The U.N.'s International Atomic Energy Agency (IAEA) said in a confidential report circulated to diplomats that Iran planned an industrial-scale test of a uranium conversion facility soon. Washington and its allies are expected to point to the test as proof Iran has its eyes on a nuclear weapon.
The IAEA said Iranian technicians had told its inspectors they planned to convert 37 tons of yellowcake uranium into uranium hexafluoride (UF6), which one Western nuclear expert said could in theory be enough to build five atomic bombs.
Iran insists the only purpose of its nuclear program is the peaceful generation of electricity. It denies having done any uranium enrichment close to the level needed to fuel a power plant, let alone weapons.
The U.N. agency said it "continues to make steady progress in understanding the (Iranian nuclear) program," though its investigation is not complete.
"It is a work in progress," a senior Western diplomat said of the investigation, adding that the IAEA's sixth such report on Iran was "a mixed bag."
The unresolved issues include enriched-uranium particles found in Iran, work on advanced P-2 centrifuges that can make bomb-grade uranium, and suspected Iranian attempts to buy equipment with both military and civilian nuclear applications.
The report will be discussed at a meeting of IAEA Board of Governors in September, when Washington is expected to renew its call for the board to report Tehran to the U.N. Security Council for violating its nonproliferation obligations. However, diplomats at the U.N. say Washington has few supporters.
Enough for Five Crude Bombs
David Albright, a former U.N. weapons inspector and currently president of
the Institute for Science and International Security (ISIS), said Iran's
uranium conversion test could lead to the production of 100 kg (220 lb) of
weapons-grade highly-enriched uranium. Speaking purely hypothetically,
Albright said that if the UF6 was later enriched sufficiently, "it's
roughly enough for about five crude nuclear weapons of the type Iran could
conceivably build."
He said he was surprised at the many unresolved issues in Iran, adding that it
was "difficult to keep track of them all." But he said Washington
could not point to the report as proof of an Iranian weapons program.
"There's nothing in this report that says, 'Gotcha Iran!', no smoking
gun," he said.
Washington reiterated its view of the Islamic republic.
"We continue to believe that they have a clandestine nuclear weapons program," said a U.S. State Department official who asked not to be named.
Iran's foreign ministry spokesman acknowledged that the IAEA report left some questions unanswered but said they were insignificant.
"There are some minor issues remaining which we hope will be solved in the future although some are trying to make a fuss and create a negative atmosphere about Iran," Hamid Reza Asefi said in a statement.
The IAEA praised Iran for providing it with access to sites inside the country and with some information, but chided it for being late with the provision of other information.
"In (some) cases, sufficiently detailed information has been so late that it has not been possible to include an assessment of its sufficiency and correctness in this report," it said.
The agency said it had received enough information about Iran's laser uranium enrichment program and uranium conversion experiments to end its special probes of those issues.
The IAEA also said Iran's explanation for the discovery of traces of highly-enriched uranium (HEU) at the Natanz enrichment plant and Kalaye Electric Company — that the particles came from contaminated machinery purchased abroad and were not enriched in Iran at Natanz or Kalaye — was "plausible."
However, the IAEA said it was still investigating other possible explanations for the uranium traces, which several diplomats said included the possibility that Iran had enriched the uranium itself at a secret location inside the country.
Additional reporting by Francois Murphy in Vienna, Paul Hughes in Tehran
and Arshad Mohammed in Washington