Cheonmasan Uranium Milling Facility and Suspected Uranium Enrichment Facility

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Last Updated: September 30, 2011
Other Name: 천마우라늄제련시설 및 의혹우라늄농축시설; Mt. Cheonma Uranium Milling Facility; Cheonmasan Power Plant; Mt. Cheonma Power Plant (천마산발전소)
Location: Daegwan-gun (대관군), North Pyeongan Province (평안북도), North Korea. Note: The facility is located underneath Mt. Cheonma that rises 1,116 meters above sea level. It is 40km to the southwest of Daegwan-eup, Daegwan-gun, and 30km to the northwest of Geumchang-ri. No one reportedly lives within 10km of the facility. [1]
Subordinate To: Probably the 5th Machine Industry Bureau (5기계공업총국), Korean Workers Party (조선노동당)
Size: About 10 rooms; approximately 535 workers, including about 100 management personnel, about 35 technicians, and about 400 political prisoners assigned to dangerous and physically taxing duties. About 16 technicians work in the underground operations.
Facility Status: Unknown

Cheonmasan is regarded as a uranium milling facility that is possibly also a site for uranium enrichment. Most of the information regarding this facility is based on the testimony of North Korean defector Lee Choon Seon, a former senior military official of the Korean People’s Army who defected to China in 1999 and was captured by the Chinese authorities. [2] His testimony for the first time publicized the existence of this underground facility. According to Lee, although known as the "Cheonmasan Power Plant," the facility is actually an underground uranium milling plant that produces yellowcake. [3] Additionally, this facility reportedly vents its exhaust fumes at the Geumchang-ri Underground Facility, which was suspected of clandestine nuclear-related activities but later was shown to be a series of empty and unfinished underground tunnels upon site inspection in 1999 and again in 2000.

According to Lee, North Korea initially planned to build a "nuclear production base (핵생산기지)" in the Mt. Cheonma area in 1983. Tunnel excavation began in 1983, and full-scale construction of the facility began in 1984. Lee stated that the Second Division under the Air Force Construction Bureau (공군건설부) of the Ministry of the People's Armed Forces was in charge of the construction. [Note: This contradicts other reports that claim the Third Engineer Bureau of the Nuclear Development Unit (핵개발부대3공병국) builds all underground nuclear facilities. [4] The stated purpose for the construction project was for a power plant and the needed underground waterway passing through Mt. Cheonma. However, the tunnels were actually to house a nuclear material production site. The tunnel construction was completed at the end of 1986, and equipment installation began in early 1987. The facility began to produce yellow cake at the end of 1989. [5]

According to Lee, uranium ore from mines in Seongcheon-gun (성천군) in South Pyeongan Province and Seoheung-gun (서흥군) in North Hwanghae Province is milled here. [6] However, there are no known reports of uranium mines in those areas. It is possible Lee was confusing them with uranium mines in Seoncheon-gun, South Pyeongan Province and in Pyeongsan-gun, North Hwanghae Province.

[Note: The pronunciation of "Seongcheon-gun" and "Seoncheon-gun" are similar, and they are about 20-40km apart in the same province. Seoheung-gun is adjacent to Pyeongsan-gun in North Hwanghae Province, and the mine could be in the mountain range that separates the two counties (gun or 군). Lee could have been referring to what is known as the Pyeongsan Uranium Mine.]

A regiment in the Transport Bureau under the Ministry of the People's Armed Forces apparently delivers uranium ore to the facility in Soviet-made trucks.

The facility has three steel security gates between the entrance and the production site. Inside the facility, there are about 10 rooms that are found about 600m to the right from the third security gate. The size and function of each room are as follows: [7]

  • Work Room (업무실): A dressing room where technicians and workers change into protective gear. This room is also used as a lounge.
  • Ore Room No. 1 (1호광석장): This room contains equipment and tanks for the "separation" or concentration of uranium ore. This room is about 50m x 60m.
  • Ore Room No. 2 (2호광석장): This room contains equipment to further process the output from Ore Room No. 1. This room also contains tanks and is about the same size as Ore Room No. 1.
  • Drying Room (건조실): This room is used to "dry" the output from Ore Room No. 2. This room is about 20m x 20m with a 20m-high ceiling.
  • Smelting Rooms No. One-Four (1/ 2/ 3/ 4 호 용융실): These rooms house equipment for smelting and are about 20m x 20m with 20m-high ceilings. The walls in these rooms are covered with 20-mm thick aluminum plates.
  • Packaging Room (포장실): This room is used to pack the refined uranium in airtight containers. This room is about 20m x 20m with a 4m-high ceiling. The walls in this room are also covered with 20-mm thick aluminum plates.
  • Output Storage Room (제품창고): This room is used to store the containers of refined uranium. This room is about 30m x 20m with a 4m-high ceiling.

