Iran Worked to ‘Miniaturize’ Weapon Design

By Jonathan Tirone and Margaret Talev - Nov 9, 2011 6:51 AM GMT+0700

Iran continued working on nuclear weapons at least until last year, including efforts to shrink a Pakistani warhead design to fit atop its ballistic missiles, a report from United Nations inspectors said.

The International Atomic Energy Agency, drawing on evidence collected over eight years, reported yesterday that Iran carried out “work on the development of an indigenous design of a nuclear weapon including the testing of components.”

The IAEA document shows that Iran worked to redesign and miniaturize a Pakistani nuclear-weapon design by using a web of front companies and overseas experts, according to the report and an international official familiar with the IAEA’s investigation.

Such a warhead could be mounted on Iran’s Shahab-3 missile, which has the range to reach Israel, according to the report.

The IAEA report adds to international pressure on Iran to answer questions about its program. It was released amid reports in Israeli media that Prime Minister Benjamin Netanyahu is pressing his Cabinet to support possible military action to halt Iran’s nuclear program.

The U.S. may pursue additional sanctions against Iran following release of the report and is waiting to see how Iran responds, according to two U.S. officials who briefed reporters on condition of anonymity. Iran already is under UN sanctions and the U.S. has put sanctions on Iranian government agencies, financial institutions and government officials.

Sporadic Development

The administration officials said the IAEA’s conclusions don’t conflict with U.S. intelligence estimates that Tehran’s government scaled back nuclear weapons development in 2003 while maintaining capability to resume. The officials said Iran’s nuclear weapons efforts have proceeded sporadically since 2003 and that the U.S. believes advancement since then hasn’t been dramatic.

In its report, the international agency said, “some activities relevant to the development of a nuclear explosive device continued after 2003” and “some may still be ongoing.”

Until now, atomic inspectors had only voiced concerns publicly about the “possible existence” of weapons work in Iran.

State-run PressTV said Iran “has rejected” the IAEA report as “unbalanced and politically motivated.” Iran has told IAEA inspectors that evidence used against the Persian Gulf country was forged.

The agency’s report brought calls in the U.S. for tougher action against Iran.

Call for Action

It’s “further proof that the U.S. and other responsible nations must take decisive action to stop the regime from acquiring a nuclear capability,” said U.S. Representative Ileana Ros-Lehtinen, a Florida Republican who is chairman of the House Foreign Affairs Committee.

The IAEA report also “could increase the risk of a military attack on Iran’s nuclear facilities” and therefore “justified a certain risk premium on the price of oil,” Commerzbank wrote today in a research note. Crude oil for December delivery rose $1.28 to $96.80 a barrel on the New York Mercantile Exchange, the highest settlement since July 28. Futures are up 5.9 percent this year.

Iran worked on high explosives design and the development of a neutron generator, the part of an atomic bomb that starts a nuclear chain reaction, according to the senior international official.

Four-Year Program

“Iran embarked on a four-year program, from around 2006 onwards, on the further validation of the design of this neutron source,” the IAEA report said, citing one member state that shared information with inspectors.

The IAEA revealed details of “large-scale high explosives” experiments conducted near Marivan in 2003. The experiments, which drew on technology shared by a Russian nuclear scientist, would have helped Iran calibrate the explosive impact of a bomb’s uranium core, according to the report.

“The information comes from a wide variety of independent sources, including from a number of member states, from the agency’s own efforts and from information provided by Iran itself,” the report said.

It is the first time that the IAEA has published a comprehensive analysis of Iran’s nuclear-weapons work. Data before 2003 is more comprehensive than information seen thereafter, according to the senior official. The Vienna-based agency shared a copy of the information with Iranian authorities before the report was published, the official said.

Uranium Supply

Iran increased its supply of 20 percent-enriched uranium to 73.7 kilograms from 70.8 kilograms reported in September at a pilot nuclear facility in Natanz about 300 kilometers (186 miles) south of Tehran, the IAEA said. Iran has produced 4,922 kilograms of uranium enriched to less than 5 percent compared with 4,543 kilograms in the last IAEA report.

About 630 kilograms of low-enriched uranium, if further purified, could yield the 15 kilograms to 22 kilograms of weapons-grade uranium needed by an expert bomb maker to craft a weapon, according to the London-based Verification Research, Training and Information Center, a non-governmental observer to the IAEA that is funded by European governments.

To contact the reporters on this story: Jonathan Tirone in Vienna at jtirone@bloomberg.net; Margaret Talev in Washington at mtalev@bloomberg.net

To contact the editor responsible for this story: Mark Silva at msilva34@bloomberg.net