Global Cleanout of Weapons-Usable Nuclear Materials

The Issue | Obstacles | Q & A | Quick Facts | Legislation | Agreements | Talking Points | Recommendations

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The Issue

In the second half of the twentieth century, the United States and the Soviet Union dispersed weapons-grade highly enriched uranium (HEU) for use in research reactors in scores of countries around the world.[1] Today, 10 metric tons of HEU, enough for about 400 nuclear weapons, is estimated to remain in those civilian research reactors.[2] Most of this dangerous material is inadequately secured, and the programs to remove and replace the HEU with non-weapons-usable low-enriched uranium (LEU) are not adequately funded. In 2004, the US consolidated its programs into the Department of Energy's Global Threat Reduction Initiative (GTRI), which has increased the pace of securing and removing these materials. However, much work remains to be done.

In order to prevent nuclear proliferation, policy makers most often focus on the vast stockpiles of nuclear weapons and materials in Russia. According to many observers, however, the weakest link in the international non-proliferation regime is the security at civilian research reactors around the world that use (or store) HEU. There are roughly 135 HEU research reactors or related facilities that still use HEU as fuel.[3]

Though plutonium has become the predominant fissile material in sophisticated nuclear weapons programs, HEU is easier to handle and lends itself to the simplest weapon designs most likely to be used by a terrorist or terrorist state.[4] For example, when Iraq tried to develop a nuclear capability before the 1991 Gulf War, it used 36 kilograms of HEU left over from one Russian and two French supplied research reactors.[5] Designs for a nuclear weapon found in the caves of Afghanistan after al Qaeda forces had fled indicate that they too have an interest in developing such a device.

Civilian HEU research reactors, especially in Russia and the other states of the former Soviet Union (FSU) are often dangerously insecure. Scarce funding, widespread corruption, and general economic and political uncertainty have severely hampered security measures at many of these facilities. Their accounting of fissile material is often done through archaic or informal methods, such as hand counting, that are prone to manipulation and human error. In addition, the security of weapons-grade material often relies on store-bought padlocks or even wax seals of the type used centuries ago.[6] As a result, multiple cases of theft or attempted theft have been reported since the fall of the Soviet Union.[7] In addition to active reactor fuel, many facilities also house large amounts of spent HEU. Spent fuel from the smaller research reactors can remain highly enriched, is small enough for easy transport, and often is no longer radioactive enough to deter a terrorist from stealing it.[8] Moreover, terrorists willing to commit suicide are not deterred by radioactivity of any level.

Nuclear reactors besides research reactors also give cause for concern; Russia continues to use HEU fuel in nuclear icebreakers and is building floating reactors that will provide energy to remote areas.[9] Production reactors for medical isotopes that use HEU are also proliferation risks; "worldwide isotope production utilizes approximately 85 kilograms of HEU annually."[10]

US Government Programs

Originally, the United States imported spent fuel from nuclear facilities it helped create abroad, but the Department of Energy's (DOE) Offsite Fuels Policy, or "Takeback" program, expired in 1988. Spent fuel of proliferation concern began building up at potentially unsecured locations. New programs were not reinstated until 1996. As a result, new environmental and security hazards have been created.[11] GTRI was established in 2004 to address these pressing issues in a coordinated way.

One of GTRI's main components is the Reduced Enrichment for Research and Test Reactors (RERTR) program. Created in 1978, RERTR explores ways to convert both domestic and US-origin foreign research reactors to LEU fuel, which cannot be used to manufacture nuclear weapons.[12] After the fall of the Soviet Union caused a significant drop in security for many Russian-origin reactors, the US and Russia signed an agreement, pledging cooperation in the conversion and development of LEU fuel for Soviet-designed research reactors.[13] With the advent of GTRI, RERTR aimed to accelerate its work by targeting 129 research or test reactors around the globe for conversion by 2018; as of February 2007, 46 of those reactors had been converted.[14] After the HEU is removed from the site, it is "downblended" by mixing it with very low-enriched or un-enriched uranium to produce LEU that can be used to fuel commercial and research reactors, but not to make nuclear weapons. The RERTR program is also currently working to develop LEU fuel that will replace the HEU used to produce Molybdenum-99, the most widely used diagnostic radioisotope in the world.[15]

