North Korea's nuclear facilities

Nuclear Monitor Issue: 

(January 17, 2003) With the North Korean nuclear crisis high on the agenda for the international media, this article looks at the country's nuclear installations in order to provide a background to the crisis.

(581.5481) WISE Amsterdam - Nuclear technology has a long history in North Korea. According to one source, it began back in 1947 when the USSR sent geologists to North Korea to conduct surveys for uranium deposits, and uranium was mined and sent to the USSR before the start of the Korean War in 1950 (1).

North Korea set up its own Atomic Energy Research Institute in December 1952, while the Korean War was still underway. Following the armistice of 27 July 1953 that ended the Korean War (which the South Korean president refused to sign), nuclear activities in North Korea continued, with help from the USSR.

IRT-2000 research reactor
Help from the Soviet Union included training North Korean nuclear scientists at Soviet institutes from 1956 onwards, and was formalized in a 1959 nuclear cooperation treaty between the two countries. This was followed by the supply of an IRT-2000 research reactor (also called IRT-2M), which was started in 1965.

The IRT-2M, located in North Korea's largest nuclear complex at Yongbyon, did not produce electricity, and initially used low-enriched uranium (10% enrichment). However, in 1974, North Korean specialists modified the reactor, increasing its power from 2 to 8 megawatts thermal, and switching to bomb-grade uranium of 80% enrichment (2).

1974 was a key year for the North Korean nuclear program. As well as the uprate of the research reactor, a new Atomic Energy Act was enacted. President Kim Il Sung also obtained help from China, in the form of training for North Korean nuclear scientists and engineers (3). This was followed by North Korea joining the International Atomic Energy Agency (IAEA) on 16 September 1974.

Isotope Production Laboratory
The next key installation to be built at the Yongbyon site was the Isotope Production Laboratory in 1975. North Korea later admitted that it had carried out small-scale reprocessing in this laboratory, separating 300 milligrams of plutonium from fuel that had been irradiated in the IRT-2000. While this was clearly far to little to make an atomic bomb, it demonstrated that North Korea had the technology to do so.

In 1978, the IRT-2000 was placed under IAEA safeguards inspections, which were supposed to prevent the irradiated fuel from the reactor being sent to the Isotope Production Laboratory for separation of plutonium.

5-megawatt gas-graphite reactor
In 1979 or 1980 (4), North Korea began constructing its first electricity-producing reactor, Yongbyon-1 (sometimes confusingly called Yongbyon-2). This is a gas-graphite reactor based on the design of UK's Calder Hall 50-megawatt reactors, for which design information was declassified in the 1950s (5). However, while its thermal power is around 30 megawatts, it only generates 5 megawatts of electricity - which raises a big question mark over recent claims (6) that the country needs this reactor's electricity since oil aid was stopped (7).

The reactor is the only operational electricity-generating nuclear reactor in North Korea. It went critical on 14 August 1984 according to one source, 4 or 14 August 1985 according to others, and began regular operations in 1986 (8). It uses natural uranium, which has two advantages for North Korea. Firstly, North Korea has its own uranium mines but - back in the 1980's - had no uranium enrichment facilities. The use of natural uranium therefore reduced the country's dependence on the Soviet Union in line with Kim Il-Sung's policy of Juche (national self-reliance).

Secondly - and more worryingly - reactors using natural-uranium fuel are more suitable for producing plutonium for weapons use. In addition, the magnesium cladding of the Magnox fuel used in the reactor (just as in the UK's Calder Hall) makes it easier to reprocess (9).


As the North Korean nuclear crisis continues, it is remarkable how many similarities exist with an earlier crisis that led up to the signing of the "Agreed Framework" in 1994.

Then, as now, the crisis followed U.S. allegations that North Korea was developing nuclear weapons. It led to a war of words, as the U.S. threatened to attack North Korea, while North Korea responded by threatening to turn the city of Seoul in South Korea into a "storm of fire".

