Enrichment capacity and stockpiles are up at key plant.
WASHINGTON - Iran has installed three-quarters of the nuclear centrifuges it needs to complete a site deep underground for the production of nuclear fuel, international inspectors reported Thursday, a finding that led the White House to warn that "the window that is open now to resolve this diplomatically will not remain open indefinitely."
The report by the International Atomic Energy Agency (IAEA), the last to be issued before the U.S. presidential election, lays out in detail how Iran over the summer has doubled the number of centrifuges installed deep under a mountain near the holy city of Qom. Iran has also cleansed another site where the agency has said it suspects that the country has conducted explosive experiments that could be relevant to the production of a nuclear weapon, the report said.
Based on satellite photographs, the agency said, the cleanup had been so extensive that it would "significantly hamper" the ability of inspectors to understand what kind of work had taken place there.
The report confirmed that a recent boast by Iran's supreme leader, Ayatollah Ali Khamenei, that the country had added nearly 1,000 centrifuges to the underground site was accurate.
Motives are unclear
But it left open the question of what, exactly, Khamenei and other Iranian leaders intend to do with those machines, and whether, by racing ahead with construction, they were seeking negotiating advantage or trying to gain the ability to build a bomb before sanctions, sabotage or military action could stop them.
The report offers arguments for both sides in the debate over whether a military strike on Iran's nuclear sites is necessary to prevent Iran from producing a nuclear weapon.
The Israelis in favor of military action, led by Defense Minister Ehud Barak, the most outspoken proponent of moving quickly against the Iranian program, will point to evidence that Iran has now installed more than 2,100 of the roughly 2,800 centrifuges destined for the underground site, called Fordo. More than 1,000 have been installed in the past three months, since the last report by the agency.
For Barak, that is evidence that the "zone of immunity" he has warned about -- the point at which Iran will be able to produce nuclear fuel from a site invulnerable to attack -- will be reached in a matter of weeks.
But U.S. officials urging caution will find plenty in the report to bolster their view as well. Only a third of the centrifuges at Fordo are operating, the inspectors reported, leaving open the question of whether Iran had run into technical difficulties or had made a political decision not to tempt its adversaries by rushing ahead in moving production of fuel to its best-protected facility.
The centrifuges being installed at Fordo, U.S. officials noted, are of the old and unreliable model that Iran obtained from Pakistan, and they do not include any newer, more efficient models that the Iranians have claimed for years that they would move to.
And while the agency's statistics show that Iran has, since February, nearly doubled its stockpile of fuel enriched to 20 percent purity -- a level that experts say could be converted to bomb grade in months -- it still does not possess enough of that fuel to produce a complete nuclear weapon.
Some of the 20 percent fuel is in a form that is extremely difficult to use in a bomb, and most of the stockpile is made up of a fuel enriched at a lower level that would take considerably longer to process for weapons use.
'Very strategic about it'
Iran has declared, publicly and to the agency, that it is producing its fuel enriched at 20 percent solely for a reactor that is used to produce medical isotopes for cancer treatments. A European diplomat pointed out Thursday that Iran now had enough of the fuel to keep that reactor running for many years, although the country has declared that it will continue producing the fuel at a faster pace.
Iran has continued to allow inspectors inside the Fordo plant to verify that it is not producing bomb-grade material.
"They have been very strategic about it," one senior U.S. official said. "They are creating a tremendous production capability, but they are not yet using it. That gives them leverage, but they think it also stops short of creating the pretext for an attack."