VIENNA (Reuters) - ....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. "
Iran holds enough uranium for bomb By Daniel Dombey in Washington
Published: February 19 2009 21:18 | Last updated: February 20 2009 00:51
Iran has built up a stockpile of enough enriched uranium for one nuclear bomb, United Nations officials acknowledged on Thursday.
In a development that comes as the Obama administration is drawing up its policy on negotiations with Tehran over its nuclear programme, UN officials said Iran had produced more nuclear material than previously thought.
They said Iran had accumulated more than one tonne of low enriched uranium hexafluoride at a facility in Natanz.
If such a quantity were further enriched it could produce more than 20kg of fissile material – enough for a bomb.
"It appears that Iran has walked right up to the threshold of having enough low enriched uranium to provide enough raw material for a single bomb," said Peter Zimmerman, a former chief scientist of the US Arms Control and Disarmament Agency
The new figures come in a report from the International Atomic Energy Agency, the UN's nuclear watchdog, released on Thursday. This revealed that Iran's production of low enriched uranium had previously been underestimated.
When the agency carried out an annual stocktaking of Natanz in mid-November Iran had produced 839kg of low enriched uranium hexafluoride – more than 200kg more than previously thought. Tehran produced an additional 171kg by the end of January.
"It's sure certain that if they didn't have it [enough] when the IAEA took these measurements, they will have it in a matter of weeks," Mr Zimmerman said.
Iran's success in reaching such a "breakout capacity" – a stage that would allow it to produce enough fissile material for a bomb in a matter of months – crosses a "red line" that for years Israel has said it would not accept.