The US government also operates clean-out programs that do not facilitate reactor conversion. The Foreign Research Reactor Spent Nuclear Fuel Acceptance program (FRR SNF) allows facilities in 41 countries to return up to twenty metric tons of spent US-origin nuclear fuel as long as those facilities are using LEU fuel or agree to use LEU fuel in the future. High-income countries must pay a management and acceptance fee, as well as pay for the transportation of the fuel; all other countries pay no fees and receive US subsidies for the fuel's transportation.[16] The Emerging Threats and Gap Material program gives the US a vehicle to remove vulnerable nuclear material not covered by other clean-out programs.[17] GTRI also includes programs to remove dangerous radiological material and to secure HEU in facilities from which it will not be cleaned out.

Joint Initiatives

The dire economic situation in Russia in the 1990's prevented a similar Russian comprehensive fuel reclamation effort; and the security at Soviet-origin reactors began to falter, creating a substantial proliferation risk. At first, the US and Russia responded to identifiable proliferation threats through ad hoc efforts. For example, Operation Sapphire, a joint US-Russian operation, removed 581 kilograms of HEU from a nuclear fuel fabrication facility in Kazakhstan in 1994.[18] Building from this initial success, the United States, working with Russia and the International Atomic Energy Agency (IAEA), launched the Russian Research Reactor Fuel Return (RRRFR) program in 1999 to facilitate the safe transport and disposal of Russian-origin fuels.[19] Only reactors that agree to either convert to LEU or shut down completely qualify for US assistance.[20] By the end of September 2007, over 500 kilograms of the 1,781 kilograms of Russian-origin HEU targeted by the program will have been repatriated.[21]

The flexibility to provide adequate incentives (assisting in cleanup, finding new work for employees) for institutions to participate is important to convince research facility directors to convert from HEU to LEU. The incentives involved in previous removal operations varied widely. For example, the United States agreed to give Kazakhstan $20 to $30 million in additional funds for other projects in return for relinquishing the material in Operation Sapphire. Only $4 million for the purchase of new LEU fuel, however, sufficed to convince Romanian authorities to cooperate with HEU removal in September 2003.[22]




  • Some countries may not have sufficient financial resources to convert research reactors to LEU fuels without assistance or incentives towards that end.
  • At some facilities, records regarding nuclear material can be lacking, inaccurate, or even non-existent.
  • Citizens in the United States and other countries have resisted importing nuclear material for downblending because of environmental concerns.
  • Many reactor operators have resisted conversion to LEU because of technical concerns about the viability of new fuels to maintain the same level of performance. However, in the cases of most reactors, new LEU fuels promise to perform adequately; and research is ongoing to design LEU fuels that meet the needs of the other reactors.



Q: Why should the United States bear a significant burden in this kind of effort when much of the problem is a legacy of the Soviet Union and other nations are also at risk of a terrorist attack?
A:Multilateral cooperation is highly desirable in any situation that cuts across political and cultural boundaries and should certainly be pursued. Nevertheless, the US cannot afford to delay a global cleanout-at the risk of a catastrophic terrorist attack against us at the cost of hundreds of thousands of lives-while the attempt to get more of the international community on board proceeds.

