Iran has installed many more uranium enrichment machines in an underground bunker, diplomatic sources said on Thursday, potentially paving the way for a significant expansion of work the West fears is ultimately aimed at making nuclear bombs.
Several sources said Iran had put in place additional enrichment centrifuges in its Fordow facility, buried deep inside a mountain to protect it against any enemy strikes. One source suggested it involved hundreds of machines.
"Our basic understanding is that they were continuing to install," a Vienna-based diplomat said, adding the new centrifuges were not yet operating.
If confirmed in a report expected next week from the UN atomic watchdog, the development is likely to be seen as a sign of Iran's continued defiance of international demands to curb its nuclear program, which Tehran says is entirely peaceful.
At Fordow, near the holy Shi'ite Muslim city of Qom, Iran is enriching uranium to a fissile concentration of 20 percent, activity which the West wants it to stop immediately as it brings it closer to the level required for nuclear weapons.
Iran denies Western allegations that it is seeking a nuclear weapons capability, saying it needs to refine uranium to that level to provide fuel for a medical research reactor.
But its refusal to suspend enrichment - which can have both civilian and military uses - has been met with increasingly tough Western sanctions and heightened speculation that Israel may attack its nuclear sites.
On Friday, UN nuclear inspectors in talks with Iran will again press for access to the Parchin complex, a major military facility, but Western diplomats and experts say the chances of finding any evidence of suspected atom bomb research may have dimmed because the site has been "cleaned up."
Visiting the complex has become a priority for the International Atomic Energy Agency as it seeks to end what the West sees as prolonged Iranian stonewalling of its investigation into allegations of attempts to design a nuclear weapon.
Citing satellite images, Western diplomats say Iran has demolished some small buildings and moved earth at Parchin in an apparent attempt to purge any incriminating evidence from a site where the IAEA believe tests in a steel chamber relevant to nuclear arms were carried out, possibly a decade ago.
"I have heard that there is currently a lot of clean-up going on at Parchin," one envoy said, who like other diplomats said such work was only spotted after the IAEA mentioned Parchin in a detailed report late last year.

JPost.com