South Korea has the raw materials and equipment to produce a nuclear weapon. However, it has not opted to make one.[1] South Korea has continued on a stated policy of non-proliferation of nuclear weapons since 2004 and has adopted a policy to maintain a nuclear-free Korean Peninsula. By contrast, North Korea has and is developing additional nuclear weapons.
In August 2004, South Korea revealed the extent of its highly secretive and sensitive nuclear research programs to the International Atomic Energy Agency (IAEA), including some experiments which were conducted without the obligatory reporting to the IAEA called for by South Korea's safeguards agreement.[2] The IAEA Secretariat reported the failure to report to IAEA Board of Governors.[3] However, the IAEA Board of Governors decided to not make a formal finding of noncompliance.[4]
When the United States notified the South Korean administration of its plan to withdraw USFK in July 1970, South Korea first considered the possibility of an independent nuclear program. Under the direction of South Korea's Weapons Exploitation Committee, the country attempted to obtain plutonium reprocessing facilities following the pullout of the 26,000 American soldiers of the 7th Infantry Division in 1971.[5] After South Vietnam had fallen in April 1975, then South Korean president Park Chung-hee first mentioned its nuclear weapons aspiration during the press conference on 12 June 1975.[6] However, under pressure from the United States, France eventually decided not to deliver a reprocessing facility to South Korea in 1975.[5] South Korea's nuclear weapons research program effectively ended on April 23, 1975, with its ratification of the Nuclear Non-Proliferation Treaty.[5]
In 1982, scientists at the Korean Atomic Energy Research Institute performed an experiment in which they extracted several milligrams of plutonium. Although plutonium has uses other than the manufacture of weapons, the United States later insisted that South Korea not attempt to reprocess plutonium in any way. In exchange, the US agreed to transfer reactor technology and give financial assistance to South Korea's nuclear energy program. It was revealed in 2004 that some South Korean scientists continued some studies; for example, in 1983 and 1984 Korea Atomic Energy Research Institute was conducting chemical experiments related to the handling of spent fuel that crossed the reprocessing boundary.[7]
Later, in an experiment at the same facility in 2000, scientists enriched 200 milligrams of uranium to near-weapons grade (up to 77 percent) using laser enrichment.[7][8] The South Korean government claimed that this research was conducted without its knowledge.[9] While uranium enriched to 77 percent is usually not considered weapons-grade, it could theoretically be used to construct a nuclear weapon.[10][11] Highly enriched uranium with a purity of 20% or more is usable in a weapon, but this route is less desirable as far more material is required to obtain critical mass.[12]
Following Seoul's disclosure of the above incidents, the IAEA launched a full investigation into South Korea's nuclear activities. In a report issued on November 11, 2004, the IAEA described the South Korean government's failure to report its nuclear activities a matter of "serious concern", but accepted that these experiments never produced more than very small amounts of weaponizeable fissile material. The Board of Governors decided to not make a formal finding of noncompliance, and the matter was not referred to the Security Council.[4]