Iran blocks probe into alleged atom bomb work: IAEA

By Mark Heinrich

VIENNA (Reuters) - Iran has blocked a U.N. inquiry into whether it researched ways to make a nuclear bomb, the U.N. nuclear watchdog said on Monday, as Britain said it would push hard for tougher sanctions against Tehran.

A confidential IAEA report said Iran had raised the number of centrifuges enriching uranium by 500 to 3,820 since May and was stepping up development of an advanced model able to refine nuclear fuel 2-3 times faster, in defiance of U.N. resolutions.

But a senior U.N. official familiar with the International Atomic Energy Agency findings said Iran seemed a good two years away from enriching enough uranium for an atomic weapon, if it eventually chose to do so.

Iran denies its nuclear work is aimed at developing a bomb.

"On the issue of possible military dimensions to Iran's nuclear programme, we have arrived at a gridlock. Without Iran's assistance and cooperation, we cannot move forward," said a second senior U.N. official.

Iran blamed the IAEA for the impasse. A senior Iranian official, who declined to be named, called on the IAEA to change its approach and work in a "legal and logical" manner.

Britain accused Iran of showing "contempt for the IAEA by continuing to refuse to respond" to IAEA Director Mohamed ElBaradei's serious concerns about possible covert bomb work.

"We will therefore push hard for further U.N. sanctions in the coming weeks," a British Foreign Office statement said.

Iran has withstood limited sanctions imposed so far and may count on Russia, at odds with Western powers over Georgia, to hold up harsh action by the U.N. Security Council, analysts say.

DEBATING THE REPORT

The IAEA report will be debated by the body's 35-nation board of governors at talks starting on Sept 22, with the possibility Western powers might seek a resolution against Iran.

Iran had stockpiled 480 kg (1,050 pounds) of low-enriched uranium so far, the report by the Vienna-based IAEA said.

It would need 1,700 kg (3,740 pounds) to convert into high-enriched uranium (HEU) for fuelling an atom bomb, said U.N. officials who spoke on condition of anonymity.

"That would be a significant quantity, one unit of HEU, and would take on the order of two years," said one official.

Still, the report showed Iran had markedly accelerated its pace of enrichment, with centrifuges now running at around 85 percent capacity compared with 50 percent in May, U.S. nuclear analyst David Albright said in a commentary.