The Washington Post newspaper reported over the weekend that the International Atomic Energy Agency and Brazil were at an impasse over inspections of the uranium processing plant in Resende, near Rio de Janeiro.
Brazil, which denies it has imposed any restrictions on inspectors, maintains the plant will produce low-enriched uranium for use in power plants, not the highly enriched material used in nuclear weapons.
"There are no conceptual secrets," said scientist Luis Pinguelli Rosa, currently president of Brazil's national electricity concern, Electrobras.
"But there are advanced technological solutions that Brazil has the right to guard," he said.
Those "technological solutions" include equipment setup and materials used, he added.
Pinguelli insisted that Brazi's program was peaceful, and that Brazil uses an ultracentrifugation process used in Europe, while the United States and Russia use the different gas diffusion process.
"There is in no way a need for a further 'intrusion' (of the inspectors) to check the uranium enrichment," Pinguelli said.
It comes down to a "matter of principles" for Brazil to stand up to the "imperial position" of the United States, he added.
Brazil is a member of the nuclear Non-Proliferation Treaty, as well as the Tlateloco treaty which bans nuclear weapons in Latin America.
Also, the Brazilian Constitution clearly prohibited atomic weapons, he said.