Q: What are High Enriched Uranium (HEU) and Low Enriched Uranium (LEU)?
A:The International Atomic Energy Agency defines HEU as uranium with a concentration of the isotope 235U of 20% or more. Ninety percent 235U is considered weapons grade, but all HEU is usable in nuclear weapons. LEU is Uranium with a 235U concentration below 20% and cannot sustain the chain reaction necessary for a nuclear explosion. Approximately 2/3 of the total services necessary to produce weapons-grade uranium goes into enriching it from natural uranium (usually .7% 235U) to LEU (3.6% 235U for power generation). The remaining 1/3 of the total services goes into enriching the LEU from 3.6% 235U to 90% 235U, weapons-grade uranium.[23]


Quick Facts

  • An estimated 10 metric tons of HEU, enough to build more than 400 nuclear weapons, are housed in civilian research reactors and institutions worldwide.
  • There are at least 135 operating research reactors fueled with HEU in more than 40 countries.
  • HEU from a research reactor almost gave Iraq a nuclear capability before the First Gulf War.
  • A 10-kiloton bomb, if detonated in downtown Manhattan, could kill half a million people and force evacuation of the island. The bomb dropped on Hiroshima on August 6, 1945, was about 15 kilotons.
  • Unlike plutonium, to which even limited exposure is extremely hazardous, HEU can be safely handled with bare hands.
  • In Fiscal Year 2008, the Reduced Enrichment for Research and Test Reactors (RERTR) program intends to convert a total of ten reactors in the following countries: Bulgaria, the Netherlands, the United Kingdom, Vietnam, South Africa, Japan, and the US.
  • "Little Boy," the nuclear weapon detonated over Hiroshima, contained 64 kilograms of HEU. However, the IAEA now says that only 25 kilograms of HEU is necessary to build a nuclear weapon.[24] The amount of uranium needed falls as the percentage of 235U rises.


Recent Legislation

  • The most recent Continuing Resolution for FY 2007 appropriations (Public Law 110-5) provides GTRI with 8.1 percent more funding than requested by the Bush administration.
  • The 9/11 Commission Combating Proliferation Implementation Act (HR 422), which was not enacted, called for the authorization of an additional $100 million each fiscal year for global nuclear cleanout efforts. This bill has been reintroduced as HR 360 in the current Congress.
  • The Omnibus Nonproliferation and Anti-Nuclear Terrorism Act of 2005 (HR 665), which was not enacted, called for the enhancement of the Global Threat Reduction Initiative by transferring authority for the program from the Secretary of Energy to the President and broadly authorizing the President to "take such other actions as necessary to implement" GTRI.
  • The Ronald W. Reagan National Defense Authorization Act for FY2005 (Public Law 108-375) provided explicit statutory authority for the Global Threat Reduction Initiative, a program that the Administration had established in 2004 in order to accelerate the removal of fissile material from vulnerable sites around the world. The program targets fissile material, radiological material and related equipment.


Applicable Treaties, Legislation, and Other International Agreements

  • The Global Initiative to Combat Nuclear Terrorism, announced by Presidents Bush and Putin at the 2006 G8 Summit in St. Petersburg, aims to enhance cooperation among like-minded states to secure nuclear material at its source.
  • United Nations Security Council Resolution 1540 (2004) mandates that all states enact national legislation criminalizing the possession and attempted acquisition of WMDs and WMD materials. States must also work to build their capacities to prevent illicit trafficking of WMD materials across their borders by state and non-state actors.
  • The G8 Global Partnership Against the Spread of Weapons and Materials of Mass Destruction, created at the Kananaskis Summit in June 2002, solidified the commitment of the G8 nations to devote $20 billion ($10 billion from the US) over 10 years to securing WMD around the globe and to addressing various related environmental and safety concerns. However, that funding pledge involved little new money beyond that which was already contemplated by the G8 nations; and even so, commitments have yet to reach $20 billion and spending has lagged.[25]


