Iran has installed two cascades of 164 centrifuges each in its underground nuclear plant, laying a basis for full-scale enrichment of uranium and upping the stakes in a standoff with the West, European diplomats said Monday.

The cascades were to be test-run shortly, without uranium feedstock inside, and fuel material would then be added if the tests were successful, they said.

The 328 centrifuges would be the vanguard of 3,000 planned for installation in the coming months.

Iran recently finished installing piping, electrical cables and other equipment needed to begin so-called "industrial-scale" enrichment in the vast subterranean complex, which is fortified and ringed by anti-aircraft guns in the central Iranian desert.

Diplomats said the installation of the first two cascades was likely to be the gist of Iran's planned announcement of "significant" nuclear progress on Sunday, when it caps anniversary celebrations of its 1979 Islamic Revolution.

"Two cascades have been installed in the underground plant, but they are not yet being run with gas," said a European Union diplomat in Vienna, headquarters of the watchdog International Atomic Energy Agency (IAEA), which has inspectors at Natanz.

"Their plan is to start dry-spinning the cascades within days and then start feeding them with UF6 (uranium feedstock gas)," the diplomat said, alluding to findings during recent visits by IAEA inspectors.

"The Iranians appear to intend to have about six cascades (about 1,000 centrifuges) installed by the spring, and the rest of the 3,000 by around June." Iran plans to rig up a total of 54,000 centrifuges at Natanz in the longer term.

A diplomat from another EU state gave an identical account.

There was no immediate IAEA comment. Such confidential information would be wrapped into a report the IAEA must deliver to the UN Security Council on February 21 on whether Iran has heeded a demand to stop enriching uranium.

Three-thousand centrifuges going nonstop could purify enough uranium for one bomb within a year, assuming Iran wants one.

But analysts say that even if Iran has 3,000 on line in Natanz by June, no sure thing given a litany of previous delays, it may well need another year to iron out technical glitches and a further year to generate usable quantities of nuclear fuel.

(China Daily via agencies February 6, 2007)