U.S. Increases Estimate Of N. Korean Plutonium

By Glenn Kessler
Washington Post Staff Writer
Wednesday, May 14, 2008

U.S. intelligence analysts have prepared a fresh estimate of the size of North Korea's stockpile of plutonium -- larger than previous assessments -- that will be compared with the information contained in 18,822 pages of reactor production records turned over by North Korea last week, according to U.S. officials.

North Korean officials have said about 30 kilograms of plutonium was produced at their five-megawatt reactor at Yongbyon, at the low end of most private and government estimates. The new U.S. estimate is expected to be from 35 to 40 or 50 to 60 kilograms, though sources would not detail how much it had increased from the last government estimate.

"It will be a little more than past estimates," said a senior U.S. official with access to the intelligence. "It solidifies it and presents a more solid assessment."

The official, speaking on the condition of anonymity because he was discussing intelligence matters, said analysts had tried to rescrub previous assumptions about the North Korean program in order to reach the new figure.

A kilogram is 2.2 pounds, and about four to six kilograms are needed for a nuclear weapon. That means the gap between U.S. and North Korean tallies could reflect enough for one or more weapons.

The higher estimate could complicate the State Department's desire to verify North Korea's claims, a key test before President Bush lifts two key sanctions against Pyongyang. North Korea, as part of its nuclear declaration, is supposed to disclose its stockpile of plutonium, and also acknowledge U.S. concerns and evidence on nuclear dealings with Syria and a suspected uranium enrichment program.

Sung Kim, the State Department's director for Korean affairs, told reporters yesterday that reactor documents "are an important first step in terms of verifying North Korea's declaration," which will ultimately include "access to their facilities, sampling, interviews with personnel involved in their programs."

In coming weeks, more than a dozen government experts will pore through the documents, which must be translated from Korean.

The U.S. government has never made public an official estimate of North Korea's plutonium stockpile. In 2006, the Institute for Science and International Security, a Washington-based research organization, estimated that the North Korean facility had discharged 43 to 61 kilograms, but it recovered only 20 to 53 kilograms because of waste and inefficiency.

A key factor in the estimates is whether North Korea had separated as much as 10 kilograms of plutonium before 1992, an issue that has divided the intelligence community. The institute reached the lower end of its estimate by assuming North Korea did not recover the plutonium in that period.

North Korea's reactor had been frozen under a 1994 agreement with the United States, but that deal collapsed in 2002 after the Bush administration charged that Pyongyang had a clandestine project to enrich uranium -- a different route to a nuclear weapon. North Korea has denied it had such a program.

Few details have been revealed about the evidence behind that assertion, but yesterday a high-ranking former intelligence official who reviewed it said it was not convincing.

"I was extremely concerned that people were giving a lot more credence to the evidence" than warranted, Carl W. Ford Jr., former head of the State Department's Bureau of Intelligence and Research, told a gathering at the Carnegie Endowment for International Peace. "Before we make judgments, we ought to have some evidence."

Last year, North Korea provided Kim with samples from aluminum tubes that U.S. analysts said were used in the enrichment program but which Pyongyang said was intended for a missile factory. U.S. experts concluded that those samples contained traces of enriched uranium, suggesting they were intermingled with nuclear-related equipment.

But U.S. analysts are still scrutinizing whether the source was indigenous -- suggesting that the enrichment program operated -- or whether the contamination occurred in Pakistan, which supplied some equipment to North Korea evidently tainted by uranium particles, according to a U.S. official privy to intelligence on the matter.

Staff writer Joby Warrick contributed to this report.

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