Iranian Diagram May Be Plan for Atomic Test Site

Iranian engineers have completed sophisticated drawings of a deep subterranean shaft, according to officials who have examined classified documents in the hands of U.S. intelligence for more than 20 months.

The plans for the 1,300-foot tunnel, with remote-controlled sensors to measure pressure and heat, appear designed for an underground atomic test detonation that might one day announce Tehran’s arrival as a nuclear power, the officials said.

By the estimates of U.S. and allied intelligence analysts, that day remains as much as a decade away, assuming that Iran applies the full measure of its scientific and industrial resources to the project and encounters no major technical hurdles.

But whether Iran’s leaders have reached that decision and what concrete progress the effort has made remain divisive questions among government analysts and U.N. inspectors.

In the three years since Iran acknowledged having a secret uranium enrichment program, Western governments and the United Nations’ nuclear watchdog, the International Atomic Energy Agency, have gathered evidence to test the Tehran government’s assertion that it plans to build nothing more than peaceful nuclear power plants.

Often circumstantial, usually ambiguous and always incomplete, the evidence has confounded efforts by policymakers, intelligence officials and allies to reach a confident judgment about Iran’s intentions and a diplomatic solution to the situation.

Drawings for the tunnel, not disclosed publicly before, appear to U.S. officials to signal at least the ambition to test a nuclear explosive. But U.S. and U.N. experts who have studied them say the undated drawings do not clearly fit into a larger picture. Nowhere, for example, does the word “nuclear” appear on them. The authorship is unknown, and there is no evidence of an associated program to acquire, assemble and construct the components of such a site.

“The diagram is consistent with a nuclear test-site schematic,” one senior U.S. source said, noting that the drawings show a test-control team parked a safe six miles from the shaft. As far as U.S. intelligence knows, the idea has not left the drawing board.

Other evidence is cloaked in similar uncertainty. Contained in a laptop stolen by an Iranian citizen in 2004 are designs by a firm called Kimeya Madon for a facility to produce uranium gas, which would give Iran a stock that could be enriched for fuel or for bombs. Also on the laptop, which was obtained by U.S. intelligence, were drawings on modifying Iran’s ballistic missiles in ways that might accommodate a nuclear warhead.

Meanwhile, an imprisoned Pakistani arms dealer recently offered uncorroborated statements that Iran received several advanced centrifuges, which would vastly improve its nuclear program.

U.S. intelligence considers the laptop documents authentic, but analysts cannot completely rule out the possibility that internal opponents of the Iranian leadership could have forged them to implicate the government, or that the documents were planted by Tehran to convince the West that its program remains at an immature stage.

CIA analysts, some of whom had been involved on the flawed assessments of Iraq’s weapons programs, initially speculated that a third country might have fabricated the evidence. But they discounted that theory.

IAEA inspectors, who were highly skeptical of U.S. intelligence on Iraq, have begun to pursue aspects of the laptop information that appear to bolster previous leads.