More than a third of the increased output came from a formerly secret installation called Fordow, which began enriching uranium last month from inside a heavily fortified bunker carved into a mountain in northwestern Iran, the IAEA inspectors found.
Iran already has enough enriched uranium to build four nuclear weapons, if it decides in the future to do so. The shift to underground bunkers and a larger stockpile of the highly enriched uranium, however, could shorten the amount of time needed for Iran to develop a weapon, U.S. officials and nuclear experts say.
Iran would probably have to take additional steps, including kicking U.N. inspectors out of the country, before it is able to assemble a bomb.
Still, the jump in production was immediately criticized by U.S. and European officials who said Iran had undermined its credibility with a provocative spike in its production of nuclear fuel at at time when Iranian leaders were signaling an interest in restarting nuclear talks with the West. U.S. officials noted that Iran also sharply increased the number of centrifuges making enriched uranium at its main nuclear facility at Natanz.
“Iran’s actions demonstrate why Iran has failed to convince the international community that its nuclear program is peaceful,” White House spokesman Tommy Vietor said. Unless Iran changes course, “its isolation from the international community will only continue to grow,” Vietor said.
The report by the Vienna-based nuclear watchdog was the first since the breakdown last week of an extraordinary round of negotiations between the IAEA and Iranian nuclear officials. U.N. officials confirmed early reports that Iran had stonewalled the agency’s efforts to investigate allegations that Iran’s scientists had conducted extensive research on how to build a nuclear warhead.
“No agreement was reached between Iran and the agency,” the report said, adding that Iranian officials twice refused an IAEA request to visit a key research facility where some of the alleged experiments were said to have occurred.
Iran dismissed the IAEA’s concerns about alleged nuclear weapons research “largely on the grounds that Iran considered them to be based on unfounded allegations,” said the report, prepared in advance of a meeting next month of the Vienna agency’s 35-nation board of governors.
As a signatory to the international Nonproliferation Treaty, Iran is required to grant the IAEA access to its nuclear facilities to ensure that no nuclear material is being diverted to a nuclear weapons program. IAEA inspectors have unearthed no direct evidence that Iran is working on a building a bomb. But Iran’s growing stockpile of enriched uranium has fueled fears in the West that the country’s leaders are at least seeking the option to develop nuclear weapons in the future. Iranian officials say the country’s nuclear program is intended only for electricity production.
Most worrisome to U.S. officials is Iran’s shift to a purer form of enriched uranium. Most of the country’s stockpile consists of the 5 percent enriched uranium used in nuclear power plants. But the IAEA’s new report documented a sharp rise in the production of a 20 percent enriched uranium.
Iran claims that it will use the material to make fuel rods for the country’s sole medical research reactor, but its stockpile of 20 percent uranium already far surpasses the country’s projected needs, nuclear experts say. U.S. officials note that 20 percent enriched uranium can be quickly converted to weapons-grade uranium using equipment Iran already has.
The surplus grew further since the fall, the IAEA report said, as Iran added more than 78 pounds of the purer form of enriched uranium to the 163 pounds it already had, the agency said. The rate of production of the fuel tripled over the past four months, according to an analysis by the Institute for Science and International Security, a Washington nonprofit group that researches nuclear weapons programs.
Some nuclear experts say they suspect the new stockpiling may be an attempt by Iran to improve its bargaining position ahead of any new nuclear talks with the West.
Jeffrey Lewis, a nuclear weapons expert at the James Martin Center for Nonproliferation Studies, said it was probably significant that Iran began its production of 20 percent enrichment at the underground Fordow plant before Iranian officials formally proposed a new round of nuclear talks with the so-called P5-plus-1 nations — the United States, Russia, China, Britain, France and Germany.
“Iran is steadily creating facts in the ground, such as enrichment to 20 percent at the underground site near Qom,” Lewis said. Whatever the motivation, Iran has succeeded in “pushing this standoff toward a military confrontation that leaves Iran isolated but with the bomb.”
In a rare bright spot for Western countries, the report showed Iran continuing to struggle to perfect more advanced centrifuges that could vastly increase its rate of uranium enrichment.
“Tension and risk is moderated by the failure, or severe trouble, of Iran’s other main nuclear plank — advanced generation machines,” said Cliff Kupchan, a former State Department official and director of Middle East analysis for the Euraisa Group, a private consulting firm. “On balance, the report will keep tensions at a high level, but it does not change the trajectory of the crisis.”