Reuters wrote:Iran boosts nuclear work in bunker - diplomats
(Reuters) - Iran is believed to be expanding uranium enrichment activity deep inside a mountain, diplomatic sources said on Monday, a move likely to add to tension with Western powers that suspect Tehran is seeking nuclear weapons capability.
The move to increase sensitive nuclear work at the Fordow underground site near the Shi'ite Muslim holy city of Qom, even if expected, underlines the Islamic state's defiance in the face of intensifying Western pressure to curb such activity.
Iran last month confirmed it had begun refining uranium to a fissile concentration of 20 percent at Fordow, shifting its highest-grade enrichment from an above-ground location to better protect it against any strikes by Israel or the United States.
Washington, which has not ruled out military action against Iran if diplomacy fails to resolve the long-running nuclear dispute, on January 9 denounced the start-up of the Fordow plant as a further escalation of Iran's "ongoing violations" of U.N. resolutions.
At that time, diplomats said Iran was operating at Fordow two so-called cascades, each of 174 centrifuges - machines that spin at supersonic speed to increase the ratio of the fissile isotope. More centrifuges were being installed, they said.
Enriched uranium can have both civilian and military uses.
One Vienna-based diplomat said two more cascades, like the first pair connected with each other to make the process more efficient, had now also been deployed to enrich uranium.
"The second set of cascades is operational ... my understanding is they are both operational and (have) no problems," the diplomat said.
Another diplomat accredited to the IAEA also painted a picture of expanding activity at Fordow, without giving details.
Neither Iran nor the International Atomic Energy Agency (IAEA), the Vienna-based U.N. agency that regularly inspects Iranian nuclear sites including Fordow, was immediately available for comment.
Iran said last year that it would transfer its highest-grade uranium refinement work to Fordow from its main enrichment plant at Natanz, and sharply boost capacity.
The decision to move work which the U.N. Security Council has called on Iran to suspend to an underground facility could further complicate diplomatic efforts to resolve the standoff peacefully...(continued at link)