Vienna: The UN atomic agency has found evidence at an underground bunker in Iran that could mean the country has moved closer to producing the uranium threshold needed to arm nuclear missiles, diplomats said on Friday.
The International Atomic Energy Agency has found traces of uranium enriched up to 27 percent at Iran`s Fordo enrichment plant, the diplomats said.
That is still substantially below the 90-percent level needed to make the fissile core of nuclear arms.
But it is above Iran`s highest-known enrichment grade, which is close to 20 per cent, and which already can be turned into weapons-grade material much more quickly than the Islamic Republic`s main stockpile, which can only be used for fuel at around 3.5 per cent.
The diplomats, who demanded anonymity because their information is privileged, said the find did not necessarily mean that Iran was covertly raising its enrichment threshold toward weapons-grade level.
They said one likely explanation was that the centrifuges that produce enriched uranium initially over-enriched at the start as technicians adjusted their output.
Calls to Ali Asghar Soltanieh, Iran`s chief delegate to the IAEA, were rejected and the switchboard operator at the Iranian mission said he was not available. IAEA media officials said the agency had no comment.
Iran is under several rounds of UN sanctions for its failure to disclose information on its controversial nuclear programme.
Tehran says it is enriching uranium to provide more nuclear energy for its growing population, while the US and other nations fear that Iran doing that to have the ability to make nuclear weapons.