Early Sunday, if all goes as planned, U.N. nuclear inspectors will travel to a military base near Qom, Iran, for a first look at one of the country's most closely guarded nuclear secrets. Inside bunkers dug into the side of a mountain, the visitors will be escorted through a nearly completed uranium plant that Iran's president has termed "very ordinary."
But less than a month after its existence was publicly revealed, many U.S. and European intelligence officials say they are increasingly convinced that the site was intended explicitly for making highly enriched uranium for nuclear weapons.
The Qom site has undermined one of the U.S. intelligence community's key assessments of Iran's nuclear program: the assumption that Tehran had abandoned plans to enrich uranium in secret, according to two former senior U.S. officials involved in high-level discussions about Iran.
A landmark U.S. intelligence assessment in 2007 concluded that any secret uranium-processing activities "probably were halted" in 2003 and had not been restarted. Other key judgments of the 2007 National Intelligence Estimate, including the view that Iran has suspended research on nuclear-warhead design, are also being reevaluated in light of new evidence, the two former officials said.
"Qom changed a lot of people's thinking, especially about the possibility of secret military enrichment" of uranium, said one of the former officials, who spoke on the condition of anonymity because the assessments remain classified.
In interviews, intelligence officials from the United States and allied nations said their scrutiny of the Qom site was longer and deeper than previously acknowledged, and included acquiring detailed plans on how the facility would be outfitted and operated.
Intercepted communications revealed a key piece of data: Iranian plans to place only 3,000 centrifuge machines in the plant. That number is too small to furnish fuel for a civilian power plant, but just big enough to supply Iran annually with up to three bombs' worth of weapons-grade fuel, the former officials said.
Insights into the spy community's evolving views about Qom were provided by current and former intelligence and government officials in interviews in the United States, Central Europe and several Middle Eastern countries. In nearly all cases, the officials spoke on the condition that their names and nationalities not be revealed, citing the secrecy of the ongoing assessments of Iran's nuclear program.
No ‘smoking-gun’ evidence
The officials acknowledged that the Qom complex is not yet operational and that no uranium had been enriched at the time the site was revealed last month. They also acknowledged there is no "smoking-gun" evidence that Iran plans to make bomb-grade uranium. But the officials said the Qom site was structurally suited for that purpose, and they concluded that there is no plausible role for the plant in Iran's civilian nuclear power infrastructure.
Iran officially notified the Vienna-based International Atomic Energy Agency about the existence of the Qom site in a letter on Sept. 21. U.S. and European officials say Iranian officials learned that the United States was aware of the site and rushed to disclose the facility's existence to head off accusations that it was running a covert nuclear program.
Iranian President Mahmoud Ahmadinejad has said the Qom site is part of Iran's legitimate, civilian nuclear power program, contending that he planned all along to disclose the facility to the U.N. nuclear watchdog and to allow international oversight.
Ali Akbar Salehi, who heads Iran's civilian Atomic Energy Organization, said the facility was built underground at a military installation to shield it from foreign attack, and also to save money. The intention was "to safeguard our nuclear facilities and reduce the cost of an active defense system," Salehi told reporters in Tehran.
Chipping away at a secret
For at least the past five years, the complex at Qom has been both a closely guarded secret and one of the heavily scrutinized pieces of real estate on Earth.
It is, in some ways, a perfect spot for a hidden nuclear facility. The nearby city of Qom has been known since medieval times as a Shiite religious center; it contains notable religious schools and shrines but no known nuclear facilities. The country's other uranium-enrichment plant, near Natanz, is 60 miles away. Two military bases for medium-range Shahab missiles and antiaircraft batteries lie just beyond the outskirts, and one of these, in a mountainous area about 10 miles north of town, is pocked with tunnels and bunkers used for storing rockets.
Exactly when the order was issued to build the Qom facility is unclear, but intelligence officials say they have studied the site at least since 2004.
An exiled opposition group, the National Council of Resistance of Iran, first publicly revealed the existence of Iran's much larger uranium facility at Natanz in 2002. It highlighted Qom's tunnels at a December 2005 news conference and later supplied details to U.N. officials, according to a spokesman for the group. Iran said the site was a closed military property, and no nuclear inspections were permitted.
But from the air and ground, Western satellites and spies scoured its every portal and ventilator shaft, collecting terabytes of data about the facility, including communications intercepts. The CIA teamed up with intelligence operatives from U.S.-allied countries for sophisticated eavesdropping operations, officials confirmed. By last year, a series of breakthroughs confirmed that the Iran was building a secret uranium-enrichment plant, and also yielded precise details about how it would be operated, including the number of centrifuges Iran planned to use and how much electricity the facility would consume.
A retired senior U.S. intelligence official who followed the case closely said the evidence was unusually good, with many "verified sources" providing data "beyond the visible light spectrum," or beyond satellite images and spy-plane photos. "It was truly a multi-discipline effort, and it went on for a long period of time," the retired official said. "The more we learned, the more confident we became."
CIA Director Leon Panetta, in response to questions from The Washington Post, said in a statement that the agency was able over time to "draw a clear picture of Iran's activities and intentions at this site."
Iran has revealed that it planned to use a more sophisticated centrifuge machine at Qom -- one that can produce enriched uranium at twice the rate as the older-model machines it uses at the Natanz plant. Even so, the amount of uranium eked out annually by Qom's 3,000 centrifuges would be far short of the quantity needed to fuel a commercial nuclear reactor.
Intelligence analysts calculated that it would take Qom's high-end centrifuges at least 20 years to produce enough low-enriched uranium to meet the needs of a typical 1,000 megawatt nuclear power reactor for a year.
If configured for weapons, however, Qom could produce enough bomb-grade fuel for two to three bombs annually, intelligence officials said.
"There is no Iranian document saying the facility is designed for a military program, but what else can it be good for?" said a senior Middle East-based intelligence official involved in Iran analysis.
The official, and other intelligence officers interviewed, said they rejected the possibility that the Qom site was intended as a pilot plant or testing facility for new types of centrifuges. Iran already has two such facilities, at Natanz and in Tehran, and neither runs at anything close to capacity, they said.
Intelligence officials say it is unlikely that Iran will try to manufacture weapons-grade uranium at Qom, now that the site has been revealed . But Western spy agencies say they do not know where Qom's supply of uranium feedstock -- uranium hexafluoride, or UF6 -- was supposed to come from. If Iran were to try to divert UF6 from its existing stockpile to a secret facility, U.N. inspectors would almost certainly detect the change.
"Is there another secret facility somewhere? said the senior Middle East-based intelligence officer. "I'd now have to say yes, almost certainly."
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