Nuclear Weapons

Pyongsan Uranium Concentrate Plant (Nam-chon Chemical Complex): Infrastructure Development and Status

Executive Summary

  • The Pyongsan Uranium Concentrate Plant represents a critical component of North Korea’s nuclear research and weapons development programs. Since the closure of the Pakchon Pilot Uranium Concentrate Facility in the mid-1990s, it is the only verified producer of uranium concentrate (yellowcake) in the country.1
  • The plant’s importance can be seen by its consistent receipt of scarce resources to maintain, refurbish, or modernize it since at least 2003.
  • Although the International Atomic Energy Agency (IAEA) has not been able to visit the Pyongsan Uranium Concentrate Plant since 1992, satellite imagery and open source material indicate that the plant is operational. They also indicate it has worked to a relatively steady production tempo suggesting that, barring unforeseen developments, the plant is highly likely to remain active for the foreseeable future.
  • Indeed, expansion to the site’s waste processing infrastructure suggests the site is being readied for increased yellowcake production.
  • Given known North Korean industrial practices, observed waste storage practices, and health and safety concerns raised by defectors and outside observers, there are likely to be numerous health, safety, and environmental issues surrounding the operations (and any decommissioning efforts) at the Pyongsan Uranium Concentrate Plant and its related facilities.
  • The dismantlement of the Pyongsan Uranium Concentrate Plant should be an essential component to any meaningful future “complete, verifiable, irreversible dismantlement” nuclear agreement between the United States and North Korea.

The Pyongsan Uranium Concentrate Plant (38.318369 N, 126.432360 E) is located in Pyongsan-gun (평산군, Pyongsan County), Hwangbuk (황북, North Hwanghae Province), approximately 100 kilometers southeast of the North Korean capital city of Pyongyang and 96 kilometers northwest of Seoul—the capital of South Korea. The plant is co-located with the uranium ore producing January Industrial Mine, which supplies the plant. Since the closure of the Pakchon Pilot Uranium Concentrate Facility (39.710361 125.568141) in the mid- 1990s,2 Pyongsan is the only verified producer of uranium oxide (yellowcake) in the country.3

Although the information remains to be verified, various experts, defectors, and early South Korean sources estimate that the yellowcake produced by the plant contains 80 percent triuranium octoxide (U3O8) by weight—the normally accepted range for yellowcake purity is 70-90 percent.4 According to Hans Blix, then-director general of the IAEA, North Korean personnel told him during his May 1992 familiarization visit that the plant also produces other products including vanadium, nickel, molybdenum and radium—all likely in small quantities—in addition to uranium.5

After converting uranium ore to yellowcake on-site, the yellowcake is shipped to the Yongbyon Nuclear Research Facility. Here, the yellowcake is further processed. According to early-1990s testimony, including that by Chon Chi-pu (described in a 1992 KCTV interview as the chief engineer of Yongbyon Fuel Rod Fabrication Plant) and Kim Tae-ho (a defector who worked on a “wastewater disposal team” at Pyongsan), Pyongsan’s yellowcake is used to produce fuel assemblies for the 5MWe and IRT reactors.6 Today, it appears that Pyongsan also provides the feedstock for the uranium hexafluoride (UF6) that feeds the Yongbyon’s Centrifuge Enrichment Plant.

As the country’s sole confirmed operational producer of yellowcake, Pyongsan occupies a critical role in North Korea’s nuclear research and weapons programs.7 Although it is unclear if the subject was raised during the abortive Hanoi Summit of February 27-28, 2019, the dismantlement of the Pyongsan Uranium Concentrate Plant—and the detailed accounting and safeguarding of its produced material—should be considered an essential component to any meaningful future “complete, verifiable, irreversible dismantlement” nuclear agreement between the United States and North Korea.

