IAEA: Iran Enriching Uranium Gas

Iran has started enriching small amounts of uranium gas at its underground plant and is already running more than 1,300 of the machines used in the enrichment process, according to an International Atomic Energy Agency document obtained Wednesday by The Associated Press.

The confidential document — a letter to Iranian officials from a senior IAEA staff member — also protests an Iranian decision to prevent agency inspectors to visit the country's heavy water facility that, when built, will produce plutonium. Enriched uranium and plutonium can both be used for the fissile core of nuclear warheads.

Last week, Iran said it had begun operating 3,000 centrifuges at its Natanz facility, nearly 10 times the previously known number. The United States, Britain, France and others criticized the announcement, but experts, and several world powers, expressed skepticism that Iran's claims were true and diplomats in Vienna familiar with the state of the program told the AP they were greatly exaggerated.

Still, the one-page letter reflected a swift advance in the program. A little more than two weeks ago, those diplomats had said Tehran was running only a little more than 600 centrifuges, and had not introduced any uranium gas into them.

The letter, signed by IAEA Deputy Director General Olli Heinonen and dated April 18 said the agency wanted to "take note of the information provided by Iran ... that Iran has put into operation" 1,312 centrifuges, the machines used to spin the gas into enriched uranium.

The letter also cited Iranian information to the agency that "some UF6 is being fed" into the centrifuges, referring to the uranium gas that can be enriched to levels potent enough to be used for nuclear arms.

Iran says it wants to enrich only to lower levels suitable to generate nuclear power. But suspicions about its ultimate intentions, after nearly two decades of nuclear secrecy exposed only four years ago, have led to U.N. Security Council sanctions for its refusal to freeze its enrichment program.

"Regardless of whether the timetable is one year or five, Iran is proceeding to enrich uranium to industrial grade in defiance of U.N. sanctions," said CBS News foreign affairs analyst Pamela Falk, "buying time with each six-month period that the Security Council sanctions allow."

"There is a sense at the U.N., among the permanent members of the Security Council, that something else needs to be done alongside the sanctions to convince Iran to get back to compliance," adds Falk.

It was unclear what the purpose of the uranium gas feed was. A diplomat accredited to the IAEA, who demanded anonymity because he was disclosing confidential information, said the operation appeared to be part of "stress tests" meant see if the machines were running smoothly.

But he and another diplomat said that, even if the operation was not meant to enrich large amounts of uranium, it appeared to be the last step before larger-scale enrichment begins.

Tehran's heavy water enrichment facilities at Arak also are under suspicion, because the plant, once constructed, will produce plutonium, which can also be used in an arms program. Iran argues it needs the plant for medical research, despite a Security Council demand that it also freeze construction at Arak.

When it is completed within the next decade, Arak will produce enough plutonium for two bombs a year.

Iran last month announced it was unilaterally abrogating part of its Safeguards Agreements linked with the IAEA under which Tehran is obligated to report to the agency six months before it introduces nuclear material of any kind into any facility. In his letter, Heinonen suggested that Iran invoked this move in denying his inspectors the right to visit the Arak facility, but argued it was illegal, because such agreements "cannot be modified unilaterally."

Beyond that, Heinonen said, IAEA inspectors should be allowed to visit Arak because the section abrogated by Iran had to do with early provision of design information of new nuclear facilities and "not to the frequency or timing of" agency inspections to verify information on design already provided by Iran.

Ali Ashgar Soltanieh, the chief Iranian delegate to the IAEA, did not specifically answer those concerns but asserted at a public lecture at the University of Vienna that his country had "no obligation to inform the IAEA" beyond the point that it was prepared to do so.

He said Iran cannot except Security Council demands that it suspend enrichment because they represent a "humiliation of the nation." But he said the Islamic republic was ready to negotiate on international concerns about its nuclear ambitions as long as the precondition of an enrichment freeze was dropped.