GTRI’s Convert Program: Minimizing the Use of Highly Enriched Uranium

Fact Sheet
Apr 12, 2013


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. As part of its mission, GTRI’s Convert Program, working domestically and internationally, implements the long-standing U.S policy to minimize and eliminate the use of highly enriched uranium (HEU) in civilian applications by working to convert research and test reactors and isotope production facilities to the use of low enriched uranium (LEU).

Taken together with NNSA’s work to prevent proliferation and secure nuclear material, the Convert Program demonstrates GTRI’s commitment to protecting the American people and the rest of the world from nuclear and radiological terrorism.


Since its inception, GTRI has accelerated its nuclear security efforts and 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 ("dirty bomb").

GTRI has converted or verified the shutdown of 88 HEU research reactors and isotope production facilities; supported the first successful large scale production of the important medical isotope molybdenum-99 (Mo-99) using LEU targets, and supported the development of a reliable, domestic supply of Mo-99 without using HEU.

Domestic Conversions & Shutdowns

In working to minimize the use of HEU and prevent terrorists from getting nuclear materials, GTRI has to date:

  • Converted all U.S. reactors capable of being converted with existing licensed LEU fuel, including reactors in Florida, Idaho, Indiana, Oregon, Texas, Washington, and Wisconsin; and
  • Working to develop a replacement LEU fuel and the associated fuel fabrication capability for the six remaining High Performance Research Reactors in the United States that cannot convert with existing fuel. 

Foreign Conversions & Shutdowns

In working to minimize the use of HEU and prevent terrorists from getting nuclear materials, GTRI has to date successfully:

  • Converted to LEU fuel 66 HEU research reactors in 34 countries, including Argentina, Australia, China, Czech Republic, Hungary, Japan, Libya, the Netherlands, Poland, Portugal, South Africa, Ukraine, Uzbekistan, and Vietnam.
  • Verified the shutdown of 22 HEU research reactors in 11 countries, including Bulgaria, Canada, Chile, China, France, Germany, India, Japan, the Netherlands, Russia, and the United Kingdom.

Isotope Production Facilities

GTRI’s Molybdenum-99 Program assists global Mo-99 producers in converting their Mo-99 production facilities from the use of HEU targets to LEU targets, and works with existing commercial entities to accelerate the establishment of non-HEU-based Mo-99 production in the United States. Since 2004, GTRI has successfully:

  • Accelerated the transition of the Mo-99 industry into a full cost-recovery model, including, calling upon the industry to voluntarily establish a unique product code or labeling for non-HEU produced Mo-99, and working with the Centers for Medicare and Medicaid Services to appropriately reimburse medical procedures that use sources of Mo-99 produced without HEU;
  • Supported South Africa’s NTP Radioisotopes in the achievement of the first large scale production of Mo-99 using LEU targets in June 2010 and delivered the first FDA-approved non-HEU-based Mo-99 for U.S. patient use in December 2010.
  • Supported the Four Party Joint Statement signed at the 2012 Nuclear Security Summit by Belgium, France, the Netherlands, and the United States stating “their determination to support conversion of European production industries to non-HEU-based processes by 2015.”
  • Verified the cessation of the use of HEU targets for isotope production in Indonesia.
  • Established partnerships with U.S. commercial entities to accelerate the development of non-HEU-based technical pathways to produce Mo-99 through cost-shared support and by providing technical support of the U.S. National Laboratories.