By R. Jeffrey Smith and Joby Warrick
Washington Post Staff Writer
Monday, December 28, 2009; A02
North Korea has constructed a plant to manufacture a gas needed for uranium enrichment, according to a previously unpublicized account by the father of Pakistan's atomic bomb program, a development that indicates Pyongyang opened a second way to build nuclear weapons as early as the 1990s.
Pakistani scientist Abdul Qadeer Khan also said that North Korea may have been enriching uranium on a small scale by 2002, with "maybe 3,000 or even more" centrifuges, and that Pakistan helped the country with vital machinery, drawings and technical advice for at least six years.
North Korea's nuclear program is among the world's most opaque, and Khan's account could not be independently corroborated. But one U.S. intelligence official and a U.S. diplomat said his information adds to their suspicions that North Korea has long pursued the enrichment of uranium in addition to making plutonium for bombs, and may help explain Pyongyang's assertion in September that it is in the final stages of such enrichment.
Khan's account of the pilot plant, which he says North Korea built without help, is included in a narrative that depicts relations between the two countries' scientists as exceptionally close for nearly a decade. Khan says, for example, that during a visit to North Korea in 1999, he toured a mountain tunnel. There his hosts showed him boxes containing components of three finished nuclear warheads, which he was told could be assembled for use atop missiles within an hour.
"While they explained the construction [design of their bombs], they quietly showed me the six boxes" containing split cores for the warheads, as well as "64 ignitors/detonators per bomb packed in 6 separate boxes," Khan said.Old assumptions
His visit occurred seven years before the country's first detonation, prompting some current and former U.S. officials to say that Khan's account, if correct, suggests North Korea's achievements were more advanced than previously known, and that the country may have more sophisticated weapons, or a larger number, than earlier estimated.
But Siegfried S. Hecker, a former Los Alamos National Laboratory director who was allowed to see some North Korean plutonium during a visit to its nuclear facilities in January 2004, said after hearing Khan's description of the trip he remains unconvinced that the country in 1999 had enough fissile material on hand to make such weapons.
Hecker said Khan may have tried to get himself "off the hook, to say what [he] . . . did was not that bad because these guys already had nuclear weapons. That's a nice way to cover his own tracks."
Since some of Khan's actions were exposed in 2003 and 2004, top Pakistani officials have called him a rogue proliferator. Khan said, however, there was a tacit agreement between the two governments that his laboratory "would advise and guide them with the centrifuge program and that the North Koreans would help Pakistan in fitting the nuclear warhead into the Ghauri missile" -- his country's name for its version of the Nodong missiles that Pakistan bought from North Korea.
Pakistan gave North Korea vital equipment and software, and in return North Korea also "taught us how to make Krytrons" -- extremely fast electrical switches that are used in nuclear detonations and are tightly controlled in international commerce. Contradicting Pakistani statements that the government had no involvement in such sensitive transfers, Khan says his assistance was approved by top political and Army officials, including then-Lt. Gen. Khalid Kidwai, who currently oversees Pakistan's atomic arsenal.
Khan, 73, is under house arrest in Islamabad. He has threatened to disclose sensitive information if he remains in confinement.A contentious issue
The issue of what the hermetic country has been doing with uranium and when it started has been especially contentious since 2002. When an Obama administration envoy, Stephen Bosworth, visited North Korea this month, he "strongly put down a marker" that future talks must include discussion of uranium, a senior U.S. official said.
Pakistani officials in Washington dismissed Khan's assertions as baseless, without responding to questions about Kidwai's role. "Pakistan, as a nuclear weapons state, has always acted with full responsibility and never engaged itself in any activity in violation of the non-proliferation norms," the embassy said in a statement.
Song Ryol Han, the North Korean ambassador to the United Nations, denied that his country had a uranium program before last spring or that it ever discussed the issue "with Dr. Khan in Pakistan." Song said that "only after last April, when the U.S. hostility entered extremely critical stage" did the country start such a program as a "nuclear deterrence" measure.
Khan described his dealings with the country in official documents and in correspondence with a former British journalist, Simon Henderson, who said he thinks an accurate understanding of Pakistan's nuclear history is relevant for U.S. policymaking. The Washington Post independently verified that the documents were produced by Khan.
In his written account, Khan said the capacity of North Korea's plant for making the centrifuge feedstock, a caustic material known as uranium hexafluoride, "initially was two tons per year" and later was raised to 10 tons a year. He did not give the plant's location but said that at one point North Korea sent a kilogram of the gas it had made to Pakistan for testing. He also stated that Pakistan shared a sample of its own gas to be used as a manufacturing standard by the North Koreans.
A U.S. government nuclear expert, speaking on the condition of anonymity because of the sensitivity of the subject, said constructing a plant of this size will probably be seen as "a very serious commitment" to making nuclear arms with a method that is hard to detect. The official noted that the country was obligated to report such facilities under a global treaty to which it was a party until 2003.
Khan said he understood that North Korea's ambition was to produce enriched uranium fuel for an aged reactor because it could not rely on a continuing foreign supply of such fuel. But two officials noted that if North Korea indeed had 3,000 or more centrifuges operating by 2002, which Khan called "quite likely," then work on that scale opens the door to industrial-scale enrichment for weapons as well.
Khan said he negotiated the purchase of 10 Nodong missiles and related technology for $150 million after visiting North Korea in 1994 at the request of Benazir Bhutto, then Pakistan's prime minister, and top army officials. "As a result of this deal, 10 North Korean experts came to Kahuta and were housed within the complex," Khan said, referring to the city in northeastern Pakistan where his laboratory is situated.
Khan said three army staff chiefs approved the stay of the North Koreans, who "were officially allowed to visit all the workshops and meet and discuss freely with the scientists and engineers," including those working on P-1 centrifuges, as well as more advanced models known as P-2s.
After gaining the approval of an army chief and after the payment of funds by North Korea, "I asked my people to prepare 20 outdated P-1 machines and gave them. Since they were working in the plant and were familiar with the P-2 machines, they asked for 4 of these too."Undermining a pledge?
Several former U.S. officials, after being informed of Khan's statements, said they undermine North Korea's 1994 pledge to work with the United States "for peace and security on a nuclear-free Korean peninsula."
"This paints a picture of even more collaboration than I assumed those countries had," said Robert G. Joseph, a prominent critic of the 1994 agreement. Joseph served as the principal nonproliferation official at the White House under President George W. Bush from 2001 to 2005 and then as undersecretary of state for arms control.
Khan said Gen. Pervez Musharraf, the chief of the army staff from 1998 to 2007 and president from 2001 to 2008, and "his right-hand men" -- including Kidwai, Khan asserted -- "knew everything and were controlling incoming and outgoing consignments." Kidwai heads the group that controls Pakistan's arsenal, estimated by some U.S. government analysts at more than 100 weapons.
But Musharraf, in his 2006 autobiography, said that Khan was responsible for all of the nuclear-related exports to North Korea and that "neither the Pakistan Army nor any of the past governments of Pakistan was ever involved or had any knowledge of A.Q.'s proliferation activities."
Staff researcher Julie Tate contributed to this report.