Iran's Uranium Glitch

By David Ignatius
Friday, September 29, 2006

Intelligence analysts believe that Iran is encountering technical difficulties in mastering the complex process of uranium enrichment. That means the West may have a bit more time than previously expected to pursue a diplomatic solution to the Iranian nuclear standoff.

The problem, according to intelligence officials, is that the centrifuges that are supposed to enrich uranium are overheating. Some are breaking down and must be replaced. As a result, Iran has not ramped up its enrichment effort as quickly as analysts had expected.

This assessment is based on recent conversations with analysts from several Western nations that are watching the Iranian program closely and on an unpublished report by the International Atomic Energy Agency that was completed Aug. 31. To me, it's the equivalent of adding some extra time to the clock in a tense football game. The urgency remains, but there is an opportunity for a few additional plays before the game is over.

"There's time, purely from the point of view of the technical development of the threat, to let diplomacy play out in the case of Iran," says Harvard professor Ashton B. Carter, who closely follows the issue.

The technical difficulties involve the uranium enrichment facility in Natanz, north of Isfahan in central Iran. The Iranians broke IAEA seals at Natanz in January and began enriching uranium. It's a highly complex process, in which uranium gas is injected into the linked array of centrifuges that spin at roughly the speed of sound. President Mahmoud Ahmadinejad announced April 11 that the Iranians had succeeded in enriching uranium to an initial level of 3.5 percent, and in June Iran told the IAEA it had achieved 5 percent enrichment. That's far below the 90 percent level needed for a nuclear weapon, but it suggested the Iranians were on their way to mastering the technology.

Western analysts had expected that the Iranians would move quickly to expand the enrichment effort to meet their near-term goal of having six cascades of 164 centrifuges each, or a total of nearly 1,000 centrifuges. The danger here was technological mastery rather than raw output of uranium. Even with 3,000 centrifuges operating, intelligence analysts estimate that it would take two to three years to produce enough highly enriched uranium for one bomb. Iran's eventual goal is a massive array of more than 50,000 centrifuges at Natanz.

But problems surfaced this summer. The Aug. 31 IAEA report, marked "Restricted Distribution," noted that since June, Iran had been feeding uranium into a small 20-centrifuge test cascade "for short periods of time," and that it had conducted various tests in June, July and August of the initial 164-centrifuge cascade. "The installation of a second 164-machine cascade is proceeding," the report noted, but it added that Iran planned to test the second cascade in September without injecting uranium.

What happened to slow the expected pace? IAEA analysts have told U.S. and European officials that it appears the centrifuges are overheating when uranium gas is injected. "The Iranians are unable to control higher temperatures, and after a short period they must stop because of higher temperatures. So far they haven't been able to solve this," says one Western intelligence official who has been briefed on the IAEA findings. In addition, this official said, some centrifuges "are simply crashing -- 10 or so have broken down and must be replaced."

There's a lively debate among intelligence analysts about what may be causing these problems. One theory holds that Iran's home-produced uranium, mixed with foreign ore, isn't sufficiently pure for the delicate centrifuges, but other analysts reject that argument. Several analysts I talked to agreed, however, that if Iranian scientists continue with enrichment, they are likely to solve the technical problems eventually through trial and error. That's why U.S. and European officials are still calling for Iran to suspend enrichment, before they have cracked the puzzles they are encountering.

Iran continues to insist that its nuclear program is peaceful. And although it's taken for granted in many Western countries that these statements mask a secret plan to build nuclear weapons, intelligence analysts from several nations told me they lack decisive evidence of an Iranian bomb effort. So far, there is no "smoking gun," said an intelligence analyst from one Western nation. Nevertheless, the United States, Israel and some European countries remain convinced that a covert weapons program exists.

The clock is still ticking. That's the real import of these new intelligence findings. Iran and the West still have time to find a diplomatic solution to the nuclear showdown. This genie isn't quite out of the bottle.

The writer co-hosts, with Newsweek's Fareed Zakaria, PostGlobal, an online discussion of international issues at His e-mail address

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