WASHINGTON -- Administration officials say that the first specialists to conduct a detailed survey of North Korea's nuclear installations have confirmed that the country has been building a large plutonium reprocessing plant but that the inspectors have so far found no evidence that enough nuclear material has been produced to make an atomic bomb.
The preliminary findings, expected to be announced in Vienna at a meeting of the International Atomic Energy Agency that begins today, cast doubt on the CIA's worst-case estimates that the hard-line Communist government could become a nuclear power within a year.
But some U.S. military and intelligence officials, deeply suspicious of North Korea's sudden willingness to allow inspectors into its most secret installations, say there is circumstantial evidence to suggest that another "pilot plant" for extracting plutonium is hidden underground.
A detailed report circulated before the Vienna meeting by Hans Blix, the director general of the international atomic agency, says senior North Korean officials told him they would abandon their reprocessing effort if Japan, South Korea or Western nations would assure a supply of nuclear fuel and technology that would allow North Korea to build civilian nuclear power plants.
The report, which had a limited distribution but is not classified, is based on Mr. Blix's trip to Pyongyang in May to make arrangements for the first visits by the inspectors.
U.S. officials say that North Korea's offer amounts to a virtual reversal of the nation's earlier, vociferous contention that it is not building a major reprocessing plant, which would allow it to convert nuclear waste into bomb-grade material.
Under an agreement with South Korea reached late last year, both countries agreed never to build reprocessing plants.
"They are moving toward an admission that they have had a bomb project under way, but they are trying to save face," said a senior Defense Department official deeply involved in monitoring the North Korean effort. "It tells you that the pressure is working."
North Korea's nuclear program has been a source of concern to the United States. Especially worrisome is the nuclear complex at Yongbyon, about 60 miles north of Pyongyang.
Suspicions that North Korea is trying to develop atomic weapons have centered on the vast installation, which includes several nuclear reactors and buildings that military experts say are part of a weapons program.
Although there is general agreement among U.S. specialists that Yongbyon houses a reprocessing plant, an essential element for making bomb fuel, there is still considerable disagreement over North Korea's intentions and how far the project has come.