BACKGROUND

Under the 1953 Atoms for Peace Program initiated by President Dwight D. Eisenhower, the United States transferred research reactors and low enriched uranium (LEU) fuel (less than 20% U-235) for these reactors to foreign states. However, the LEU fuel technology used at that time soon encountered limits. In order to build more powerful reactors, HEU fuel soon became the standard used by the vast majority of research reactors. In the decade after the launch of the Atoms for Peace program, the United States, the Soviet Union, and other nuclear weapon states exported research reactors fueled with HEU to approximately 40 countries. In addition to research and test reactors, HEU was and continues to be used in other civilian technologies, including for naval and space propulsion, medical isotope production, and as fuel for commercial fast neutron reactors.

The 1974 "peaceful" nuclear test by India dramatically changed global views on exports of fissile materials and technologies. In 1975, the Nuclear Suppliers Group (NSG), a multinational body that sets guidelines for nuclear exports, including dual-use technologies and materials, was created. Since then, major nuclear exporting states have required the establishment of International Atomic Energy Agency (IAEA) full-scope safeguards for transfers of nuclear materials and technologies. The IAEA also established guidelines for the physical protection of civilian sites and material. Still, the level of protection has varied from country to country, and vulnerability of HEU remains a concern at many civilian sites that were not originally designed with security considerations in mind.

India's test also spurred both the United States and the Soviet Union to launch programs in the 1970s to mitigate the threat of possible misuse of HEU from civilian installations. These efforts received additional impetus during the early 2000s. At that time, the rise of the terrorist threat and the danger that HEU from the civilian sector could be used to construct an improvised nuclear device increased international concern regarding HEU security. Programs to accelerate the return of vulnerable civilian HEU worldwide and to promote the reduction and subsequent phase-out of HEU use in the civilian sector have become one of the mainstays of U.S. nonproliferation policy. They have also received widespread international acceptance and support.

EFFORTS TO CONVERT REACTORS TO LEU AND TO REMOVE HEU FROM SITES OF CONCERN

Both the United States and the Soviet Union launched efforts in the late 1970s to mitigate the threat of possible misuse of HEU from civilian installations. The primary focus of these efforts was on developing replacement fuels and converting HEU-fueled research reactors to use lower enriched uranium. Foreign reactors received the priority in these efforts.

U.S. Reduced Enrichment for Research and Test Reactors (RERTR) Program

In 1978, the United States initiated the Reduced Enrichment for Research and Test Reactors Program (RERTR). The program's original mission was to develop LEU fuel for foreign research and test reactors with power levels of more than 1 MW that the United States was supplying with HEU. These reactors received the primary attention because their cores contained several kilograms of HEU and required regular refueling. Additional missions to convert U.S. university reactors and to develop substitute LEU targets for medical isotope production were added in the 1980s. Other civilian reactors using HEU were subsequently added to the program. [1]

Several types of replacement LEU fuels have also been developed under RERTR. Uranium-silicide fuel developed in the 1980s has a uranium density sufficient to convert the vast majority of reactors. Uranium-molybdenum (U-Mo) fuels with very high uranium densities are currently under development and testing, and could potentially replace HEU fuel in the remaining reactors. Since RERTR's inception, many countries have joined the program and started their own efforts to convert reactors and isotope production to LEU. [2]

RERTR and other HEU minimization efforts have increased global awareness of the risks associated with the use of HEU for research and other civilian purposes. [3] Since the early 1980s, no new civilian research reactors with a power level of more than 1 MW that use HEU fuel have been built in Western countries, with the exception of Germany's FRM-II reactor. Seventeen new research reactors worldwide were built using LEU fuels.

