Iran stalls probe into alleged atom bomb research: IAEA

By Mark Heinrich

VIENNA (Reuters) - A U.N. inquiry into intelligence allegations of secret atom bomb research in Iran has reached a standstill because of Iranian non-cooperation, an International Atomic Energy Agency report said on Monday.

"We have arrived at a gridlock," said a senior U.N. official familiar with the latest report, which urged Iran to take the intelligence allegations seriously to defuse suspicions its nuclear work is not entirely peaceful.

The confidential report also said Iran had raised the number of centrifuges enriching uranium to 3,820, compared with 3,300 in May, with over 2,000 more being installed.

But Iran seemed some way from refining enough uranium to build a nuclear weapon, if it chose, the report indicated.

Iran had stockpiled 480 kg (1,050 pounds) of low-enriched uranium so far. It would need 15,000 kg (33,000) to convert into high-enriched uranium 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.

In its last report in May, the IAEA said Iran appeared to be withholding information needed to explain intelligence that it had linked projects to process uranium, test high explosives and modify a missile cone in a way suitable for a nuclear warhead.