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Yongbyon 5MWe Reactor

Last Modified: March 19, 2014
Other Name: 5MWe실험용원자로; Experimental Nuclear Power Station-1; Experimental Nuclear Power Plant No. 1(시험원자력발전소 1호기); Yongbyon No. 1 Machine (영변1호기); the Second Reactor, Reactor No. 2 (제2호원자로); February Enterprise (2월기업소); Reactor 1; 5MWe pilot plant; Calder Hall Clone
Location: Bungang-jigu (분강지구), Yongbyon-gun (영변군), Pyeonganbuk-do (평안북도), North Korea
Subordinate To: Nuclear Physics Research Institute (핵물리연구소), Yongbyon Nuclear Research Center (영변원자력연구센터), General Department of Atomic Energy (원자력총국), Cabinet (내각)
Size: 5MWe, about 20-25MWth
Facility Status: Under Construction for Restart


Graphite-moderated and gas-cooled, the 5MWe reactor has a thermal power range of 20-25MW. Modeled after the U.K.’s Calder Hall reactor, construction of the reactor began in 1979 and it was operational by 1986.[1] There were several practical advantages for North Korea to select this type of reactor design: it uses natural uranium for its fuel, which is abundant in North Korea; it has a carbon-dioxide gas cooling system requiring no heavy water; and it uses graphite, which is also available in North Korea, as a moderator.

Although North Korea told the International Atomic Energy Agency (IAEA) that the reactor would be used for electricity generation, a possible military purpose was suspected as the reactor’s design can easily produce weapon-grade plutonium.[2] These suspicions were confirmed when North Korea announced it had built nuclear weapons in 2005 and conducted its first nuclear test in 2006.[3]

The reactor is believed to have been shut-down in 1989, 1990, and 1991 as indicated by U.S. satellite imagery.[4] Only the 1989 shutdown is believed to have been long enough to enable unloading of all or much of the fuel in the reactor core. North Korea later reported to the IAEA that it reprocessed about 90 grams of plutonium from damaged spent fuel rods that were removed from the reactor in 1989, but made no reference to the reactor being shut down in 1990 or 1991.[5]

The IAEA inspection of the 5MWe reactor and other nuclear facilities in the Yongbyon Nuclear Research Center commenced following the ratification of its safeguards agreement in April 1992.[6] During these inspections, the IAEA discovered discrepancies in North Korea's initial declaration, which led the IAEA to request special ad hoc inspections. North Korea balked at this request and announced its intention to withdraw from the Treaty on the Non-Proliferation of Nuclear Weapons (NPT).[7] However, following talks with Washington, Pyongyang suspended its withdrawal from the NPT in June 1993, just days before it would have gone into effect.[8]

In May and June of 1994, North Korean technicians, without the supervision of IAEA inspectors, once again discharged up to 60 percent of the reactor's spent fuel rods and placed them in a cooling pond.[9] This action nearly led to a military confrontation with the United States, before former President Jimmy Carter's trip to Pyongyang defused the crisis. Carter's trip encouraged North Korean leader Kim Il Sung to continue negotiations on the Agreed Framework, which concluded successfully in October 1994. Under the terms of the agreement, the spent fuel rods unloaded in 1994 were canned and stored in Yongbyon until they could be shipped to a third country.[10]

In October 2002, the United States confronted North Korea about a suspected uranium enrichment program, leading to the breakdown of the Agreed Framework.[11] Subsequently, Pyongyang indicated in December that it intended to restart the 5MWe reactor and withdraw from the NPT.[12] U.S. officials confirmed the reactor was restarted in February 2003.[13] North Korea indicated that 8,000 spent fuel rods that were in storage since 1994 were processed, and that another 8,000 spent fuel rods were discharged and processed in 2005.[14]

As part of the 2007 round of Six-Party Talks, agreements were made to disable the reactor and remove the fuel. In 2008, the cooling tower was demolished as part of the agreement. In April 2009, North Korea threatened to restore the reactor in response to the U.N. Security Council's condemnation of the North Korean missile test earlier in the month. However, satellite imagery from 10 August 2009 indicated that no construction had begun on either the reactor site or the cooling tower.[15] In a November 2010 visit by U.S. experts to the facility, the reactor still appeared to be inactive. They were told that it is in stand-by status with regular maintenance.[16]