Despite its achievements, the RERTR program has had some shortcomings. For example, it does not cover fast critical assemblies or propulsion reactors, some of which contain substantial amounts of HEU in their cores.[4] Moreover, U.S. federal funding for the program was very low for several decades, which negatively affected the pace of the development of replacement fuels. Fuel development and testing, in general, requires a long-term commitment. Additional funding would likely have led to more aggressive research and development in this area. The program also suffered some technical setbacks, including difficulties with the U-Mo dispersion fuel. As a consequence, LEU fuel availability and reactor conversion deadlines for reactors that require new fuels have been repeatedly extended. [5]

Global Threat Reduction Initiative (GTRI)

The slow progress of the RERTR program and international cooperation in this area in the late 1990s and early 2000s primarily could be attributed to the meager funding of these activities and government inattention. In 2004, the U.S. Department of Energy, in response to criticism about the slow pace of the nuclear and radioactive material cleanout, launched the Global Threat Reduction Initiative (GTRI). The GTRI Program subsumed LEU fuel development, reactor conversion, and HEU fuel repatriation activities worldwide, as well as a number of other initiatives addressing nuclear and radioactive material security.

The GTRI program includes the Reduced Enrichment for Research and Test Reactors (RERTR) Program, the Foreign Research Reactor Spent Nuclear Fuel (FRR SNF) Acceptance Program, the Russian Research Reactor Fuel Return (RRRFR) Program, and others. GTRI efforts also include the Emerging Threats and Gap Material Program, which is designed to address vulnerable, high-risk nuclear and radiological materials throughout the world that are not currently being addressed under other existing programs. [6]

The GTRI efforts have become a U.S. national security priority, receiving high-level endorsement and a consistent stream of funding. GTRI has targeted 200 reactors in the United States and around the world for conversion or shutdown prior to 2020. To date, over 72 facilities have been verified as converted or shut down. All U.S. reactors that could be converted with existing qualified LEU fuel have already been converted or verified as shut down. GTRI is currently working on the development and qualification of LEU fuel that would enable the conversion of the remaining six U.S. research reactors. [7] Since the consolidation of U.S. efforts under the GTRI umbrella in 2004, a total of 22 research reactors in the United States and other countries have been converted to LEU, and 12 had been shut down prior to conversion as of February 2011.[8]

In 2009, the Barack Obama administration announced efforts to lock down all nuclear weapons-usable materials in four years. Washington also convened a Nuclear Security Summit in 2010, attended by 38 heads of state and 47 states in total. The event has proven critical in leveraging a commitment from countries to participate in HEU reduction efforts.

U.S. Foreign Research Reactor Spent Nuclear Fuel (FRR SNF) Acceptance Program

Along with reactor conversion efforts, the United States takes back irradiated aluminum-based and TRIGA HEU and LEU fuels from U.S.-supplied research reactors. Fresh fuel is also accepted. Removal of the spent fuel addresses security and nonproliferation concerns. At the same time, the removal of spent fuel serves as an incentive for countries to convert to LEU. Reactor operators must commit to convert to LEU in order for the United States to accept their spent fuel. Approximately 5 metric tons of HEU and 15 metric tons of LEU are eligible to be shipped back to the United States. As of March 2010, there have already been 50 such shipments from 29 countries for a total of over 5,000 kg of uranium fuel and more than 9,175 fuel assemblies returned. The spent fuel acceptance program is scheduled to be completed in 2019. [9] Some U.S.-supplied reactor operators have yet to commit to convert to LEU and ship their fresh and spent HEU fuel back to the United States.

Soviet Program to Lower Enrichment Level in Exported Reactors

Also around 1978, the Soviet Union initiated a program with the goal of reducing the enrichment level of fuel (from 80% to 36%), for reactors supplied to its allies in Eastern Europe and some other parts of the world. The first stage of the Soviet program involved a reduction from 80% to 36% enriched fuels. By the late 1980s, higher density cermet fuel (ceramic in a metal matrix), with 36% enriched U-235, had been developed for use in the Soviet-supplied reactors abroad, and the Soviet Union stopped providing nuclear fuel of higher than 36% enrichment levels to these reactors. The program envisioned the development of new LEU fuels, however, activities to further reduce enrichment levels to below 20% were hampered in the late 1980s by the economic and political problems within the Soviet Union.

