VIENNA, - A UN nuclear agency report due this week is
expected to show Iran further increasing its capacity to produce material that
its adversaries fear could eventually be put to developing atomic bombs, Western
diplomats said on Tuesday.
But they said it is also likely to indicate
that growth in Iran's most sensitive nuclear stockpile has been held back
because some of it has been used for reactor fuel, potentially providing more
time for diplomacy between Iran and major powers.
Tehran's holding of
medium-enriched uranium gas is closely watched in the West as Israel - which has
threatened air strikes if diplomacy and sanctions do not stop Iran's atomic
drive - says it must not amass enough for one bomb if further
Critics say Iran is trying to achieve the capability to make
atomic arms. Iran denies this, saying it needs nuclear power for energy
generation and medical purposes and that it is Israel's reputed nuclear arsenal
that threatens regional peace.
The next quarterly report on Iran's
nuclear program by the UN International Atomic Energy Agency (IAEA),
expected on Wednesday, is likely to show continued installation of the
centrifuges used for enriching uranium, diplomats said.
include an advanced model known as IR-2m which, once operational, would enable
Iran to speed up sharply its accumulation of refined uranium, which can have
both civilian and military purposes.
The number of IR-2m centrifuges and
empty centrifuge casings that have been put in place at Iran's main enrichment
site near the town of Natanz is expected to have risen significantly since
February, when it stood at 180, they said.
Iran has for years been trying
to develop centrifuges more efficient than the erratic 1970s-vintage IR-1
machines it now uses, but introducing new models has been dogged by technical
hurdles and difficulty in obtaining key parts abroad.
"We expect that
they've continued to install more advanced centrifuges at Natanz," one diplomat
Another Western envoy said Iran was also believed to be pressing
ahead in the construction of a research reactor, which experts say could offer
it a second way of producing material for a nuclear bomb, if it decided to
embark on such a course.
Nuclear analysts say the type of reactor that
Iran is building near the town of Arak could yield plutonium for nuclear arms if
the spent fuel is reprocessed, something Iran has said it has no intention of
Diplomats will also scrutinise the IAEA report
for what it has to say about Iran's possession of medium-enriched uranium as
this represents a technical threshold relatively close to the level required for
Since Iran in 2010 began processing uranium to a fissile
concentration of 20 percent it has produced more than the 240-250 kg that would
be needed for one bomb, if refined more.
But while the stockpile has
expanded, Iran has still kept it below Israel's stated "red line" by converting
a large part of the uranium gas into oxide powder in order, Tehran says, to
yield fuel for a medical research reactor in the capital.
As a result,
the increase in the holding of 20 percent gas has been less than the production.
In February, the stockpile was 167 kg, a rise of roughly 18-19 kg since the
previous report in December but a significant slowdown from a 50 percent jump in
the previous three-month period.
"It seems that they are converting
nearly all the material that they are producing," a Western official
But while the uranium conversion activity may postpone any decision
by Israel on whether to strike Iranian nuclear sites, Western diplomats made
clear Tehran must do much more in order to allay suspicions about its atomic
Turning uranium gas into oxide powder in order to make fuel
plates may also be just a temporary positive development because the process is
possible to reverse, Western experts say.
The six world powers involved
in diplomacy with Iran - the United States, Russia, France, Britain, Germany and
China - want it to stop refining uranium to 20 percent and suspend work at the
underground Fordow site where most of this work is pursued.