In the early 1990s, there was growing international concern that North Korea was seeking to produce nuclear weapons. In 1991, despite North Korea's repeated denials of a nuclear weapons program, United States policy experts generally agreed that P'yongyang was engaged in a nuclear weapons program. The debate has centered on when, rather than whether, North Korea will have a nuclear capability. Estimates range from 1993 to several years later.

North Korean nuclear-related activities began in 1955, when representatives of the Academy of Sciences participated in an East European conference on the peaceful uses of nuclear energy. In 1956 North Korea signed two agreements with the Soviet Union covering joint nuclear research. In 1959 additional agreements on the peaceful uses of nuclear energy were signed with the Soviet Union and China. The 1959 Soviet agreement apparently included setting up a nuclear research facility under the Academy of Sciences near Yngbyn and developing a nuclear-related curriculum at Kim Il Sung University. Chinese and Soviet assistance with training of nuclear scientists and technicians, although not continuous, is the major source of North Korean nuclear expertise. In the 1980s, P'yongyang had a rather eclectic if low-key web of nuclear connections that included Cuba, Czechoslovakia, and the former Democratic Republic of Germany (East Germany). North Korea also is believed to have nuclearrelated connections with Egypt, Iran, Libya, Romania, and Syria.

The Yngbyn center was established in early 1962 at Yong Dong on the Kuryong River, approximately 100 kilometers north of Pyngyang and southwest of the city of Yngbyn. Construction began in 1965 on a Soviet-supplied two-kilowatt nuclear research reactor (IRT2000) that is believed to have become operational in 1967. The reactor was brought under International Atomic Energy Agency (IAEA--see Glossary) controls in July 1977 and was modified over time to increase its power to approximately eight kilowatts.

During the mid-1970s, North Korea began expanding its nuclear infrastructure. In 1980 construction began on an indigenously designed, graphite-moderated, gas-cooled thirty-megawatt reactor, which probably is primarily for plutonium production. The use of graphite and natural uranium allowed North Korea to avoid foreign involvement and constraints. The reactor apparently became operational in 1987, but its existence has not been formally acknowledged by North Korea.

According to many sources, United States satellites detected additional nuclear-related facilities under construction in the Yngbyn area during 1989. When completed, the facilities will give North Korea the complete nuclear fuel cycle needed for weapons production. These facilities consist of a high explosives testing site, a reprocessing facility, a third reactor in the fifty-megawatt to 200-megawatt range, and associated support facilities. According to sources, construction began on a third reactor in 1984-85 and on a reprocessing facility in 1988-89 the former is s8e1 scheduled to be operational by the end of 1992 but was not on-line as of mid-1993, and the latter perhaps a little later. Neither the thirty-megawatt reactor nor the third reactor are said to be connected to a power grid for power generation. In 1990 these reports were substantiated by satellite photography read by Japanese scientists. According to South Korean sources, if all the facilities come online, North Korea will be capable of producing enough plutonium for two to four twenty-kiloton nuclear weapons a year. The facilities, however, are contaminated and not operational.

P'yongyang signed the Nuclear Nonproliferation Treaty in July 1985 but delayed signing the IAEA Full Scope Safeguards Agreement. The IAEA granted an eighteen-month extension of the usual eighteen months necessary to administer and sign such agreements. North Korea agreed in principle to the agreement in July 1991, but delayed signing until January 30, 1992 implementation was not to take place until after ratification of the agreement. In a series of agreements with South Korea at the end of 1991, North Korea agreed to set up a Joint Nuclear Control Committee (JNCC) to ensure that there are no nuclear weapons in either country. The committee will develop procedures for additional inspections to encompass facilities normally outside IAEA jurisdiction, such as military facilities.

Data as of June 1993