U.S.-Russian RERTR Program

After the breakup of the USSR, several former Soviet republics found themselves in possession of HEU-fueled research reactors. The conversion of these reactors to LEU required international attention, along with the lowering of the content of U-235 to below 20% in all Soviet-supplied reactors. In 1993, the U.S. Department of Energy initiated discussions with the Russian government and laboratories to restart efforts aimed at the conversion of Soviet-supplied reactors to LEU fuel. Russian scientists were invited to participate in annual International RERTR meetings.

In September 1994, representatives of the U.S. Department of Energy and the Russian Ministry of Atomic Energy signed a protocol of intent on cooperation in the development of higher-density 19.75% enriched uranium fuels, and on the feasibility demonstration of conversion to LEU fuel of specific reactors. Concrete work in this area started in 1996. The development and qualification of replacement LEU fuels took a long time.

In February 2005, U.S. President George W. Bush and Russian President Vladimir Putin signed the Bratislava Agreement, which committed them to joint work on nuclear weapons and fissile material security to prevent these materials from falling into terrorist hands. A bilateral interagency working group was tasked with reporting on the status of nuclear security cooperation to the presidents. Conversions of Soviet-supplied reactors followed suit.

In October 2005, the VR-1 reactor in the Czech Republic was the first of these reactors to complete the conversion and receive new LEU fuel. Russia also supplied Libya's IRT-1 reactor with LEU fuel in December 2005. Conversions of Libya's critical facility and its 10 MW reactor were completed in January 2006 and October 2006, respectively. The Soviet-supplied reactor at Vietnam's Dalat Nuclear Research Institute was converted in September 2007. In 2008, conversions of the VVR-SM research reactor at the Institute of Nuclear Physics in Uzbekistan and the WWR-M reactor at the Kiev Institute of Nuclear Research took place. In 2009, the Budapest reactor in Hungary was also converted. [10]

Notwithstanding its active participation in reducing civil HEU in Soviet-supplied reactors, Russia has been reluctant to make a commitment to convert or shut down its domestic HEU-fueled reactors. In a July 2009 Joint Statement on Nuclear Security Cooperation, U.S. President Barack Obama and Russian President Dmitriy Medvedev highlighted the importance of civil HEU minimization and committed to actively supporting these efforts through, inter alia, studying the feasibility of domestic reactor conversions. In February 2010, Rosatom confirmed the shutdown of three research reactors. Moscow and Washington have also signed an umbrella agreement to carry out feasibility studies for the conversion of six Russian reactors in December 2010.

Soviet-Origin HEU Fuel Repatriation

Washington became concerned about fissile material security in the former Soviet states in the early 1990s. Ad hoc operations to remove HEU from vulnerable sites were organized in 1994 and 1998 from nuclear facilities in the former Soviet republics.

The first operation, known as Project Sapphire, involved the removal of 581 kg of HEU, including some weapon-grade HEU, from the Ulba Metallurgy Plant, a nuclear fuel fabrication facility near Ust-Kamenogorsk, Kazakhstan. The considerable amount of material, its poor security, and information about Iranian interest in the material and the facility were driving forces behind the U.S. government's involvement. The Ulba HEU was transported to Oak Ridge National Laboratory in the United States in November 1994. [11]

The second operation - Auburn Endeavor - involved the removal on April 24, 1998 of approximately 4.3 kg of HEU fuel (mostly fresh HEU fuel) and 9.5 kg of fresh and spent fuel LEU from the Institute of Physics in Mtskheta, Georgia. The operation involved the governments of the United States, the United Kingdom, and Georgia. The material was transported to the Dounreay Nuclear Complex in Scotland. Subsequent HEU fuel removal operations from third countries have returned HEU material to the country of its origin; however, in some cases "repatriating" this fuel was not possible. [12]

After the terrorist attacks of September 11, 2001, efforts to convert research reactors, particularly in third countries, and to take back HEU fuel received new impetus. The United States and Russia began to work closely on removing fresh and spent HEU fuel from countries they had earlier supplied with research reactors and HEU fuel.

