North Korea’s Nuclear Weapons: Technical Issues

Mary Beth Nikitin
Analyst in Nonproliferation

This report summarizes what is known from open sources about the North Korean nuclear weapons program—including weapons-usable fissile material and warhead estimates—and assesses current developments in achieving denuclearization. 

In total, it is estimated that North Korea has between 30 and 50 kilograms of separated plutonium, enough for at least half a dozen nuclear weapons. While North Korea's weapons program has been plutonium-based from the start, in the last decade, intelligence emerged pointing to a second route to a bomb using highly enriched uranium. However, the scope and success of a uranium enrichment program may be limited. Little detailed open-source information is available about the DPRK's nuclear weapons production capabilities, warhead sophistication, the extent of a uranium enrichment program, or proliferation activities. 

Beginning in late 2002, North Korea ended an eight-year freeze on its plutonium production program, expelled international inspectors, and restarted facilities. In September 2005, members of the Six Party Talks (United States, South Korea, Japan, China, Russia, and North Korea) issued a Joint Statement on the verifiable denuclearization of the Korean Peninsula. On October 9, 2006, North Korea conducted a nuclear test, with a yield of less than 1 kiloton. In February 2007, North Korea and the other members of the Six-Party Talks agreed on steps for phased implementation of the 2005 denuclearization agreement. Phase 1 included the shut-down of plutonium production at the Yongbyon nuclear complex in exchange for an initial heavy fuel oil shipment to North Korea. Phase 2 steps included disablement of plutonium production facilities at Yongbyon and a "complete and correct" declaration of DPRK nuclear activities, in exchange for delivery of energy assistance and removal of certain U.S. sanctions. The declaration was submitted in June 2008. Thereafter, President Bush removed North Korea from the Trading with the Enemy Act (TWEA) list and notified Congress of his intent to lift the State Sponsor of Terrorism (SST) designation after North Korea agreed to verification provisions. North Korea did not accept initial U.S. verification proposals, and in September 2008, threatened to restart reprocessing plutonium. U.S. officials announced a verbal bilateral agreement on verification in October 2008, and the Bush administration removed North Korea from the SST List. North Korea soon after said that it had not agreed to sampling at nuclear sites, a key element for verification of plutonium production. The Six-Party Talks have not convened since December 2008. 

North Korea's failed satellite launch on April 5, 2009, which used ballistic missile-related technology, led to U.N. Security Council condemnation. In response, North Korea said it would abandon the Six-Party Talks and restart its nuclear facilities, and asked international and U.S. inspectors to leave the country. North Korea claimed it tested a nuclear weapon on May 25, 2009, which is estimated as larger than the 2006 blast, but still modest. Through its official news agency, North Korea claimed in September 2009 that it was conducting "experimental uranium enrichment" and in November 2009 that it had reprocessed spent fuel at the Yongbyon facility and had begun to weaponize the resulting plutonium. 

Date of Report: January 8, 2010
Number of Pages: 27
Order Number: RL34256
Price: $7.95

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