WASHINGTON—Iran has advanced its nuclear program to where it will be able to produce weapons-grade fuel in two to four months, nuclear experts and former United Nations inspectors said.
The new assessments feed growing alarm in the U.S., Europe and Israel
that efforts to deny Tehran a nuclear-weapons capability could be
rendered futile by as early as next summer.
Israeli Prime Minister Benjamin Netanyahu told the U.N. General
Assembly last month that the international community needed to be
prepared to strike Iran's nuclear sites by the summer.
Iran denies it is pursuing atomic weapons and says its nuclear work
is solely for civilian purposes. U.S. officials said they believe Iran's
Supreme Leader Ayatollah Ali Khamenei has yet to make the political
decision to acquire a nuclear bomb.
The state of Iran's nuclear program has become a major foreign-policy
issue in this year's U.S. presidential election. Republican candidate
Mitt Romney has charged President Barack Obama with being soft on
confronting Iran. The White House said its sanctions aimed at pressing
Iranian leaders to bend to international demands have fueled a 40% fall
in the value of the Iranian currency in the past two weeks.
The Institute for Science and International Security, an independent
research institute in Washington with former U.N. inspectors on its
staff, concluded in a report this week that Iran could produce enough
highly enriched uranium for one atomic bomb, about 25 kilograms, in two
to four months using its largest uranium-enrichment facility near the
city of Natanz.
The ISIS report offered a faster timeline than Mr. Netanyahu
presented to the U.N. on Sept. 27 because of Tehran's growing stockpile
of higher-enriched uranium and its expanding numbers of centrifuge
machines. The Israeli leader said Iran is expected to have acquired
enough higher-enriched uranium by spring or summer to begin conversion
to weapons grade. He said Iran then could construct its first nuclear
bomb within several weeks or months.
ISIS bases its conclusions almost solely on information released by
the U.N.'s nuclear watchdog, the International Atomic Energy Agency. The
IAEA said in its most recent report in August that Tehran had doubled
its capacity to produce 20% enriched uranium at its underground facility
near the holy city of Qom. But the IAEA didn't offer a timeline for
when Iran might be able to produce weapons-grade fuel.
The think tank said Tehran could combine its stockpiles of
low-enriched and higher-enriched uranium to make a dash for
weapons-grade fuel, which is around 90% purity. The Iranians could do
that by synchronizing the enrichment of these two grades of uranium and
cutting out some intermediary steps that slow the process, ISIS said.
"Growth in the stock of near 20% [purity] reduces the time to break out," ISIS said in its report.
Iran has a stockpile 91.4 kilograms of uranium enriched to 20%
purity, according to the IAEA. An additional 25 kilograms of the
material is committed for conversion into fuel rods for Tehran's
ISIS said its faster estimates for Iran acquiring the highly enriched
uranium would require Tehran to use its total stockpile of 20% enriched
The institute played down Mr.
Netanyahu's assertion that Iran could quickly convert the weapons-grade
fuel into a usable atomic bomb. "Iran would need many additional months
to manufacture a nuclear device suitable for underground testing and
even longer to make a reliable warhead for a ballistic missile," the
U.S. officials believe Iran would need 12 to 18 months to build an
atomic weapon if Mr. Khamenei gives the order. The U.S. intelligence
community concluded in a controversial 2007 report that Tehran had ended
a structured program to build an atomic bomb four years earlier, though
some research is believed to have continued.
IAEA officials have said recently that they believe the suspected
head of Iran's nuclear-weapons studies, scientist Mohsen Fakhrizadeh,
reopened a scientific office last year. And the U.N. agency has been
pressing Iran, so far unsuccessfully, to allow it to visit a military
facility south of Tehran, called Parchin, where the IAEA believes
nuclear-weapons related tests had occurred.
The Obama administration has voiced concerns about the threat posed
by Iran's production of higher-enriched uranium. But U.S. officials have
stressed that the IAEA would detect any moves by Iran to reconfigure
their centrifuge machines to begin producing weapons-grade fuel.
IAEA inspectors visit the sites in Natanz and Qom around twice a month. The agency also has cameras monitoring the sites.
Iran, however, has indicated in recent months that it may further limit its cooperation with the IAEA.
The head of Iran's Atomic Energy Organization, Fereydoun
Abbasi-Davani, charged the Vienna-based agency last month with trying to
sabotage Iran's uranium-enrichment facilities by cutting off
Iran also has accused the IAEA of being complicit in the murders of
five Iranian nuclear scientists over the past five years and spying for
Western countries. The IAEA has denied these charges.
"If the IAEA has to end or limit these inspections, there could be a
serious problem," said Olli Heinonen, a former chief weapons inspector
at the agency, during a presentation on Tuesday in Washington.
Both Mr. Heinonen and ISIS said that the underground facility at Qom
is playing an increasingly central role in Iran's nuclear-fuel
production. The facility is buried deep underground and seen as
potentially impervious to attacks.
Currently, the Qom site is seen as incapable of quickly producing
highly enriched uranium because of the dearth of centrifuges currently
operating there. But the IAEA said in August that over 2,000 machines
could be operating there shortly.
Still, ISIS said in the report that it doesn't expect Iran to "break
out" in the next year, because of the high likelihood that such moves
would be detected by the IAEA and lead to an American or Israeli
"Iran's current trajectory at [the Qom facility] is increasing the
chance of a military confrontation, particularly given growing concern
about the relatively short breakout time," ISIS said.