nuclear capabilities. At that time, the United States worked actively to prevent Brazil from acquiring the centrifuge technology that could be used to produce high-enriched uranium for nuclear weapons. During the 1970s and 80s, Brazil and Argentina embarked on a nuclear competition. Through technology transfers from the West German company, Kraftwerk Union (a subsidiary of Siemens), which did not require IAEA safeguards, Brazil pursued a covert nuclear weapons program known as the "Parallel Program", with enrichment facilities (including small scale centrifuge enrichment plants, a limited reprocessing capability, and a missile program). Brazil also reportedly bought highly enriched uranium from China in the 1980s. In December 1982, then-president of the National Nuclear Energy Commission (CNEN), Rex Nazaré, headed a mission to China with the objective of purchasing enriched uranium from his Chinese counterparts at the China National Nuclear Corporation. Sources have indicated that, a few years later, Brazilian cylinders of hexafluoride were transported to China containing natural uranium. They returned to Brazil in a container that, supposedly, carried porcelain purchased by the First Lady Dulce Figueiredo during the presidential trip. In 1987, President Sarney announced that Brazil had enriched uranium to 20%. In 1990, President Fernando Collor de Mello symbolically closed the Cachimbo test site, in Pará, and exposed the military’s secret plan to develop a nuclear weapon. Brazil's National Congress opened an investigation into the Parallel Program. Congress members visited numerous facilities, including the Institute of Advanced Studies (IEAv) in São José dos Campos. They also interviewed key players in the nuclear program, such as former President João Figueiredo and retired Army General Danilo Venturini, the former head of the National Security Council under Figueiredo. The congressional investigation exposed secret bank accounts, code-named "Delta", which were managed by the CNEN and used for funding the program. The congressional report revealed that the IEAv had designed two atomic bomb devices, one