In August 2002, the Vinca Institute of Nuclear Science, located on the outskirts of Belgrade in the Republic of Serbia and Montenegro, became the focus of a tripartite effort by the United States, Russia, and the International Atomic Energy Agency to remove 48 kilograms of fresh (unirradiated) HEU research reactor fuel. The removed material consisted of 5,046 cylinders of 80% enriched fresh fuel. This amount probably would be sufficient for a relatively simple gun-type nuclear device. With a more sophisticated implosion-type design, this amount could yield two and one-half bombs. [13]

Although U.S. knowledge of the HEU at Vinca and its vulnerability dates back to at least 1994, the opportunity to recover the material was realized only in summer 2002. Only then were the United States and Russia finally able to come to an agreement about the return of Soviet-supplied HEU fuel to Russia (the actual government agreement was signed later, in 2004). After 9/11, the United States government became much more aggressive in addressing nuclear materials vulnerability worldwide and pursued this issue with urgency. The Vinca operation was a breakthrough in the repatriation of Soviet-supplied HEU fuel to its country of origin. The engagement of a non-governmental organization, the Nuclear Threat Initiative, played a crucial role in convincing the Yugoslav government to part with the HEU. NTI provided $5 million to address radioactive hazards at Vinca, and this incentive, along with the funding for the operation itself by the U.S. government, made it possible to conclude the deal to remove the HEU from the country.[13]

The operation started on August 14, 2002 and involved the repackaging of the material into transportation containers under strict safeguards and physical protection measures, proper interim storage of these containers, and subsequent transfer of the HEU fuel to Russia. All work was verified by IAEA inspectors. Russian and U.S. specialists were also on-site to oversee and direct the operation. Many details of the operation were kept secret. Yet to ensure safe and secure transport of the material to a Russian cargo plane, 1,200 military and police officers were dispatched along the route to the Belgrade airport. The plane with the HEU departed Belgrade at 8:00 am on August 22. Four hours later, the material arrived in Dmitrovgrad, Russia, and was transferred to a secure storage depot until it was downblended to below 20% enrichment level. [13]

Since 2002, Russia has accepted Soviet-origin fuel containing HEU in the framework of the Russian Research Reactor Fuel Return Program (RRRFR). The United States, Russia, and the International Atomic Energy Agency are closely involved in each HEU fuel take-back operation. For example, as part of the Global Threat Reduction Initiative, the United States funded, and together with the IAEA jointly monitored and executed, the repatriation of HEU from the Otwock research reactor facility in Poland in 2006 and 2007 to Russia's Luch Scientific Production Association for downblending. All returned fresh HEU fuel is downblended in Russia to below 20% enrichment.

In a joint November 7, 2003 statement, the U.S. Secretary of Energy and the Minister of the Russian Federation for Atomic Energy underscored the importance of the two countries' cooperation in the area of HEU removals: "HEU can be directly used in manufacturing nuclear weapons. Our common objective consists of reducing, to the greatest extent possible, and, ultimately, eliminating the use of such materials in civilian nuclear activity."

In May 2004, the U.S. and Russian governments signed a formal agreement on cooperation on the transfer of Soviet/Russian origin research reactor nuclear fuel to Russia.[14] Plans provide for the return of all spent and fresh fuel.

Since May 2004, GTRI has successfully led efforts to remove more than 1,490 kg of Russian-origin HEU in thirty-five shipments. Of these, over 450 kg were fresh fuel and 980 kg were spent fuel. [15] The table below lists the removal of Soviet-origin fuel under RRRFR and GTRI since 2002.

In addition to converting facilities to use LEU fuel and repatriating HEU, there have also been efforts to consolidate fresh and spent HEU fuel at a smaller number of relatively secure locations. The U.S.-Russian Materials Consolidation and Conversion (MCC) Program, established in 1999, reduces excess Russian civilian HEU by blending it down into LEU. This program has blended down 12 tons of HEU, and has led to the removal of HEU from the Krylov Shipbuilding Research Institute. [16]

