Iran seen having problems with nuclear program

WASHINGTON (Reuters) - Iran appears to be encountering technical difficulties with its uranium enrichment but this does not diminish the fact that it has nuclear ambitions and is acting on them, U.S. officials and experts said on Thursday.

"Have they encountered technical difficulties? Absolutely, because this is a very difficult thing to do," Undersecretary of State Robert Joseph, the top U.S. non-proliferation official, told Reuters.

"But there is no sense -- in terms of what we see in the (U.N.) report and the statements of Iranian leaders -- that there is any intentional slowdown," he added.

The International Atomic Energy Agency, or IAEA, the U.N. nuclear watchdog, reported that Iran failed to stop nuclear work by a Thursday deadline, thus clearing the way for possible sanctions by the Security Council due to Western fears Tehran could be trying to make atom bombs.

Iran insists it is only trying to produce nuclear power for electricity, although it hid sensitive research from U.N. inspectors for almost 20 years and has since hindered U.N. investigations.

Drawing on the U.N. report and diplomatic sources, former U.N. weapons inspector David Albright believes that Iran made "limited progress" at its Natanz uranium enrichment plant, installing and operating fewer gas centrifuges than expected.

Centrifuges are rapidly rotating cylinders used for enriching uranium for nuclear fuel.

In a written analysis, Albright said U.S. and IAEA officials expected Iran to have installed five cascades or networks, each with 164 interconnected centrifuges, in a pilot plant at Natanz by August 2006 but "it now appears Iran has not begun to operate the second and third cascades."

The second and third cascades "may be close to completion" but the fourth and fifth cascades appear to be behind, he wrote.

The one operating cascade has not been run consistently over a sustained period, which Iran must do to achieve proficiency, he wrote.

Also, while Iran told the IAEA of plans to begin installing the first 3,000 centrifuges at Natanz's underground halls by the last quarter of 2006, "it now appears that Iran will also not meet this deadline," he wrote.

HIGHLY ENRICHED URANIUM FOUND

Albright, who heads the Institute for Science and International Security think tank, wrote that senior diplomats in Vienna believe it is possible that Iran is deliberately delaying its nuclear work while diplomacy is underway.

But Jacqueline Shire, Albright's associate, told Reuters: "I would put somewhat less stock today in Iran's slowing down for political reasons because of the information in the IAEA that they are continuing to enrich."

The IAEA report said Iran fed uranium hexaflouride, the feedstock for uranium enrichment processes, into the 164-centrifuge cascade for short periods in June, July and August and recently launched a heavy-water production plant.

Inspectors in mid-August found traces of highly enriched uranium, of potential use for atom bombs, in a container at Iran's Karaj Waste Storage Facility, the IAEA said.

Given these developments and Iran's repeated refusal to forsake its nuclear ambitions, the fact that Tehran may have technical difficulties is "cold comfort," State Department spokesman Sean McCormack told a news briefing.

Determinations about Iran's level of nuclear capability are crucial to decision-making by the United States and its partners. U.S. intelligence has said it could be years before Iran produces a weapon, but other experts say Tehran must not be allowed to achieve its target of 3,000 operating centrifuges because that would provide a critical capability.