The United States has obtained new intelligence that raises new questions about whether North Korea pursued an alternative route to producing a nuclear weapon, The Washington Post reported in Saturday editions.
Fresh traces of highly enriched uranium were found on 18,000 pages of records from North Korea's Yongbyon reactor that were provided by Pyongyang to the United States last month, the Post said, citing sources familiar with the intelligence findings.
The documents date back to 1987, the Post said. North Korea provided them to help the Bush administration verify the amount of plutonium it produced in the reactor.
The newspaper said 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. On June 27 or 28, North Korean officials are expected to blow up the cooling tower attached to the facility, the Post said.
Plutonium offers a different route to producing a nuclear weapon than uranium enrichment, the Post said. Pyongyang has insisted that it had no uranium-enrichment program.
The new uranium enrichment data is preliminary, the Post said. 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.