Both the United States and Russia have large quantities of HEU that are no longer needed in their defense programs. In Russia, excess HEU from weapons is blended down to LEU within the framework of the "Megatons to Megawatts" program (also known as the HEU-LEU program). According to the 1993 U.S.-Russia agreement, 500 metric tons of weapons HEU are slated for downblending by 2013. The resulting LEU is then shipped to the United States to be used in LEU fuel for commercial nuclear power generation. The United States initially declared some 174 metric tons of HEU as excess to military needs, designating this material as civilian.[17] An additional 200 metric tons were officially removed from the U.S. weapons stockpile in November 2005; of this amount, approximately 20 metric tons will be down-blended to LEU.[18] Since the amount of HEU that is actually excess to military needs is likely far greater than the amount that has officially been declared excess to date, there have also been calls to speed up the various blenddown programs. An effort spearheaded by the Nuclear Threat Initiative involves a detailed study of the Russian nuclear complex to determine the options for speeding up the U.S.-Russian HEU-LEU program, and what costs various scenarios entail.[19]

EXPORT CONTROLS AND OTHER INTERNATIONAL EFFORTS TO LIMIT CIVILIAN HEU USE

Nuclear Suppliers Group Guidelines

There is no explicit ban on the export of HEU for civilian purposes as long as countries subscribe to IAEA full-scope safeguards. The Nuclear Suppliers Group (NSG) was established in 1975 to ensure that suppliers applied a uniform approach to nuclear exports so that nuclear cooperation did not contribute to proliferation. HEU, as nuclear material of direct application for weapons purposes, was included in the so-called Trigger List. Any export of items from this list requires the application of safeguards on all fissionable materials (not only the supplied material), in the recipient's nuclear activities. These safeguard arrangements are also known as "full-scope IAEA safeguards." (Part one of the IAEA Information Circular INFCIRC/254 contains the Guidelines for Nuclear Transfers.)

In June 2011, the NSG agreed to more stringent rules governing uranium enrichment and spent fuel reprocessing (ENR) technology. These new rules, among other criteria, prohibit the export of ENR technology to states that have not signed or are not in compliance with the NPT, and states that do not allow full-scope IAEA safeguards or additional inspections and monitoring as part of the Additional Protocol.[20]

U.S. 1992 Schumer Amendment

Some countries have instituted even more restrictive export control regulations than those of the NSG. In 1992, the United States, for example, adopted the so-called "Schumer Amendment" to the Energy Policy Act, which required foreign reactors supplied with HEU fuel by the United States to commit to convert to LEU as quickly as possible, and prohibited U.S. HEU exports if foreign reactors did not undertake such obligations. The implementation of this amendment, in combination with LEU fuel development and a drop in the construction of new reactors, facilitated a rapid decline in U.S. HEU exports from an annual peak of nearly three tons in the late 1960s to a few tens of kilograms or less by the early 1990s—a reduction of 99%.[21]

In 2005, an Energy bill passed by Congress included an amendment relaxing restrictions on HEU exports for medical isotope production. The primary beneficiaries of the new law were big producers of medical radioisotopes, who claimed that conversion to LEU would be too costly and could disrupt production of needed medical isotopes. This amendment, passed after heavy lobbying efforts by Canadian medial isotope producer MDS Nordion, permitted the export of U.S. HEU to medical isotope producers even if they did not commit to convert to LEU. A bill to repeal this amendment, the American Medical Isotopes Act, passed the house on a 400-17 vote, and gained the approval of the Senate Energy and Commerce Committee. The bill was, however, placed on "hold," thus preventing it from reaching the full Senate in 2010. [22] As of summer 2011, new legislation to repeal this amendment is advancing in Congress.

Other countries don't impose these restrictions, and in some cases HEU consumers were able to substitute U.S. HEU exports with exports from other countries. Russia, for example, concluded agreements to supply HEU for research reactors in some EU countries (for reactors in Canada, France, Germany, and the Netherlands).

RESOURCES

Websites

• "Office of Global Threat Reduction," U.S. National Nuclear Security Administration, http://nnsa.energy.gov.
• "Reduced Enrichment for Research and Test Reactors," Argonne National Laboratory, www.rertr.anl.gov.
• "Removing Material From Vulnerable Sites" in NTI Securing the Bomb report, www.nti.org.
• Fissile Materials Working Group, fmwg.presstools.org/about.
• "Global HEU Phaseout," a Nuclear Proliferation Prevention Project at the University of Texas at Austin, www.heuphaseout.org.

