Iran has plans to install tens of thousands of advanced centrifuges at its huge underground nuclear plant near the central city of Natanz, which eventually would enable the nation to enrich uranium nearly twice as fast as anticipated, Western intelligence officials say.
The officials say there is no hard evidence that Iran is currently manufacturing the updated centrifuges and that the timetable for installation remains unknown. However, preparatory work is underway at the plant, they said in recent interviews, and the decision to rely on the superior type of centrifuge suggests Iran could manufacture fissile material for a possible weapon sooner than expected.
Diplomats with knowledge of Iran’s nuclear program said they could not confirm the information, but Tehran said last year that it intended to use the advanced centrifuges at some point.
Iran insists that its nuclear program is for peaceful purposes, but the United States and European Union fear that the country intends to build atomic weapons, in violation of the Nuclear Nonproliferation Treaty.
Stopping Iran from mastering the process of uranium enrichment is the central goal of the U.S. and EU. They have threatened to turn to the U.N. Security Council if Tehran abandons an agreement, reached with three European governments in November, to suspend enrichment activities.
The concern is that Iran, after developing sufficient enrichment capabilities, could more readily shift production from low-level enriched uranium for nuclear reactors to high levels for weapons, either secretly or after withdrawing from the nonproliferation treaty.
On Sunday, Iranian officials pledged to extend the country’s voluntary suspension of enrichment activities until the end of July as part of the nuclear negotiations with Germany, France and Britain. But Tehran has called the suspension voluntary and temporary and says it intends to eventually produce fuel for civilian reactors.
An inspection team from the International Atomic Energy Agency, the U.N.'s nuclear watchdog, will begin work today in Natanz. The team will verify whether Iran is complying with the enrichment suspension ahead of an IAEA board meeting next week in Vienna.
The complex at Natanz, about 150 miles south of Tehran, is the heart of Iran’s enrichment effort. Plans call for more than 50,000 centrifuges to be installed in two vast underground halls, where they could produce large quantities of enriched uranium, the Western intelligence officials said.
Earlier this year, Iran finished covering the main plant with 25 feet of concrete and an additional layer of earth. Satellite photos show that the entrance to the underground complex and two large air shafts were concealed by what appear to be dummy buildings.
Journalists taken on a government-led tour of Natanz in March reported that the 1,100-acre site was ringed by at least 10 antiaircraft batteries. Iranian officials said the missiles and underground facilities were prompted by concerns over possible attacks by the U.S. or Israel.
The IAEA has been investigating Iran’s nuclear program since an exile group disclosed the existence of Natanz in August 2002, exposing an ambitious Iranian effort that had been kept secret for nearly two decades.
Though questions remain, the IAEA says it has found no evidence of a weapons program.
Two Western intelligence officials and a nuclear expert, all from a government opposed to Iran’s nuclear efforts, said they had developed “very solid information” about plans to manufacture and install 54,000 centrifuges at Natanz. They said up to two-thirds of them would be the advanced model, known as the P-2.
They said they were uncertain about the key issue of when Iran would build and install the machines.
Tehran told the IAEA last year that it had stopped all research and development on P-2s. If Iran is building the advanced centrifuges, that would violate its agreements with the three European nations and the international agency, diplomats said.
In separate interviews, diplomats close to the IAEA said that, although it is likely Natanz will eventually house P-2s, they had no information that Iran was working on the machines.
“Their having made some planning should not be overly surprising,” a Western diplomat in Vienna said. “However, if there were production going on, it would be a breach of the suspension.”
A senior Iranian official dismissed the idea that Iran was now working on P-2s, but he said Natanz was designed to accommodate either the P-2 or the less advanced P-1.
A senior IAEA official is expected to provide an update on Iran’s compliance when the board meets next week. The Western diplomat in Vienna suggested that the release of information about the P-2s was timed to fuel doubts about Iran.
“The question has been: Do they already have the P-2 developed and demonstrated?” said David Albright, a former IAEA inspector who is head of the Institute for Science and International Security in Washington. “My understanding is that there is not much progress being made on this [question] by the IAEA.”
Russia has agreed to provide fuel for Iran’s nuclear reactor at Bushehr, which is to begin operating next year, but Tehran says it plans a series of reactors to generate electricity and wants to produce its own fuel.
Iran began building P-1 centrifuges several years ago and told the Europeans in April that it would install 3,000 of them at Natanz.
That number is far more than planned for a nearby pilot plant and could turn out enough enriched uranium for one or two bombs in a year, Albright said.
The Bush administration recently pushed back its estimate of the date by which it believes Iran could produce an atomic weapon if it resumed enrichment activities.
Vice Adm. Lowell E. Jacoby, director of the Pentagon’s Defense Intelligence Agency, told a Senate committee in March that Iran was not expected to be able to produce a weapon before early in the next decade, several years later than earlier estimates. Albright said he was told that assessment was shared throughout the U.S. intelligence community.
However, Israeli intelligence estimates that Iran could have a nuclear weapon within two years or less of resuming enrichment.
Iran admitted under pressure last year that it had secretly bought parts and designs for the P-1 centrifuge from Pakistani scientist Abdul Qadeer Khan in the late 1980s. Iranian officials later acknowledged that the Khan network sold them designs for the more efficient P-2 in 1995.
Iranian officials told the IAEA that they did not work on the P-2 until 2002 and that those efforts were unsuccessful and were halted in 2003.
In a report issued last November, the IAEA said a private contractor in Tehran hired by the government had acknowledged trying to buy 4,000 magnets suitable for P-2 centrifuges from a European company and had suggested that he might want far more. Iran also said it had bought magnets suitable for P-2s in 2002.
The IAEA said it did not have enough evidence yet to determine whether Iran was telling the truth about the absence of work on the P-2 for seven years. A second diplomat in Vienna said the work had not resumed.
It is unclear how quickly Iran could turn out the required number of P-2s. Centrifuges are complex, finely balanced machines, with about 100 parts manufactured to precise tolerances.
P-2s are designed to use rotors manufactured from specialized steel, which Iran would probably have to acquire abroad. Iranian attempts to substitute a carbon-fiber compound in 2002 and 2003 ran into difficulties, the IAEA says.