North Korean Nuclear Capability

Sarkis Agaian
March 21, 2011

Submitted as coursework for Physics 241, Stanford University, Winter 2011


A desolate nation of approximately 23 million people, the Democratic People's Republic of Korea (DPRK) is a single-party state governed under the mantra of "Songun Chongch'i" or military-first politics. [1] Under this ideology, the DPRK has dedicated its resources to growing and maintaining one of the largest armies in the world, with an estimated active duty military force of 1.1 million personnel, almost double the size of South Korea's military. [2] Tense relations between North Korea and its southern neighbor have made the border between the two countries one of the most heavily militarized in the world. [2] Despite its immense army and deadly artillery, North Korea has pursued nuclear weapons as a deterrent against U.S. aggression. [3] The following reviews what North Korea's nuclear capabilities are and how they were developed under the cover of a civilian fuel cycle.

Nuclear Program

North Korea's pursuit of a civilian fuel cycle has allowed them to experiment with making bomb fuel, with both plutonium and highly enriched uranium (HEU). [3] When Pyongyang launched its own nuclear program, it chose to use a gas-graphite reactor fuel cycle. [4] This choice of fuel cycle was important because gas-graphite reactors can operate with natural uranium fuel and thus do not require the technology for uranium enrichment, technology which the North had not developed at the time. [4]

In 1994, North Korea was forced to stop its plutonium program during the Agreed Framework, in which South Korea, Japan, and the United States agreed to supply two LWRs to the North in exchange for Pyongyang to give up its gas-graphite reactor program. [5] The Agreed Framework did not, however, prevent the North from exploring uranium enrichment. [6] North Korea could have used the enrichment of natural uranium (U-238) for both LEU and HEU. LEU has a lower than 20% concentration of (U-235) and is primarily used in light water reactors to produce nuclear energy. [7] HEU, on the other hand, has a greater than 20% concentration of U-235 and can be used to make bomb-grade uranium. [7] By the early 2000's, Pyongyang is said to have obtained uranium enrichment centrifuge technology from Pakistan's A.Q. Khan and purchased high-strength aluminum tubes suitable for centrifuge rotors from the Russians. [4] Since the Agreed Framework broke down in 2003, North Korea has also conducted three reprocessing campaigns, and is estimated to yield 40-60 kg, of which 24-42 kg are available today for weapons. [6]


North Korea continues to escalate tensions with both its neighboring countries and the United States. [3] Pyongyang boasts that it has become a "proud nuclear power" and threatens to harm the United States if attacked. [5] In this paper we have looked at how North Korea developed its nuclear capabilities under the cover of pursuing a civilian fuel cycle. It is clear that the North has made a lot of progress since the 1980s through its attempts to enrich uranium and produce bomb-grade plutonium. Looking forward, the consequences of North Korea's actions may reach a more global scale. As the North continues to develop its nuclear technology, it may be able to export it to other states such as Iran, which is developing its own nuclear infrastructure, and contribute to global proliferation. [6]

© Sarkis Agaian. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] "North Korea" New York Times, 21 Jan 11.

[2] M. McDonald, "North Korea Boosts Tanks and Special Forces, South Says" New York Times, 30 Dec 10.

[3] W. J. Perry, "Proliferation on the Peninsula: Five North Korean Nuclear Crisis," Ann. Am. Acad. Political Social Sci. 607, 78 (2006).

[4] S. S. Hecker, "Lessons Learned from the North Korean Nuclear Crises," Daedalus, Winter 2010, p. 44.

[5] Larry A. Niksch, "North Korea's Nuclear Weapons Development and Diplomacy," Congressional Research Service Report to Congress RL33590, 5 Jan 10.

[6] S. S. Hecker and W. Liou, "Dangerous Dealings: North Korea's Nuclear Capabilities and the Threat of Export to Iran," Arms Control Today 37 (March 2007).

[7] G. Luft, Energy Security Challenges for the 21st Century: a Reference Handbook (Praeger, 2009), p.297.