Iran is expanding its uranium enrichment program despite the growing threat of UN Security Council sanctions for defying a council demand that Tehran give up the activity and ease fears that it seeks to make nuclear arms, diplomats said on Monday.
The diplomats, who spoke on condition of anonymity as they were not authorized to divulge the information to media, said that within the past few weeks Iranian nuclear experts had started up a second pilot enrichment facility.
While the 164 centrifuges were not producing enriched uranium, even the decision to "dry test" them showed Iran's defiance of the Security Council.
The council had set an Aug. 31 deadline for Tehran to cease all experiments linked to enrichment, which can produce the fissile material for nuclear warheads. It may start full deliberations on sanctions as early as later this week.
Iran produced a small batch of low-enriched uranium -- suitable as nuclear fuel but not weapons grade -- in February, using its initial cascade of 164 centrifuges at its pilot plant at Natanz. The process of uranium enrichment can be used to generate electricity or to create an atomic weapon, depending on the level of enrichment.
Iran has said it plans to install 3,000 centrifuges at its enrichment plant in Natanz, in central Iran, by the last quarter of this year. Industrial production of enriched uranium in Natanz would require 54,000 centrifuges.
Although it is nowhere near that goal, successful testing of other "cascades" would indicate that Tehran is slowly mastering the complexities of producing enriched uranium.
A UN official said that even a "dry-run" allows Tehran "to develop the technology, to make sure that things work."
Another UN official with close knowledge of Tehran's nuclear activities said Iran had the technical means to start the second cascade several months ago, but apparently had decided to wait until the recent collapse of EU attempts to revive negotiations on an enrichment freeze with the Islamic republic.
There was no official confirmation from the International Atomic Energy Agency (IAEA), which has taken the lead in probing Tehran's nuclear apparatus since the existence of a clandestine enrichment program was revealed more than three years ago.
Ali Ashgar Soltanieh, the chief Iranian envoy to the IAEA, said he had no knowledge of "new developments" at Natanz, adding that all nuclear activities "are going on as planned."
In Tehran, President Mahmoud Ahmadinejad suggested his country remained firmly committed to enrichment, boasting that his country's nuclear capability had increased "10-fold" despite international pressure to roll back its efforts.
"The enemies, resorting to propaganda, want to block us from achieving [nuclear technology]," Ahmadinejad told a crowd on the southern outskirts of Tehran.
"But they should know that today, the capability of our nation has multiplied 10-fold over the same period last year," he added.
In remarks that appeared aimed primarily at rallying public support amid the Security Council preparations, Ahmadinejad boasted that "the power of our enemies is less than one-tenth of their power in last year."
Iran's top nuclear negotiator, Ali Larijani, warned, meanwhile, that sanctions could backfire by making Tehran "more determined to continue with its nuclear activities," the country's official news agency reported.