Recent intelligence shows Iran has been working to produce a missile re-entry vehicle containing a small nuclear warhead for its Shahab missiles and has encountered problems developing a reliable centrifuge system for uranium enrichment, U.S. officials said.
The officials, who discussed the intelligence on the condition of anonymity, said Iran’s new nuclear warhead program includes what specialists call the basic “physics package” for fitting a nuclear bomb inside the nose cone of a missile.
The officials provided details on the program after Secretary of State Colin L. Powell disclosed Nov. 17 that Iran was developing delivery systems for nuclear missiles. Iran has since agreed to halt uranium enrichment under pressure from the International Atomic Energy Agency (IAEA) and three European governments, a deal the Bush administration views skeptically.
The warhead is based on an indigenous Iranian design and is not being built from design information supplied by the covert nuclear network headed by Pakistani technician Abdul Qadeer Khan, who has admitted supplying nuclear goods to Libya, Iran and North Korea, the officials said.
“They are moving ahead with a design for a warhead,” one official said.
Mr. Powell two weeks ago told reporters traveling with him to Santiago, Chile, that the intelligence shows that Iran is “actively working on [nuclear delivery] systems.”
“You don’t have a weapon until you put it in something that can deliver a weapon,” he said.
Other officials said the intelligence revealed that Iranians belonging to the Atomic Energy Agency of Iran were conducting research and testing on development of a nuclear warhead for a missile. The information came from reliable intelligence sources and was not provided by an Iranian opposition group, they said.
In November, the governments of France, Germany and Britain negotiated an agreement with Iran that calls on Tehran to suspend all uranium enrichment. In exchange, Iran received assurances that it will not be brought before the U.N. Security Council for potential sanctions.
Iran demanded that it be allowed to keep 20 centrifuges for research. The IAEA said it will monitor the machines.
U.S. officials said privately that the Iranians appear to be trying to buy time to continue covert work on nuclear weapons. The Bush administration wants to take the issue to the United Nations, where sanctions can be imposed on Iran.
A U.S. official said the Iranians learned from Saddam Hussein’s regime in Iraq not to put all their nuclear programs in a single location. “They have multiple locations that can be used in case one facility is lost,” the official said.
A CIA report made public last week said the U.S. government “remains convinced that Tehran has been pursuing a clandestine nuclear weapons program.”
The program is based on making a nuclear fuel cycle “ostensibly for civilian purposes but with clear weapons potential,” the report said.
Regarding Iran’s uranium enrichment program, the officials said Tehran is having problems with developing a reliable centrifuge “cascade,” a series of hundreds or thousands of machines that spin uranium hexaflouride gas into highly enriched uranium — the key fuel for nuclear bombs, the officials said.
However, the design work is close to completion and once testing is finished on a successful machine, the Iranians will begin large-scale production of centrifuges, they said.
“They just need to make one machine that doesn’t explode when it spins at 7,000 rpm, and then they’ll go into large-scale production,” one official said.
Iran has deployed at least six 620-mile-range Shahab-3 missiles, said the London-based International Institute of Strategic Studies.
U.S. officials think these missiles and future long-range versions will be the main system for the nuclear warheads.
The IAEA, the watchdog group of the United Nations that has been dealing with the Iranian nuclear problem, announced Monday that it has verified most of Iran’s claims about its nuclear material, after months of dissembling by Tehran.
IAEA Director-General Mohamed ElBaradei, in a report to the board made public Monday, said Iran has been working on nuclear activities since the 1980s at various locations and is using several methods for making nuclear fuel.
The report said Tehran has not fully cooperated in explaining its nuclear programs, although Mr. ElBaradei said he has accepted most of Tehran’s explanations for discrepancies.
The White House has disagreed. “Iran has time and time again deceived and denied, deceived the international community,” White House spokesman Scott McClellan said Tuesday.
The IAEA report said that Iranians had provided false statements and conflicting responses to questions about the program, and that unanswered questions remain about Iran’s uranium enrichment and its importation of centrifuges.