Articles and Reports

• Matthew Bunn, Securing the Bomb 2010 (Cambridge, MA and Washington, D.C.: Belfer Center for Science and International Affairs and the Nuclear Threat Initiative, November 2010), www.nti.org.
• Mary Beth Nikitin, "Securing Nuclear Materials: The 2010 Summit and Issues for Congress," CRS Report for Congress, May 2011.
• Robert Golan-Vilella, Michelle Marchesano, and Sarah Williams, "The 2010 Nuclear Security Summit: A Status Update," Arms Control Association and the Partnership for Global Security, April 2011, www.armscontrol.org/reports.
• Special section on "The Global Elimination of Civilian Use of Highly Enriched Uranium," The Nonproliferation Review, July 2008.
• Philipp Bleek, "Global Cleanout: An Emerging Approach to the Civil Nuclear Material Threat," (Cambridge, MA and Washington, D.C.: Belfer Center for Science and International Affairs and the Nuclear Threat Initiative, September 2004), http://bcsia.ksg.harvard.edu.
• Oleg Bukharin, Christopher Ficek, and Michael Roston, "U.S.-Russian Reduced Enrichment for Research and Test Reactors (RERTR) Cooperation," in RANSAC Policy Update, Summer 2002, www.ransac.org.
• Cristina Chuen, "Reducing the Risk of Nuclear Terrorism: Decreasing the Availability of HEU," CNS feature story, May 2005, http://cns.miis.edu.
• Robert L. Civiak, "Closing the Gaps: Securing High Enriched Uranium in the Former Soviet Union and Eastern Europe," May 2002, p. 9, Federation of American Scientists, www.fas.org.
• Charles Ferguson and William Potter, eds., The Four Faces of Nuclear Terrorism (Abindgdon, Oxfordshire, UK: Routledge, June 2005), http://cns.miis.edu.
• Alexander Glaser and Frank N. von Hippel, "Global Cleanout: Reducing the Threat of HEU-Fueled Nuclear Terrorism," Arms Control Today, January/February 2006, www.armscontrol.org.
• Morten Bremer Maerli and Lars van Dassen, "Eliminating Excessive Stocks of Highly Enriched Uranium," Pugwash Issue Brief, Vol. No. 1 (April 2005), www.pugwash.org.
• Frank von Hippel, "A Comprehensive Approach to Elimination of Highly-Enriched-Uranium From All Nuclear-Reactor Fuel Cycles," Science and Global Security, No. 12 (2004), www.princeton.edu.

