The International Atomic Energy Agency (IAEA) sought access to the facility in Resende, in the state of Rio de Janeiro, ElBaradei told a local newspaper.
ElBaradei told O Globo daily that Brazil should not be an exception to IAEA norms. He granted the interview in Moscow.
ElBaradei said the IAEA needed to see the equipment itself because it was the only way to assure that no uranium was being enriched beyond that which had been declared.
Brazilian authorities offered to allow IAEA to weigh uranium leaving the facility.
ElBaradei discounted Brazil's claim to trade secrets, saying that whatever kind of centrifuges Brazil uses in the process, there is not a large market in which to sell them.