About 100 meters from the Output Storage Room is another tunnel off to the right. At about 20 meters into the tunnel is an underground nuclear waste disposal area (핵폐기물처분장) of about 100m x 50m in size, and about 5m high that is covered with 5-mm thick aluminum plates. There are also a helicopter pad outside the facility and two check points to control access to the site. [8]

This facility has a director and three deputy directors responsible for administration, general affairs, and technology, as well as a general technological director. All of these positions are staffed by Korean People’s Army personnel. The general technological director supervises all technicians and the following seven divisions at the facility: [9]

  • Production Division (생산과): Production of nuclear material
  • Technology Division (기술과): Technical appraisal of ore and analysis of content
  • Planning Division (계획과): Establishment of production plans and implementation of production directives
  • Labor Division (노무과): Allocation of duties among technicians and workers
  • Labor Safety Division (노동안전과): Supervision of personnel and facility safety
  • Equipment and Material Division (기자재과): Purchase, repair, and maintenance of production equipment and materials
  • General Affairs Division (서무과): Administrative matters for employees and their families

Most of the active duty military personnel at the facility are over 40 years of age with families, and they do not wear military uniforms. Workers’ families live about 30km away in a group housing area, separated from the public.

In October 2002, North Korea admitted that it possesses a program to enrich uranium, [10] and this facility was named by the Americans as a potential site for the uranium enrichment program. In 2010, North Korea revealed for the first time that it had a uranium enrichment program at Yongbyon to American physicist Sigfried Hecker. [11]

Sources:
[1] “북한 핵물질 생산기지는 평북 대관군 천마산 지하에 있다: 탈북 인민군 장성의 충격증언 [Nuclear Facility is Underneath Mt. Cheonma: North Korean Defector’s Shocking Testimony],” Shindonga (Donga Ilbo’s Magazine), 1 August 2001, http://shindonga.donga.com.
[2] Lee Choon Seon, a former senior military official in the North Korean People’s Army, was interrogated while in the custody of the Chinese authorities. Before he could be brought to South Korea, he was repatriated back to North Korea where, according to Shindonga, he was probably executed. The original Chinese interrogation report was obtained by Shindonga and subsequently translated into Korean; “북한 핵물질 생산기지는 평북 대관군 천마산 지하에 있다: 탈북 인민군 장성의 충격증언 [Nuclear Facility is Underneath Mt. Cheonma: North Korean Defector’s Shocking Testimony],” Shindonga (Donga Ilbo’s Magazine), 1 August 2001, http://shindonga.donga.com.
[3] David Albright and Holly Higgins, “North Korea: It’s Taking Too Long,” Bulletin of the Atomic Scientists, January 2002, Vol. 58 No. 1, pp. 56-61.
[4] “Bureau of Engineers,” Federation of American Scientists, 22 November 1998, www.fas.org.
[5] “북한 핵물질 생산기지는 평북 대관군 천마산 지하에 있다: 탈북 인민군 장성의 충격증언 [Nuclear Facility is Underneath Mt. Cheonma: North Korean Defector’s Shocking Testimony],” Shindonga (Donga Ilbo’s Magazine), 1 August 2001, http://shindonga.donga.com.
[6]“북한 핵물질 생산기지는 평북 대관군 천마산 지하에 있다: 탈북 인민군 장성의 충격증언 [Nuclear Facility is Underneath Mt. Cheonma: North Korean Defector’s Shocking Testimony],” Shindonga (Donga Ilbo’s Magazine), 1 August 2001, http://shindonga.donga.com.
[7] “북한 핵물질 생산기지는 평북 대관군 천마산 지하에 있다: 탈북 인민군 장성의 충격증언 [Nuclear Facility is Underneath Mt. Cheonma: North Korean Defector’s Shocking Testimony],” Shindonga (Donga Ilbo’s Magazine), 1 August 2001, http://shindonga.donga.com.
[8] “북한 핵물질 생산기지는 평북 대관군 천마산 지하에 있다: 탈북 인민군 장성의 충격증언 [Nuclear Facility is Underneath Mt. Cheonma: North Korean Defector’s Shocking Testimony],” Shindonga (Donga Ilbo’s Magazine), 1 August 2001, http://shindonga.donga.com.
[9] “북한 핵물질 생산기지는 평북 대관군 천마산 지하에 있다: 탈북 인민군 장성의 충격증언 [Nuclear Facility is Underneath Mt. Cheonma: North Korean Defector’s Shocking Testimony],” Shindonga (Donga Ilbo’s Magazine), 1 August 2001, http://shindonga.donga.com.
[10] Press Statement, Richard Boucher, Spokesman, "North Korean Nuclear Program," U.S. Department of State, 16 October 2002, www.state.gov; David E. Sanger, "North Korea Says It Has a Program on Nuclear Arms," New York Times, p. A1, 17 October 2002, www.nytimes.com.
[11] Siegfried S. Hecker, "A Return Trip to North Korea's Yongbyon Nuclear Complex," Center for International Security and Cooperation, Stanford University, 20 November 2010, http://iis-db.stanford.edu.

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