Current Status: On October 9, 2006, the Democratic People's Republic of Korea or DPRK (the official name of North Korea) conducted its first test of a nuclear weapon.The bomb was of a low yield, estimated between 0.2 and 1 kiloton. In June 2006 the Institute for Science and International Security had estimated 20 to 50 kg of separated (and therefore usable) plutonium, enough for 4 to 13 weapons. Shortly after the test, Sharon Squassoni estimated in CRS Report RS21391 that North Korea has 36 to 51 kg of plutonium, enough for 8-10 weapons.

There is no unclassified intelligence estimating whether or not North Korea has a reliable weapons system for delivering nuclear weapons.

Plutonium Program: Currently, all of North Korea's plutonium is produced at a single power plant, the 5MWe (megawatt) nuclear reactor in Yongbyon. The plant began operating in 1986; it is estimated to produce 5 to 7 kg of usable plutonium annually, enough for a single nuclear weapon.The IAEA observed the reactor core being discharged in 1994, but suspected it had been discharged previously. Prior to 1994, up to 10 kg of plutonium may have been separated, including 1kg from another reactor, now not operating (Albright). Plutonium production was suspended when the 5MWe plant was frozen under the Agreed Framework of 1994.

After the collapse of the Agreed Framework in 2003, the DPRK resumed plutonium production. North Korea claims to have extracted plutonium from the 8000 fuel rods that were sealed by inspectors under the Agreed Framework in 1994.An unofficial delegation visiting Yongbyon in 2004 observed that the fuel rods had been removed from the cooling pond and commented that moving them to dry storage would have been dangerous. They were unable to confirm if extraction had taken place.It is estimated that North Korea could have extracted 25 to 30 kg of plutonium from these fuel rods, enough for 4 to 6 weapons.

North Korea had two other nuclear reactors under construction prior to the 1994 Agreed Framework: another reactor at Yongbyon, rated at 50MWe, and a more sophisticated and powerful reactor in Taechon, rated at 200MWe. Although little progress has been made in their reconstruction since 2003, North Korean officials have expressed their intent to continue producing plutonium unless and until an agreement can be reached. According to U.S. Intelligence estimates these two reactors could produce up to 275kg of plutonium annually if they ran at full capacity (Squassoni).

Nuclear Test: The nuclear test was conducted in an underground facility in northeastern North Korea. According to various seismic measurements, the explosion had a yield of between 0.2 to 1 kilotons. In comparison, the first nuclear tests of the United States, China, and the former Soviet Union had yields of about 20 kilotons.

Peter Hayes and Jungmi Kang proposed several theories regarding the low yield of North Korea's first nuclear test. The DPRK's design may have been flawed and therefore not as efficient as it could be, a reasonable assumption for a first test. Or the North Koreans may have feared the underground facility could not contain a large explosion, and thus limited the size to an amount they were confident could be safely tested. A third possibility is that the DPRK wanted to conserve its usable plutonium. A final theory suggests that North Korea has already advanced to the stage of testing small yield weapons that can be mounted as a missile warhead.

In early January 2007, speculation began about North Korean preparations for a second nuclear test. However no additional nuclear test has been conducted at this time.

Uranium Enrichment Program: There is not substantial information about the DPRK's reported pursuit of a uranium enrichment program. While many U.S. intelligence officers seem to agree that North Korea pursed an uranium enrichment program in the late 1990s (during the period of the Agreed Framework), there are varying estimates about when it began and sharp disagreements about the extent of a program.

In October 2002, the US government announced that North Korea admitted to having a covert uranium enrichment program, which the North Korean government later denied. In November 2002, the CIA estimated with high confidence in a report to Congress that "the North is constructing a [uranium enrichment] plant that could produce enough weapons-grade uranium for two or more nuclear weapons per year when fully operational -- which could be as soon as mid-decade."

However, in February 2007, that estimate was reassessed. According to the New York Times, a one-page intelligence assessment partially declassified by the Office of the Director of National Intelligence on February 28 stated that while there is moderate confidence that a DPRK effort to develop a uranium program exists, the "degree of progress towards producing enriched uranium remains unknown." Assistant Secretary of State Chris Hill, testifying before the House that day said that the United States believes that the DPRK has made purchases consistent with the development of an uranium program, but acknowledged that there is not clarity on the extent of any program.

North Korea's Nuclear Weapons Program: Sources and Additional Resources

Albright, David and Brannan, Paul, "The North Korean Plutonium Stock Mid-2006," Institute for Science and International Security (June 26 2006)

Albright, David, "North Korea's Alleged Large-Scale Enrichment Plant: Yet Another Questionable Extrapolation Based on Aluminum Tubes" (February 23, 2007)

"CIA estimate of DPRK Uranium Program [untitled]," provided to Congress November 19, 2002

Hayes, Peter and Kang, Jungmi. "Technical Analysis of the DPRK Nuclear Test." Nautilus Institute (Oct 20 2006)

Hecker, Siegfried S. "Report on North Korean Nuclear Program." Center for International Security and Cooperation, Stanford University (November 15 2006)

Kerr, Paul. "N. Korea's Uranium-Enrichment Efforts Shrouded in Mystery." Arms Control Association (May 2003)

Kerr, Paul. "Deconstructed: North Korea's Nuclear Programs." Arms Control Association (Jan/Feb 2004)

Pinkston, Daniel A. and Sungtack, Shin. "North Korea Likely to Conduct Second Nuclear Test." Center for Nonproliferation Studies (Jan 8 2007)

Niksch, Larry A. "North Korea's Nuclear Weapons Program." U.S. Congressional Research Service. (RL33590; Jan. 3, 2007)

Sanger, David E. and Broad, William J.,"U.S. Had Doubts on North Korean Uranium Drive," The New York Times (March 1, 2007)

Squassoni, Sharon. "North Korea's Nuclear Weapons: Latest Developments." U.S. Congressional Research Service. (RS21391; Oct 18 2006)