In their first appraisal of Iran’s nuclear program since President Obama took office, atomic inspectors have found that Iran recently understated by a third how much uranium it has enriched, UN officials said Thursday.
The officials also declared for the first time that the amount of uranium that Tehran had amassed — more than a ton — was sufficient, with added purification, to make an atom bomb.
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 desert enrichment plant at Natanz.
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, said in an interview. “It’s alarming that the actual production was underreported by a third.”
The political impact of the report, while hard to measure, could be significant for the Obama administration. Obama has said that he wants to open direct talks with Iran about its nuclear program. But that process could take months, and the report suggests that Iran is moving ahead briskly with its uranium enrichment.
“You have enough atoms” to make a nuclear bomb, a senior U.N. 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 term 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 long-standing 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 disclosure of the unaccounted third came in the atomic agency’s quarterly report to its board, which was made public on Thursday. The report noted that Iran had produced a total of 1,010 kilograms — or 2,227 pounds — of low-enriched uranium.
The discrepancy came to light when the report noted that the new total came from the addition of 171 kilograms of new production to 839 kilograms of old production. But the agency had previously reported the old production as 630 kilograms.