However, after the intervention of former U.S. President Jimmy Carter, the rhetoric became calmer and two sides entered into talks. These talks did not always go well, and they were interrupted by the death of North Korea's president Kim Il Sung, who was subsequently declared to be the country's "eternal president".

The talks eventually resumed, with the North Koreans saying they would keep the promise of a nuclear freeze which Kim Il Sung had made in his last days. They ended with the "Agreed Framework" which was signed in Geneva, Switzerland on 21 October 1994.

This "replace-nuclear-with nuclear" agreement basically laid down that North Korea would give up its existing nuclear program in return for the construction of two Western-designed reactors. These reactors would be "more proliferation-resistant", but would still produce plutonium - in much larger quantities than North Korea's existing reactors. As the November 1999 report of the North Korea Advisory Group to the U.S. Congress pointed out: "Such plutonium, while not weapons-grade, can be used to produce nuclear weapons and does not present an overwhelming barrier to those pursuing a dedicated nuclear weapons program."

This gave rise to a crisis in the early 1990s, following reports that the reactor was shut down in 1989 for about 70 days. The U.S. claimed that the shutdown enabled refueling and reprocessing of the irradiated fuel to extract plutonium for nuclear weapons. North Korea only admitted removing damaged fuel rods and extracting about 90 grams of plutonium (10).

The crisis was resolved by the 1994 "Agreed Framework" (11), under which North Korea agreed to stop the reactor and halt construction of two other gas-graphite reactors. In return, an international organization, the Korean Peninsula Energy Development Organization (KEDO) was set up to build two light-water reactors in Kumho, and supply North Korea with fuel oil until the reactors are operational.

Recently, North Korea said it was withdrawing from the Non-Proliferation Treaty so that it can re-start the reactor to "protect its people from the winter" (12). However, the reactor's 5-megawatt output - less than a typical small wind farm - would only supply a tiny fraction of the country's electricity needs.

50-megawatt gas-graphite reactor
Given the tiny output of the 5-megawatt gas-graphite reactor, it is not surprising that North Korea began building larger reactors. First of these was another reactor at Yongbyon intended to generate 50 megawatts of electricity - the same as the UK's Calder Hall and Chapelcross reactors. Construction reportedly began in 1984 or 1985 though US intelligence did not detect it until 1989 (13). It is not clear if the technology was copied from the UK's Calder Hall or France's G-2 gas-graphite reactor (14). Construction was frozen under the 1994 "agreed framework".

200-megawatt gas-graphite reactor
In 1989, North Korea also started to build a 200-megawatt reactor at Taechon, reportedly based on the French G-2 gas-graphite reactor (15). Again, construction of the reactor was halted under the 1994 "Agreed Framework".

Two 1000-megawatt reactors
In return for stopping the 5-megawatt reactor and halting construction of the 50 and 200-megawatt reactors, North Korea was to be supplied with two 1000-megawatt "light-water reactors" under the 1994 "Agreed Framework". The site chosen was Kumho, which according to one source was originally selected in 1990 for construction of four Russian VVER-440 reactors. When the Soviet Union collapsed in 1991, the North Korean regime first wanted to design and build its own reactors on the site, but in 1994 agreed that KEDO would build two Western-designed light-water reactors (i.e. PWR or BWR) on the site (16).

North Korea has repeatedly complained of delays in the construction - the reactors were to be completed in 2003, but the first concrete was not poured until 2002. The delays mean that even before the current crisis, delivery of key nuclear components was not expected until 2005. This probably explains why there seems to be no hurry to stop the Kumho project (17).

Reprocessing facilities
North Korea first began separating plutonium on an experimental scale in the Isotope Production Laboratory at Yongbyon, which was built around 1965. This laboratory has never been under IAEA safeguards, even though North Korea admitted in 1992 that around 300mg of plutonium had been separated in the laboratory in 1975 (18).