Talking Points

  • Enriching uranium to a weapons-usable level is so difficult that only a handful of states have been able to master the technology; it is unrealistic to believe that a terrorist group could develop an enrichment capacity without having the facilities discovered.[26] Thus, theft or illicit purchase is the prime avenue for terrorist acquisition of HEU, making reactor conversion and material security even more important.
  • HEU, unlike plutonium, poses very little health risks to handlers, making it much easier to use in nuclear weapons.[27] Furthermore, the gun-type bomb that a terrorist group would use (due to the comparative complexity of an implosion-type weapon) necessitates the use of HEU to prevent premature detonation.[28] Thus, HEU is the nuclear material of choice for terrorists.
  • As shown on September 11th and further demonstrated at other locations around the world since, terrorists attack what they perceive will expose vulnerability in a government or group. If nuclear material remains vulnerable to theft, it could only be a matter of time until terrorists obtain such material and use it against their perceived enemy, including US territory, population, or interests abroad.
  • Terrorists and hostile states are already trying to acquire material for nuclear devices and have significant financial resources to use for this purpose. Osama Bin Laden has called the acquisition of WMD a "religious duty" for al Qaeda; and credible intelligence points to a significant effort to this end. Vulnerable HEU stockpiles should be secured as soon as possible.



  • A National Security Council designee should spearhead an interagency process to provide a detail and timely reassessment of the global role of nonproliferation efforts in today's context, including those that have arisen in the past few years. This assessment should include provisions on how to accelerate the cleanout of vulnerable nuclear materials.
    [See Book Recommendation #1]
  • Several countries involved in the G8 Global Partnership Against Weapons and Materials of Mass Destruction provide funding for material cleanout. The US Government should encourage wider collaboration internationally to better leverage Global Partnership funding across national boundaries.
    [See Book Recommendation #3]
  • At the start of any program, the US agency involved should build consensus with the respective host country regarding perceived threats. For example, Russia and the US differ in their threat perceptions of radiological dispersal devices and improvised nuclear devices, meaning their priorities for securing specific types of nuclear material differ as well.
    [See Book Recommendations #6]
  • Create a bicameral congressional task force whose objective is to regularly provide briefings from a broad array of the actors involved in actual implementation of nonproliferation initiatives. Greater Congressional understanding of the relevant issues and activities could lead to more effective programming and greater support for expediting the removal of vulnerable nuclear material from research reactors. The Department of Energy's National Nuclear Security Administration program directors should be encouraged to actively promote nonproliferation activities and to participate in Congressional briefings.
    [See Book Recommendations #7 and #19]
  • Channel scientist redirect programs to meet the needs of other government programs. US programs to secure nuclear weapons and materials create a demand in Russia for security technology. Former nuclear weapons scientists can be instrumental in designing new security technology or, in a best-case scenario, technology that will eliminate the need to use HEU in research reactors. By coordinating programs to redirect scientists with internal US Government programs to achieve specific technological advances needed to solve our own energy, nonproliferation, counterterrorism, intelligence and other needs, the US could better achieve its existing nonproliferation goals with respect to brain drain while exploring potential technological solutions to existing security concerns at lower cost.
    [See Book Recommendation #8 and #17]
  • The United States government should act to appoint an independent broker to help generate a "business roundtable" dialogue between overworked agency implementers and currently disinterested private sector players. Global cleanout programs provide ample opportunities for private sector collaboration.
    [See Book Recommendation #9]
  • The State Department should create an "information clearinghouse" for US Government-wide nonproliferation activities. The confluence of US Government programs, G8 Global Partnership programs, the Global Initiative, and other nonproliferation programs necessitates a single gateway for information and a mechanism for transparency amongst the multiple agencies and actors.
    [See Book Recommendation #22]

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[1] Philipp C. Bleek, "Global Cleanout of Civil Nuclear Material: Toward a Comprehensive, Threat-Driven Response," Strengthening the Global Partnership Issue Brief #4, September 2005, pg. 1, accessed at:

[2] Ibid.

[3] Matthew Bunn and Anthony Weir, Securing the Bomb 2006, Harvard University and the Nuclear Threat Initiative, July 2006, p. 19.

