United Nations officials declared Thursday for the first time that Tehran has amassed more than a ton of uranium – an amount which is sufficient, with added purification, to make an atom bomb. According to the New York Times, atomic inspectors found that Iran recently understated by a third how much uranium it has enriched.
In a report issued in Vienna, the International Atomic Energy Agency said it had discovered an additional 460 pounds of low-enriched uranium, a third more than Iran had previously disclosed. The agency made the find during its annual physical inventory of nuclear materials at Iran’s enrichment plant at Natanz.
According to the NYT report, “Independent nuclear weapons experts expressed surprise at the disclosure and criticized the atomic inspectors for making independent checks on Iran’s progress only once a year.”
“It’s worse than we thought,” Gary Milhollin, director of the Wisconsin Project on Nuclear Arms Control, told the newspaper. “It’s alarming that the actual production was underreported by a third.”
“You have enough atoms" to make a nuclear bomb, a senior United Nations official, speaking on the condition of anonymity because of the topic’s diplomatic sensitivity, told reporters on Thursday. His remarks confirmed estimates that private nuclear analysts made late last year. But the official noted that the material would have to undergo further enrichment if it was to be used as fuel for a bomb and that atomic inspectors had found no signs that Iran was making such preparations.
On Thursday evening, an Obama administration official who had reviewed the new report said, "There is a steady timeline of improvement, especially in terms of mastering the efficiency of the centrifuges," meaning that Iran has been able to increase its output of enriched uranium.
The official acknowledged that there were longstanding suspicions that Iran could have additional uranium enrichment sites that the inspectors had not seen or heard about. "Everyone’s nervous and worried about the possibility of Iran pursuing a clandestine capability," he said. The atomic agency’s quarterly report to its board, which was made public on Thursday, noted that Iran had now produced a total of 1,010 kilograms (2,227 pounds) of low-enriched uranium.
The officials dismissed suggestions that the discrepancy meant that Iran could smuggle enriched uranium out of the Natanz plant for processing at a secret location. “We’re sure that no material could have left the facility without us knowing,” the senior United Nations official said. But he admitted that the inspection teams do their own inventory just once a year. “It’s only at that moment,” he said, “that we have our own independent data.”
The report also gave updated figures for Iran’s use of centrifuges. At Natanz, it said, Iran is using about 4,000 centrifuges and has 1,600 more “in the wings,” for a total of 5,600. That compares with 3,800 working centrifuges listed in the agency’s November report.