Despite Iran claimed to had activated 3,000 of the devices it is only operating several hundred centrifuges at its uranium enrichment plant at Natanz, the head of the U.N. nuclear watchdog agency said Thursday.
Iranian President Mahmoud Ahmadinejad announced earlier this week that the Natanz facility had begun "industrial-scale" production of nuclear fuel in a major advance in Iran's uranium enrichment program, which the United Nations has demanded be halted.
Iran's top nuclear negotiator said Sunday that workers had begun injected uranium gas into a new array of 3,000 centrifuges, a large jump over the 328 centrifuges known to be operating at Natanz. Iran ultimately aims to operate more than 50,000 of the devices at the site.
But Mohammed ElBaradei, head of the U.N.'s International Atomic Energy Agency, played down the extent of Iran's progress at Natanz.
"Iran is still just at the beginning stages in setting up its Natanz enrichment facility. The talk of building a facility with 50,000 centrifuges is just at the beginning, and it is (currently) only in the hundreds," ElBaradei told reporters in the Saudi capital, Riyadh.
Two IAEA inspectors are currently in Iran and are due to visit Natanz in the coming days. It was not clear what information ElBaradei was basing his comments on.
Iran's claims of major progress at Natanz, made Sunday, were met by skepticism from international officials and experts, who pointed out that Iran has had difficulty keeping its smaller arrays of 328 centrifuges operating constantly.
But the announcement was a strong show of defiance to the United Nations, which has imposed sanctions on Iran for its refusal to suspend enrichment and has warned of more to come.
In the enrichment process, uranium gas is injected into cascades of thousands of centrifuges, which spin and purify it. If enriched to a low level, the result is fuel for a nuclear reactor. To a much higher level it can build the material for a nuclear warhead.
The United States and its allies accuse Iran of seeking to develop nuclear weapons, a charge Tehran denies.