[4] Matthew Bunn, "Preventing Nuclear Terrorism: Testimony of Matthew Bunn for the Subcommittee on National Security, Committee on Government Reform, United States House of Representatives, September 24, 2002," accessed at:

[5] Oleg Bukharin, Christopher Ficek, and Michael Roston, "U.S.-Russian Reduced Enrichment for Research and Test Reactors (RERTR) Cooperation," RANSAC Policy Update, Summer 2002, p. 2, accessed at:

[6] Cynthia McFadden, "Hunting Loose Nukes in Eastern Europe," ABCNews Nightline, October 13, 2005, accessed at:

[7] International Atomic Energy Agency, "IAEA Illicit Trafficking Database," accessed at:

[8] Matthew Bunn and Anthony Weir, "Securing the Bomb: Converting Research Reactors," Nuclear Threat Initiative, January 12, 2004, accessed at:

[9] BBC News, "Floating Atomic Plant for Russia," BBC News Online, June 14, 2006, accessed at:

[10] A. J. Kuperman, "The Global Threat Reduction Initiative and Conversion of Isotope Production to LEU Targets," Conference Paper (Washington: Nuclear Control Institute, 2004), accessed at:

[11] Bunn and Weir, Securing the Bomb 2006.

[12] HEU is defined by the IAEA as Uranium composed of greater than 20% 235U; LEU is composed of less than 20% 235U. LEU still presents serious dangers and can produce a chain reaction for a nuclear explosion, but nuclear devices using LEU produce significantly less yield and require much more material than those using HEU. An LEU weapon would be substantially larger than an HEU weapon and produce a weaker explosion, making it less than ideal for use by terrorists or rogues states. Dangers from LEU are still an issue that must be addressed, but this is outside the scope of this study. Overall, relative risk is lower with LEU than HEU.

[13] "Agreement between the U.S. Department of Energy and The Federal Nuclear and Radiation Safety Authority of the Russian Federation for Cooperation on Enhancing the Safety of Russian Nuclear Fuel Cycle Facilities and Research Reactors," June 1995, accessed at:

[14] Office of the Chief Financial Officer, "FY 2008 Congressional Budget Request: National Nuclear Security Administration," US Department of Energy, February 2007, p. 517, accessed at:

[15] Office of Defense Nuclear Nonproliferation, "Reduced Enrichment for Research and Test Reactors," US Department of Energy, accessed at:

[16] Office of Defense Nuclear Nonproliferation, "Emerging Threats," US Department of Energy, accessed at:

[17] Office of Defense Nuclear Nonproliferation, "Russian Research Reactor Fuel Return (RRRFR)," US Department of Energy, accessed at:

[18] Matthew Bunn and Anthony Weir, "Securing the Bomb: Securing Nuclear Warheads and Materials: Removing Material from Vulnerable Sites," Nuclear Threat Initiative, January 2004, accessed at:

[19] Office of Defense Nuclear Nonproliferation, "Russian Research Reactor Fuel Return (RRRFR)," US Department of Energy, accessed at:

[20] Bunn and Weir, "Removing Material from Vulnerable Sites."

[21] Office of the Chief Financial Officer, "FY 2008 Congressional Budget Request: NNSA."

[22] Bunn and Weir, "Removing Material from Vulnerable Sites."

[23] Arjun Makhijani, et. al., "Uranium Enrichment: Facts to Fuel an Informed Debate on Nuclear Proliferation and Nuclear Power," Science for Democratic Action 13, no. 1 (March 2005), accessed at:

[24] Tariq Rauf, "Drawing Safeguards Conclusions," Presentation to the 2004 NPT Preparatory Committee (April 29, 2004), accessed at:

[25] Group of Eight Leaders, "The G8 Global Partnership Against the Spread of Weapons of Mass Destruction," Kananaskis, Canada, June 27, 2002, accessed at:

[26] Jeffrey Boutwell, Francesco Calogero, and Jack Harris, "Nuclear Terrorism: The Danger of Highly Enriched Uranium (HEU)," Pugwash Issue Brief (Washington: Pugwash, 2002), accessed at:

[27] Ibid.

[28] Owen R. Cote, Jr., "Appendix B: A Primer on Fissile Materials and Nuclear Weapon Design," Avoiding Nuclear Anarchy: Containing the Threat of Loose Russian Nuclear Weapons and Fissile Material (Cambridge: Harvard University, 1996), accessed at:

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Last Updated on May 30, 2007