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GTRI: Reducing Nuclear Threats

May 29, 2014


In 2004 NNSA established the Global Threat Reduction Initiative (GTRI) in the Office of Defense Nuclear Nonproliferation to, as quickly as possible, identify, secure, remove and/or facilitate the disposition of high risk vulnerable nuclear and radiological materials around the world that pose a threat to the United States and the international community.

GTRI’s mission is to reduce and protect vulnerable nuclear and radiological material located at civilian sites worldwide. GTRI achieves its mission via three initiatives which provide a comprehensive approach to preventing terrorists’ access to nuclear and radiological materials. These three initiatives are:

  1. Convert: Convert research reactors and isotope production facilities from the use of highly enriched uranium (HEU) to low enriched uranium (LEU) or verify their shutdown;
  2. Remove: Remove or confirm the disposition of excess nuclear and radiological materials; and
  3. Protect: Protect high priority nuclear and radiological materials from theft.


Since its inception, GTRI has made significant progress to reduce the risk posed by vulnerable civilian nuclear and radiological materials, which could be used by terrorists to make an improvised nuclear device or a radiological dispersal device (RDD), or "dirty bomb.”

GTRI and its predecessor programs have converted or verified the shutdown of 88 HEU research reactors and isotope production facilities; removed or confirmed the disposition of more than 5,140 kilograms of HEU and plutonium – more than enough material for more than 205 nuclear bombs; secured more than 775 bombs worth of HEU and plutonium associated with the BN-350 reactor in Kazakhstan; secured more than 1,700 radiological sites around the world containing millions of curies – enough for tens of thousands of large dirty bombs; recovered more than 36,000 orphan and disused radiological sources in the United States; and recovered 810 radioisotope thermoelectric generators from Russia containing millions of curies of activity.

GTRI has greatly accelerated the NNSA’s efforts to reduce nuclear and radiological threats since the establishment of GTRI in May 2004.


Since May 2004, GTRI has:

  • Successfully converted to LEU fuel or verified the shutdown of 49 HEU research reactors in 25 countries, including Argentina, Australia, Bulgaria, Canada, Chile, China, the Czech Republic, France, Germany, Hungary, India, Japan, Kazakhstan, Libya, the Netherlands, Portugal, Poland, Russia, Ukraine, the United Kingdom, United States, Uzbekistan, and Vietnam; and verified the cessation of the use of HEU targets for isotope production in Indonesia.
  • Accelerated the establishment of a reliable supply of the medical isotope molybdenum-99 (Mo-99) produced without HEU by establishing partnerships with South Africa, Belgium, and the Netherlands to convert Mo-99 production from HEU targets to LEU targets, and with four domestic commercial entities to produce Mo-99 in the United States with non-HEU technologies.


Since May 2004, GTRI has:

  • Successfully removed or confirmed the disposition of more than 4,100 kilograms of HEU and plutonium (more than enough material for 165 nuclear weapons);
  • Removed all weapons-usable HEU from 16 countries and Taiwan, including: Greece (December 2005), South Korea (September 2007), Latvia (May 2008), Bulgaria (August 2008), Portugal (August 2008), Romania (June 2009), Taiwan (September 2009), Libya (December 2009), Turkey (January 2010), Chile (March 2010), Serbia (December 2010), Mexico (March 2012), Ukraine (March 2012), Austria (December 2012), and Czech Republic (April 2013); and
  • Removed more than 36,000 disused and unwanted radiological sources from sites across the United States.


Since May 2004, GTRI has:

  • Completed physical protection upgrades at more than 1,700 buildings in the United States and internationally with high-activity radiological sources; and
  • Provided Alarm Response Training to more than 3,000 site security, local law enforcement officers and other first responders from across the country on responding to a potential incident involving radiological material.