WASHINGTON — Western and U.N. nuclear officials are evaluating a secret Iranian technical document that appears to show the country’s nuclear scientists testing a key component used in the detonation of a nuclear warhead, according to intelligence officials and weapons experts familiar with the document.
The document, if authenticated, could rank as one of the strongest pieces of evidence pointing to a clandestine Iranian effort to build nuclear weapons, said former intelligence officials and weapons experts. They were responding to a published report of alleged sophisticated research by Iran on one of the final stages in the construction of a nuclear device.
Excerpts from the technical paper, first reported on the Times of London Web site late tonight, detail a four-year program by Iranian scientists to develop and test a neutron initiator, a device used to trigger a nuclear explosion.
Although the document is undated, the Times quoted foreign intelligence officials as saying it was written in 2007, more than four years after U.S. intelligence agencies believe Iran stopped research on a nuclear warhead.
“It looks bad — there is no doubt about it,” said David Albright, a former inspector with the International Atomic Energy Agency, the U.N. nuclear watchdog, who reviewed the document and other papers for the London newspaper. He said work on a neutron initiator is a “very strong indicator of nuclear work.”
The CIA had no immediate comment on the report. Former U.S. intelligence officials said the document must be evaluated and accurately dated before any conclusions can be drawn. But one former Iran specialist said the paper would be tantamount to a “smoking gun.”
“A neutron initiator is a term of art specific to nuclear weapons design,” said Art Keller, a former case officer with the CIA’s counterproliferation division. “If they are working on a neutron initiator, as the article described, they’re definitely working on bomb design.”
Albright, president of the Institute for Science and International Security, a highly respected Washington research group that studies nuclear proliferation, said the Iranian document describes a program of experiments using uranium deuteride as a neutron source. Other countries, including Pakistan, used the same material in their nuclear weapons program, he said.
The document is written in Farsi under the title “Outlook for Special Neutron-Related Activities Over the Next Four Years,” Albright said. He added that IAEA officials had been aware of the document and are studying its implications.
While troubling, the leaked paper does not conclusively prove that Iranian leaders have decided to build a nuclear device, he said. “The question is whether this is a full-blown weapons effort or just Iran getting its (research) ducks in a row,” he said.
A landmark U.S. intelligence report in 2007 concluded that Iran had conducted secret research on building a nuclear weapon until 2003, when its leaders stopped the effort in response to international pressure.
Some European and Middle Eastern analysts point to evidence that Iran resumed the secret research in 2005. Iran never suspended its work on making enriched uranium, one of the most difficult challenges in building the bomb. Tehran says the uranium will be used to fuel nuclear power plants.