TEHRAN — Iran has enough nuclear fuel to build a bomb if it decides to take the drastic steps of violating its international treaty obligations, kicking out inspectors and further refining its supply, U.N. officials and arms control experts said Thursday.
Iran has made no such gestures and has slowed its expansion of machinery producing nuclear fuel, having increased production capacity by less than 5% over the last three months, according to a report issued Thursday by the International Atomic Energy Agency.
Another IAEA report released Thursday raises suspicions about graphite and uranium particles found at an alleged nuclear site in Syria that was bombed by Israel in 2007.
The reports, the latest updates from the arms control watchdog for the United Nations, show that Iran had amassed about 2,227 pounds of low-enriched, or reactor-grade, nuclear fuel by late January. Physicists estimate that producing the 55 pounds or so of highly enriched, or weapons-grade, uranium needed for an atomic warhead requires 2,205 to 3,748 pounds of low-enriched uranium.
Iran's increased supply of low-enriched uranium surprised diplomats and arms control experts who had assumed that Iran would need until the end of the year to acquire enough fuel for a bomb.
One expert, David Albright of the Washington-based Institute for Science and International Security, said he was "blindsided" by the report.
"We are surprised," Albright said. "We did not expect this."
Senior officials close to the Vienna-based IAEA told reporters and arms control experts in a conference call Thursday evening that Iranian officials said they had "miscalculated" their stockpile of low-enriched uranium, an error that was cleared up with agency officials in mid-November but never made public.
Iran steadfastly denies that it hopes to build an atomic bomb, which the country's supreme leader, Ayatollah Ali Khamenei, says violates the principles of Islam. It says its nuclear program is intended solely to produce energy for Iran's growing population.
But the United States, Europe and Israel suspect Iran is trying to attain a nuclear weapons capacity that could have strategic implications for the Middle East.
By crossing the 2,205-pound threshold, experts say, Iran has improved its "breakout" capacity, the ability to renege on treaty obligations, kick out inspectors and quickly build a bomb.
