By Glenn Kessler
Washington Post Staff Writer
Saturday, June 21, 2008
The United States in recent weeks has obtained new intelligence -- fresh traces of highly enriched uranium discovered among 18,000 pages of North Korean documents -- that are raising new questions about whether Pyongyang pursued an alternative route to producing a nuclear weapon, according to sources familiar with the intelligence findings.
Officials at the State Department and with the director of national intelligence declined to comment on the new information, but sources said Secretary of State Condoleezza Rice made an oblique reference to it in a speech on North Korea policy to the Heritage Foundation on Wednesday.
"As we've gotten deeper into the process, we've been troubled by additional information about North Korea's uranium-enrichment capability," Rice said. "And this information has reaffirmed skepticism about dealing with North Korea."
The new intelligence arrived at an awkward moment for the Bush administration. North Korea next week plans to submit its long-awaited declaration on its nuclear programs, which is expected to disclose that its nuclear reactor at Yongbyon produced about 37 kilograms of plutonium. Then, on June 27 or 28, North Korean officials are expected to blow up the cooling tower attached to the facility, diplomats said.
Plutonium offers a different route to producing a nuclear weapon than uranium enrichment. The Bush administration in 2002 accused North Korea of having a clandestine uranium-enrichment program, based partly on North Korea's large-scale purchases of aluminum tubes. Analysts speculated the tubes could be used as the outer casing for centrifuges needed to spin hot uranium gas into the fuel for nuclear weapons.
Pyongyang has insisted that it had no uranium-enrichment program, even taking an American diplomat in 2007 to a missile factory using the tubes and allowing him to bring home samples in his suitcase.
But late last year, U.S. analysts unexpectedly discovered traces of enriched uranium on the smelted aluminum tubing. Despite months of analysis, intelligence officials have been unable to determine whether the tubes acquired traces of uranium as part of an active enrichment program or were contaminated by exposure to other equipment.
Pakistan, for instance, has acknowledged providing North Korea with a sample centrifuge kit, and so the tubes might have acquired the enriched uranium from the Pakistani equipment. In 2003, inspectors from the International Atomic Energy Agency detected traces of enriched uranium at an Iranian nuclear facility and determined that the material came from Pakistani equipment provided by a nuclear smuggling network.
Now, the fresh samples of enriched uranium complicate the issue. Sources said that traces of highly enriched uranium were found on the 18,000 pages of Yongbyon reactor records provided by North Korea to the United States last month. North Korea provided the documents, which date back to 1987, to help the Bush administration verify the amount of plutonium it produced in the reactor. But the documents have become central to the debate over Pyongyang's possible enrichment activities.
The uranium enrichment data are preliminary, though at least one source familiar with the intelligence said experts had concluded it did not come from Pakistan. Other sources, however, said there was still a dispute on that question. Analysts also do not know how the documents might have been handled and how they could have come into contact with a possible enrichment program.
Last year, U.S. officials played down the 2002 intelligence that North Korea had an uranium-enrichment program, suggesting that North Korea might have tried to start such a program but did not get far. But the public comments have shifted in recent months.
"They have been either seeking or have gotten or have done something on the highly enriched uranium side," Rice said Thursday in an interview with the Wall Street Journal editorial board that was released by the State Department yesterday. "The problem is we don't actually know what they've done. I will tell you that the more we dig into it and the more we actually talk to them about it, the more concerning it is."