The real concern, however, is the "Radiochemistry Laboratory". North Korea said that this building, whose construction was never completed, was intended for "training specialists in the separation of plutonium, and for handling nuclear waste". However, this "six-story building, approximately 180m in length, 20m in width, and about the size of two football fields" is clearly too large to be just a training facility, and the IAEA concluded after a 1992 inspection that it was a reprocessing plant. Construction was halted under the 1994 "Agreed Framework" when it was placed under IAEA safeguards (19).

Uranium program
Still, even with the reprocessing facilities and reactors "frozen", North Korea had another option for building nuclear weapons: mining its own indigenous uranium reserves and enriching the uranium to bomb-grade. The recent crisis was prompted by allegations that North Korea had started a uranium-based weapons program (20). Dr. Abdul Qadir Khan, who started Pakistan's nuclear weapons program based on centrifuge uranium enrichment technology from Urenco Netherlands where he once worked (21), was alleged to have supplied the same technology to North Korea (22). Khan denied these allegations (23).

However, it is worth remembering that a November 1999 report to the US Congress (24) had already warned of this possibility. Under "Uranium enrichment", the report stated: "Among the many mysteries surrounding North Korea's nuclear program are its extensive uranium mining and milling activities. North Korea's interest in uranium dates back several decades, and North Korea is known to have attempted to acquire uranium enrichment equipment" (25).

The report continued: "The capability to enrich uranium to weapons-grade would provide North Korea with a second path to nuclear weapons and, if realized, could add a dangerous new dimension to Pyongyang's nuclear weapons development activities".

Nuclear waste
Finally, it is perhaps worth remembering one of the sticking points that the 1994 "Agreed Framework" failed to resolve: the nuclear waste issue. In 1993, the IAEA demanded to inspect two suspected nuclear waste sites in the Yongbyon complex (an old nuclear waste site and the so-called "Building 500"). North Korea replied by deploying tanks around the sites and has consistently refused to allow IAEA inspectors to visit these sites. Under the terms of the "Agreed Framework," North Korea is required to accept IAEA inspections of these sites when a significant portion of the Kumho project is completed, but before delivery of key nuclear components (26).

The question remains as to whether the current crisis will deal with this outstanding waste issue. It underlines the nuclear industry's unsolved problem with nuclear waste: the technology to reprocess it to produce plutonium for bombs is tried and tested, but no known technology can stop it from remaining lethally radioactive for thousands of years.

The best solution for North Korea is not to finish the Kumho reactors, which would generate even larger quantities of waste; nor is it to re-start old reactors which are better at making plutonium than electricity. As a WISE News Communique article concluded in 2001, the most effective strategy is an integrated coordinated effort to rebuild existing energy infrastructure, develop alternative energy resources, increase energy efficiency and meet humanitarian needs (27).


  2. (However, other sources say the reactor's power was increased to 4 megawatts thermal in 1974 and 8 megawatts thermal in 1977.)
  4. 1979 according to or 1980 according to
  5. WISE News Communique 411.4072, "DPRK: Eurochemic and Calder Hall clones"
  6. For example, Russian defense minister Sergei Ivanov, quoted by the North Korean state news agency KCNA on 10 January 2003
  7. WISE/NIRS Nuclear Monitor 577.5460, "North Korea: oil aid stopped"
  9. WISE News Communique 411.4072, "DPRK: Eurochemic and Calder Hall clones"
  12. North Korean government site, 14 January 2003
  17. WISE/NIRS Nuclear Monitor 577.5460, "North Korea: oil aid stopped"
  20. WISE/NIRS Nuclear Monitor 575, "In brief"
  21. WISE News Communique 499/500.4932, "Uranium enrichment: No capacity growth in 20 years"
  22. The Tribune (Chandigarh, India), 9 January 2003
  23., 9 January 2003
  24. Report of the North Korea Advisory Group (
  25. The report quotes Jane's Intelligence Review, 1 August 1999, p21 as a source for the statement that North Korea had attempted to acquire uranium enrichment equipment.
  26. and
  27. WISE News Communique 545.5260, "What is the best solution/future for North Korea?"

Contact: WISE Amsterdam