On 2 April 2013, North Korea announced it will restart the Yongbyon 5MWe Reactor for plutonium production as part of a nationwide restart of all its nuclear facilities.[17] Commercial satellite imagery of the site from late March 2013 shows that work has begun to connect the reactor’s secondary cooling system to the pump house of the adjacent experimental light water reactor.[18]  This is an essential step to restoring the reactor to an operational status, and suggests that it may indeed be restarted. By September 2013, satellite imagery indicated that North Korea restarted the 5 MWe reactor, presumably for the production of weapons grade plutonium.[19]

Sources:
[1] International Atomic Energy Agency, “IAEA and DPRK: Fact Sheet on DPRK Nuclear Safeguards,” www.iaea.org.
[2] David Albright and Kevin O'Neill, eds., Solving the North Korean Nuclear Puzzle (Washington, D.C.: Institute For Science and International Security, 2000).
[3] “DPRK FM on Its Stand to Suspend Its Participation in Six-party Talks for Indefinite Period,” Korean Central News Agency, 11 February 2005, www.kcna.co.jp; "DPRK Successfully Conducts Underground Nuclear Test," Korean Central News Agency, 10 October 2006, www.kcna.co.jp; "Magnitude 4.3 — North Korea," USGS, 9 October 2006, http://earthquake.usgs.gov.
[4] David Albright and Kevin O'Neill, eds., Solving the North Korean Nuclear Puzzle (Washington, D.C.: Institute For Science and International Security, 2000).
[5] David Albright and Kevin O'Neill, eds., Solving the North Korean Nuclear Puzzle (Washington, D.C.: Institute For Science and International Security, 2000).
[6] International Atomic Energy Agency, “Agreement of 30 January 1992 between the Government of the Democratic People's Republic of Korea and the International Atomic Energy Agency for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons,” Information Circular, INFCIRC/403, May 1992, www.iaea.org.
[7] International Atomic Energy Agency, “IAEA and DPRK: Fact Sheet on DPRK Nuclear Safeguards,” www.iaea.org; "Letter from Kim Yong-nam, DPRK Minister of Foreign Affairs," Reuters, 12 March 1993.
[8] “China welcomes North Korea's NPT decision,” Agence France Presse, 12 June 1993, via: www.lexisnexis.com.
[9] "북한 핵연료봉 60% 빼내 [North Korea Discharged 60% of Nuclear Fuel Rods]", Yonhap News Agency, 31 May 1994, www.yonhap news.co.kr.
[10] “Agreed Framework between the United States of America and the Democratic People's Republic of Korea,” 21 October 1994, via: www.nti.org.
[11] Richard Boucher, "Press Statement: North Korean Nuclear Program," U.S. Department of State, 16 October 2002, www.state.gov; James A. Kelly, "U.S.-East Asia Policy: Three Aspects," Remarks at the Woodrow Wilson Center, Washington, DC, 11 December 2002, www.state.gov.
[12] “Statement of DPRK Government on its withdrawal from NPT,” Korean Central News Agency, 11 January 2003, www.kcna.co.jp.
[13] "Chronology of U.S.-North Korean Nuclear and Missile Diplomacy," Arms Control Association, www.armscontrol.org.
[14] “KCNA Report on Nuclear Activities in DPRK,” Korean Central News Agency, 3 October 2003, www.kcna.co.jp; “Spent Fuel Rods Unloaded from Pilot Nuclear Plant,” Korean Central News Agency, 11 May 2005, www.kcna.co.jp; “DPRK Completes Reprocessing of Spent Fuel Rods,” Korean Central News Agency, 3 November 2009, www.kcna.co.jp.
[15] "No Reconstruction at the Yongbyon Reactor Site", ISIS Imagery Brief, 4 September 2009, http://isis-online.org.
[16] Siegfried 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.
[17] “DPRK to Adjust Uses of Existing Nuclear Facilities,” KCNA, 2 April 2013, www.kcna.co.jp.
[18] Nick Hansen and Jeffrey Lewis, “Satellite Images Show New Construction at North Korea’s Plutonium Production Reactor; Rapid Restart?” 38 North, 3 April 2013, www.38north.org.
[19] Nick Hansen and Jeffrey Lewis, “North Korea Restarting Its 5 MW Reactor,” 38 North, 11 September 2013, www.38north.org; Nick Hansen, “More Evidence That North Korea Has Restarted Its 5 MWe Reactor,” 38 North, 2 October 2013, www.38north.org.

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This material is produced independently for NTI by the James Martin Center for Nonproliferation Studies at the Monterey Institute of International Studies and does not necessarily reflect the opinions of and has not been independently verified by NTI or its directors, officers, employees, or agents.

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