Overview image of the Pyongsan Uranium Concentrate Plant, Tailings Pond, and January Industrial Mine (mining complex) – June 13, 2020 (Copyright © 2020 by Airbus)

For this report, during the past year, CSIS analyzed 100+ medium- and high-resolution declassified and commercial satellite images of the Pyongsan Uranium Concentrate Plant, its associated activities and local environs focusing upon changes in existing infrastructure and new developments. The analysis of these images was combined with interview data from regional, national and international experts, defectors, and open source information. It is believed that this resulting report provides a new and unique look into the subject and is one of the most comprehensive collections of unclassified information and satellite imagery presently available. Readers are cautioned, however, that due to the extremely closed nature of society within North Korea and their active programs of camouflage, concealment, and deception, accuracy in any work dealing with the country’s nuclear program is a matter of relatives. Regardless, it is the authors’ hope that this paper provides a firm foundation upon which further study of the subject may be developed. CSIS intends to periodically update this report as new information and satellite imagery becomes available.

Please visit to read the full report.

An addendum containing only the satellite images for the report can be downloaded here.


  1. Please refer to footnote 1 of the full report on to see the list of sources consulted in preparation of this report.
  2. Joseph Bermudez and Victor Cha, “Pakchon Uranium Concentrate Pilot Plant,” August 21, 2019, Beyond Parallel (CSIS Korea Chair), pakchon-uranium-concentrate-pilot-plant/.
  3. Since the late-1990s, there have been occasional private and public reports of additional uranium concentrate and other nuclear-related activities at different locations in North Korea. While it is likely that there are or have been such activities, almost all of the readily available reports have internal inconsistencies, remain to be verified, and should be viewed with caution.

    Although called yellowcake because of the general yellowish color of the final product, it can vary in color from yellow to dark green depending upon the temperature at which it was dried. “Nuclear explained – The nuclear fuel cycle,” EIA, https://www.eia. gov/energyexplained/nuclear/the-nuclear-fuel-cycle.php; “Yellowcake,” NRC, https://

  4. Author interview data; D. M. Hausen, “Characterizing and classifying uranium yellow cakes: A background,” Journal of The Minerals 50, no. 12 (December 1998): 45-47; “Development at ‘Dangerous Point,’” Yonhap, May 9, 1994.

    A declassified Hungarian report from 1979 states, “I heard from the Soviet ambassador that the DPRK has two important uranium quarries. In one of these two places, the uranium content of the ore is 0.26 percent, while in the other it is 0.086 percent.” It is important to note that this report neither specifically identifies the Pyongsan area and significantly predates the start of mining activities at the Pyongsan mining complex. See: Balazs Szalontai and Sergey Radchenko, North Korea’s Efforts to Acquire Nuclear Technology and Nuclear Weapons: Evidence from Russian and Hungarian Archives (Washington, DC: Wilson Center, 2006), 43,; Jeffrey Lewis, “Recent Imagery Suggests Increased Uranium Production in North Korea, Probably for Expanding Nuclear Weapons Stockpile and Reactor Fuel,” 38 North, August 12, 2015,

    Uranium ore concentrates (yellowcake) can be any one of a number of chemical compounds including U3O8, UO2, Na2U2O7, (NH4) U2O7, or UO4. They also usually aren’t highly purified and will often contain leftover water, some impurities from the ore, and possibly impurities from the chemical processing. So 80 percent U3O8 is a reasonable average estimate for yellowcake. Author interview data.

  5. Kim, I Saw the Truth About the North Korean Nuclear, 9-21; “Visit by IAEA Director General Hans Blix to DPRK, May 11-16, 1992,” YouTube video, 12:54, December 6, 2017,
  6. Takashi Kawada, “North Korea Defector Confirms Plutonium Extraction in 1988,” Yomiuri Shimbun, May 20, 1994; “Further on Defector’s Remarks,” Yonhap, May 20, 1994; “Atomic Power Industrial Base Constructed Independently in Our Country,” KCTV, April 12, 1992.
  7. “Nuclear explained,” EIA; “Yellowcake,” NRC.