In 1981, South Korean engineers produced five test fuel rods using depleted uranium. The fuel rods were placed in a research reactor and irradiated between July and December 1981. The spent fuel rods were removed and scientists conducted experiments in hot-cells to extract 0.3 grams of plutonium.[2] The South Korean Ministry of Science and Technology (MOST) claimed that this experiment was conducted by "a small group of scientists to analyze the chemical characteristics of plutonium."[3] These experiments were not revealed to the public until the summer of 2004, after South Korea had ratified the Additional Protocol. Under this modified safeguards agreement with the International Atomic Energy Agency (IAEA), South Korean nuclear facilities were subject to more detailed inspections.[4] In the summer of 2004, South Korea also reported that its scientists had conducted laser isotope separation experiments to enrich about 0.2 grams of uranium. Both the plutonium extraction and uranium enrichment experiments were in violation of Seoul's safeguards commitments, but the government cooperated with the IAEA to account for these violations and to ensure there were no future violations.[5] During the June 2008 IAEA Board of Governors meeting, a "broader conclusion" was drawn that all nuclear material in South Korea had been placed under safeguards and remained in peaceful nuclear activities.[6]

In November 1991, President Roh Tae Woo (노태우) declared that South Korea would not "manufacture, possess, store, deploy, or use nuclear weapons."[7] Two months later, North Korea and South Korea signed the Joint Declaration on the Denuclearization of the Korean Peninsula. In this agreement, Seoul and Pyongyang agreed not "to test, manufacture, produce, receive, possess, store, deploy or use nuclear weapons," and not to "possess nuclear reprocessing and uranium enrichment facilities." However, both sides failed to implement the agreement's provisions relating to a bilateral inspection regime. Although North Korea has violated the Joint Declaration, particularly in light of its two nuclear weapons tests (in 2006 and 2009), South Korea has never officially renounced its obligations under the declaration and has called on the North to abide by the agreement. Seoul has been a participant in the Six-Party Talks, aimed at ending the nuclear crisis on the Korean Peninsula, since their inception in 2003.

South Korea has a total of 23 nuclear power reactors in operation—ranking fifth in the world in number of reactors. As of 2012, nuclear energy provides approximately34.64 percent of its total electricity.[8] Korea plans to complete 18 new nuclear power plants by 2030 which will account for 60% of the country's electricity generation. Also in December 2010, Ministry of Knowledge Economy announced that 14 new nuclear reactors will be completed by 2024.[9] A joint research project by the Korea Atomic Energy Research Institute (KAERI) and National Fusion Research Institute (NFRI) is currently underway to develop the 4^th generation of nuclear power plants (Gen IV) which will incorporate Sodium-cooled Fast Reactor (SFR) and Very High Temperature gas-cooled Reactor (VHTR). The goal is to commercialize these technologies by 2030.[10] In January 2010, the Ministry of Knowledge Economy has announced that it plans to export 80 nuclear power reactors by 2030 which is worth $400 billion. Thus far, a US$20 billion contract to construct four reactors in the United Arab Emirates, and a $173 million contract to construct a nuclear research reactor in Jordan.[11] South Korea’s nuclear industry has also shown keen interest in penetrating into Chinese market which holds significance since China has been known to transfer its nuclear technologies and equipment to Pakistan, which is not a member of the NPT.[12]

Despite South Korea's extensive nuclear energy infrastructure and technological base, South Korea does not possess any independent means of enrichment or reprocessing. While its legal validity remains ambiguous, South Korea is politically constrained by the 1992 Joint Declaration with North Korea and the 1974 bilateral pact on nuclear cooperation. However, South Korean officials have expressed a keen interest in establishing a closed nuclear fuel cycle toward its goal of overtaking 20 percent of the global nuclear reactor market.[13] Additionally, South Korea’s own reliance on nuclear power is projected to grow, and the problem of mounting spent nuclear fuel is a pressing one.[14] As a country that has one of the highest population density in the world, South Korea’s problem of spent nuclear fuel storage stem from both securing the physical space and the strong domestic opposition from the Koreans who do not want the interim storage site in their neighborhood. South Korean officials have been making strong arguments for the legitimacy of pyroprocessing, however, it is not supported by the U.S. government which views pyroprocessing as another form of reprocessing. With the expiration of U.S.-South Korea nuclear cooperation agreement approaching in 2014, the issue of pyroprocessing will be the main area of contention at the negotiation table.[15]

Sources:
[1] Ha Yeong-seon, 한반도의 핵무기와 세계질서 [Nuclear Weapons on the Korean Peninsula and World Order] (Seoul: Nanam, 1991).
[2] Daniel A. Pinkston, "South Korea's Nuclear Experiments," CNS Research Story, 9 November 2004, http://cns.miis.edu.
[3] Anthony Faiola and Dafna Linzer, "S. Korea Admits Extracting Plutonium," Washington Post, 10 September 2004, www.washingtonpost.com.
[4] Anthony Faiola and Dafna Linzer, "S. Korea Admits Extracting Plutonium," Washington Post, 10 September 2004, www.washingtonpost.com.
[5] Mohamed El-Baradei, "Introductory Statement to the Board of Governors," IAEA Website, 13 September 2004, www.iaea.org.
[6] "IAEA Confirms S. Korea's Nuclear Activity Peaceful," Yonhap, 3 June 2008, in www.lexisnexis.com.
[7] Roh Tae Woo, "President Roh Tae Woo's Declaration of Non-Nuclear Korean Peninsula Peace Initiatives," 8 November 1991, available at www.fas.org.
[8] International Atomic Energy Agency, “Korea, Republic of,” Power Reactor Information System Database, 19 June 2012, http://pris.iaea.org. "Nuclear Power in South Korea," World Nuclear Association, April 2012, http://world-nuclear.org.
[9] "Nuclear Power in South Korea," World Nuclear Association, April 2012, http://world-nuclear.org.
[10] “차세대 원자로 개발 [Developing Nuclear Reactors for Future],” Korea Atomic Energy Research Institute, June 2012, www.kaeri.re.kr.
[11] "Korean Consortium for Jordan's First Reactor," World Nuclear News, 7 December 2009, www.world-nuclear-news.org; "UAE Picks Korea as Nuclear Partner," World Nuclear News, 29 December 2009, www.world-nuclear-news.org.
[12] Fred McGoldrick, “Nuclear Nonproliferation,” in  The US-South Korea Alliance: Meeting New Security Challenges, ed. Scott Snyder (Boulder, CO: Lynne Rienner Publishers, Inc., 2012).
[13] Park Seong-won, Miles A. Pomper, and Lawrence Scheinman, “The Domestic and International Politics of Spent Nuclear Fuel in South Korea: Are We Approaching Meltdown?” Korea Economic Institute Academic Paper Series, March 2010, Volume 5, Number 3, p. 4.
[14] "Fuel Cycle Process Development Division," Korea Atomic Energy Research Institute, http://ehome.kaeri.re.kr.
[15] Park Seong-won, Miles A. Pomper, and Lawrence Scheinman, “The Domestic and International Politics of Spent Nuclear Fuel in South Korea: Are We Approaching Meltdown?” Korea Economic Institute Academic Paper Series, March 2010, Volume 5, Number 3, p. 4.