* Iran has uranium for several bombs if refined much more
* But Tehran faces big technical hurdles to actual nuclear
* Islamic state rejects allegations, says nuclear work
* U.S. sees no Iranian decision yet to pursue nuclear arms
By Fredrik Dahl
VIENNA, Oct 2 Iran already has enough
low-enriched uranium for several atomic bombs if refined to a
high degree but it may still be a few years away from being able
to build a nuclear-armed missile if it decided to go down that
Israel's warning last week that Iran will be on the brink of
developing a nuclear weapon by mid-2013 seemed to refer to when
it could have a sufficient stock of higher-grade uranium to make
a quick dash to produce a bomb's worth of weapon-grade material.
But, analysts say, Tehran would need time also for the
technologically complicated task of fashioning highly refined
uranium gas into a nuclear warhead small enough to fit on a
missile - if it opts for such weapons of mass destruction.
"If they haven't worked out all the steps with dummy
materials beforehand they will have a lot to do," said a
Vienna-based diplomat who is not from one of the six world
powers involved in diplomacy over Iran's disputed nuclear
"Maybe they have all of the equipment ready. Maybe they have
played with surrogate materials. I don't think anyone knows."
Experts stress that timeline estimates are fraught with
uncertainty as it is unclear how advanced the Islamic Republic
may be in its suspected nuclear bomb research.
"I still think that we are talking about several years ...
before Iran could develop a nuclear weapon and certainly before
they could have a deliverable nuclear weapon," said Shannon
Kile, head of the Nuclear Weapons Project of the Stockholm
International Peace Research Institute, a think-tank.
Iran rejects suspicions of a covert quest for atomic bomb
capability. But its refusal to curb nuclear work with both
civilian and military applications, and its lack of openness
with U.N. inspectors, have drawn tough Western sanctions.
A high-level group of U.S. security experts - including
former national security adviser Zbigniew Brzezinski and former
Deputy Secretary of State Richard Armitage - estimated that Iran
would need between one and four months to produce enough
weapons-grade uranium for a single nuclear device.
"Additional time - up to two years, according to
conservative estimates - would be required for Iran to build a
nuclear warhead that would be reliably deliverable by a
missile," they said in a report published last month.
Mark Fitzpatrick, of the International Institute for
Strategic Studies (IISS) think-tank, also said Iran would need
at least two years for assembling a nuclear-tipped missile.
Senior researcher Greg Jones of the U.S.-based
Nonproliferation Policy Education Center put forward a much
quicker breakout scenario for any bomb bid and suggested a truck
rather than a missile could be used for delivery to target.
Iran could refine uranium for a nuclear weapon in 10 weeks
and produce the required non-nuclear components in six months or
less, he said, adding this could be done simultaneously.
NO BREAKOUT WITH JUST ONE BOMB?
But the IISS argued in a report last year that the
weaponisation time must be added to that required to produce the
fissile material to calculate when a usable bomb could be made.
Making the actual weapon entails converting uranium gas to
metal, designing a nuclear triggering device and the production
and fitting of spherical explosive lenses, it said.
The United Nations' International Atomic Energy Agency
(IAEA) last year published a report with a trove of intelligence
indicating past, and some possibly continuing, research
activities in Iran that could be relevant for nuclear weapons.
They included suspected high explosive experiments and
possible work on designing a device to produce a burst of
neutrons for setting off a fission chain reaction.
"The information indicates that prior to the end of 2003 the
activities took place under a structured programme; that some
continued after 2003; and that some may still be ongoing," the
IAEA said in its latest report on Iran, issued in late August.
Washington still believes that Iran is not on the verge of
having a nuclear bomb and that it has not made a decision to
pursue one, U.S. officials said in August.
Israel, believed to have the Middle East's only nuclear
arsenal, has threatened military action to stop Iran obtaining
such weaponry, although Prime Minister Benjamin Netanyahu last
week signalled any attack was not on the cards this year.
In a speech at the annual United Nations General Assembly on
Thursday, Netanyahu drew a "red line" on a cartoon bomb just
below a label in which Iran was 90 percent along the path to
having sufficient weapons-grade material.
Experts put that at the point when Iran has amassed enough
uranium, purified to a fissile level of 20 percent, that could
quickly be enriched further and be used to produce a bomb.
Iran has produced more than 6.8 tonnes of uranium refined up
to 5 percent since 2007, an amount experts say could be used for
about five nuclear weapons if processed much further.
Worryingly for the West and Israel, some of that material
has been refined to 20 percent, representing most of the effort
involved in reaching potential bomb material.
According to the latest IAEA report, Iran has produced about
190 kg of this higher-grade uranium, about half of which has
been earmarked for conversion into research reactor fuel,
leaving a stockpile in August of just over 90 kg.
Traditionally, about 250 kg is estimated to be needed for a
bomb, but some believe less would do.
"It is widely known that even a first device can be made
with much less," the diplomat in Vienna said. But, "no one
breaks out to make one warhead. Estimates vary but most think
three to five warheads is a minimum to be a real nuclear power."
An Israeli official briefed on the Netanyahu government's
Iran strategy told Reuters: "Once Iran gets its first device, no
matter how rudimentary, it's a nuclear power and a nuclear
menace. With that said, we have always noted that, from this
threshold, it would take Iran another two years or so to make a