Sources:
[1] For an historical overview, see Anya Loukianova and Cristina Hansell, "Leveraging U.S. Policy for a Global Commitment to HEU Elimination," The Nonproliferation Review, July 2008.
[2] Armando Travelli, R. Domagala, Jim Matos, J. Snelgrove, "Development and Transfer of Fuel Fabrication and Utilization Technology for Research Reactors," paper presented at International Conference on Nuclear Technology Transfer, Buenos Aires, November 1, 1982. Several other countries, including Canada, France, Germany, and Japan, established similar programs in the 1970s, while the IAEA provided a forum for cooperative technical research. In the late 1970s, the Soviet Union began replacing very highly enriched uranium fuels in research reactors outside of the USSR with 36 percent enriched fuel.
[3] For an excellent summary of RERTR's impact on U.S. HEU exports, see, Alan J. Kuperman, "Codifying the Phase-Out of Bomb Grade Fuel for Research Reactors," in Paul Leventhal, Sharon Tanzer, and Steven Dolley, eds., Nuclear Power and the Spread of Nuclear Weapons (Washington, DC: Brassey's, 2002), pp. 251-260.
[4] See, for example, Alexander Glaser and Frank N. von Hippel, "Global Cleanout: Reducing the Threat of HEU-Fueled Nuclear Terrorism," Arms Control Today, January/February 2006, www.armscontrol.org.
[5] See, for example, Paul Leventhal and Alan Kuperman, "RERTR at the Crossroads: Success or Demise?" paper presented to the RERTR 1995 International Meeting, Paris, France, September 18, 1995,
[6] "Office of Global Threat Reduction," U.S. National Nuclear Security Administration, http://nnsa.energy.gov.
[7] Christopher Landers, "Global Threat Reduction Initiative: Furthering HEU Minimization Through Conversions," 11 October 2010, presented at the RERTR 32nd Annual International Meeting.
[8] NNSA, "GTRI: Reducing Nuclear Threats," February 11, 2011, http://nnsa.energy.gov.
[9] C.E. Messick, J.L. Taylor, M.T. Niehus, C. Landers, "United States Foreign Research Reactors (FRR) Spent Nuclear Fuel (SNF) Acceptance Program: 2010 Update," paper presented at the 2010 RRFM Conference in Morocco, March 2010, http://euronuclear.org.
[10] NNSA, "GTRI: Reducing Nuclear Threats," February 11, 2011, http://nnsa.energy.gov.
[11] William C. Potter, "Project Sapphire: U.S.-Kazakhstani Cooperation for Nonproliferation," in John M. Shields and William C. Potter, eds., Dismantling the Cold War: U.S. and NIS Perspectives on the Nunn- Lugar Cooperative Threat Reduction Program (Cambridge: MIT Press, 1997), pp. 345-362.
[12] Center for Nonproliferation Studies, "Georgia: Operation Auburn Endeavor," Nuclear Threat Initiative, www.nti.org.
[13] See William C. Potter, Djuro Miljanic, and Ivo Slaus, "Tito's Nuclear Legacy," Bulletin of the Atomic Scientists, 56 (March/April 2000), pp. 63-70; Philipp C. Bleek, "Project Vinca: Lessons for Securing Civil Nuclear Material Stockpiles," The Nonproliferation Review 10 (Fall-Winter 2003).
[14] "Joint Statement of U.S. Secretary of Energy Spencer Abraham and Minister of the Russian Federation for Atomic Energy Aleksandr Rumyantsev on Cooperation to Transfer Russian-Origin High-Enriched Uranium Research Reactor Fuel to the Russian Federation," November 7, 2003, www.nti.org. Agreement between the Government of the United States of America and the Government of the Russian Federation Concerning Cooperation for the Transfer of Russian-Produced Research Reactor Nuclear Fuel to the Russian Federation, May 27, 2004.
[15] NNSA, "GTRI: Reducing Nuclear Threats," February 11, 2011, http://nnsa.energy.gov.
[16] Matthew Bunn, Securing the Bomb 2010 (Cambridge, MA and Washington, DC: Belfer Center for Science and International Affairs and the Nuclear Threat Initiative, November 2010), www.nti.org, p. 37.
[17] For information on the U.S. program, see "Reducing Excess Stockpiles: U.S. Highly Enriched Uranium Disposition" Securing the Bomb 2005, www.nti.org.
[18] "DOE to Remove 200 Metric Tons of Highly Enriched Uranium from U.S. Nuclear Weapons Stockpile," DOE Press Release, November 7, 2005, www.energy.gov.
[19] Nuclear Threat Initiative, "Options for Expanding Conversion of Russian Highly Enriched Uranium," December 2010.
[20] Mark Hibbs, "New Global Rules for Sensitive Nuclear Trade," Carnegie Endowment Nuclear Energy Brief, 28 July 2011, www.carnegieendowment.org.
[21] Alan J. Kuperman, "Civilian Highly Enriched Uranium and the Fissile Material Convention," in Paul L. Leventhal, ed., Nuclear Power and the Spread of Nuclear Weapons (Dulles: Brassey's Inc., 2002), pp. 249-260, as cited in Alan Kuperman, "Bomb-grade bazaar," Bulletin of the Atomic Scientists, March/April 2006, www.thebulletin.org.
[22] Alan Kuperman, "Stop Holding onto Dangerous Nuclear Material," The Hill, 27 September 2010, http://thehill.com.