Pillar 3
Action 61
Encourage States concerned, on a voluntary basis, to further minimize highly enriched uranium in civilian stocks and use, where technically and economically feasible.
French operators (CEA, Framatome) are part of the Heracles EU-funded consortium to develop alternative technologies to highly-enriched uranium. The consortium developed in particular H2020 project such as the Heracles-CP (development on sound scientific understanding of the irradiation behaviour of UMo and advancing production techniques for dispersion fuel) from 2015 to 2019, LEU FOREvER (advancing production technology for dispersion and monolithic fuels and paving the way for high density U3Si2 fuels) from 2017 to 2021 and the EU-Qualify (research on medical isotopes) from 2020 to 2026.
Framatome has started cooperation with the Technical University of Munich in 2019 for the conversion of the FRM II reactor to low enriched uranium.
French operators (CEA, Framatome, Institut Max Von Laue, Institut Polytechnique de Grenoble) have completed the EU-funded project EU-Qualify from 2020 to 2026. In 2024, the US NNSA and Kyoto University (Japan) announced that the French company Framatome CERCA had taken part in converting the Kyoto University Critical Assembly’s “Core C” to use HALEU fuel instead of highly enriched uranium.
During the current Review Cycle, the conversion of the FRM II reactor in Germany has moved forward with the support of the EU-CONVERSION programme (adopted in February 2025) and the cooperation of Framatome, Institut Laue-Langevin, the CEA and the Université Grenoble Alpes.
Converting the Kyoto University Critical Assembly’s “Core C” to use HALEU fuel marks over a decade of U.S.-Japan collaboration, NNSA, 19 November 2024, https://www.energy.gov/nnsa/articles/nnsa-converts-its-110th-research-reactor-following-decade-long-effort-japan
Website of the Heracles Consortium, https://heracles-consortium.eu/horizon2020.php
Supplying the European Research Reactors with Safe Low-Enriched Uranium Fuels for Their Conversion and Long-Term Operation to Secure the Supply of Medical Radioisotopes, CORDIS, 2024, https://cordis.europa.eu/project/id/101163752/fr
Russia participated in international efforts aimed at minimizing the use of highly enriched uranium in nuclear fuel for research reactors where it is technically feasible and economically justified.
Under the Agreement between Russia and the United States Concerning the Disposition of Highly Enriched Uranium Extracted from Nuclear Weapons (the HEU-LEU Agreement), 500 tonnes of weapons-grade highly enriched uranium were downblended and reprocessed into low enriched uranium.
Russia conducted feasibility studies on the conversion of six Russian research reactors from highly enriched uranium to low enriched uranium fuel under a 2010 agreement with the United States. In 2014, Russia completed the conversion of one research reactor.
From 2004 to 2016, Russia repatriated Russian-origin highly enriched uranium (HEU) fuel from 14 countries under the Russian Research Reactor Fuel Return (RRRFR) Program
Russia has not communicated on further implementation of this action in the current review cycle
Agreement between the Government of the Russian Federation and the Government of the United States of America Concerning the Disposition of Highly Enriched Uranium Extracted from Nuclear Weapons, 1993.
https://fissilematerials.org/library/heu93b.pdf
National report of the Russian Federation for the 2015 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (New York), 21 May 2015.
https://www.un.org/en/conf/npt/2015/pdf/NPT-CONF2015-48_National%20report%20of%20the%20Russian%20Fed_E.pdf
The Nuclear Decommissioning Authority and the US Department of Energy's National Nuclear Security Administration completed the transfer of around 700kg of HEU from the UK’s Dounreay site to the US in 2019. This was publicly announced as a non-proliferation commitment and is the most significant UK civilian HEU minimisation action of the prior cycle.
The United Kingdom states that it has reduced its holdings of Highly Enriched Uranium (uranium enriched to 20% or higher – Highly Enriched Uranium) since 2017 from 1214kg to 637kg in 2024.
The UK also committed in 2026 that all civil nuclear reactors in the UK are to be fuelled by uranium enriched to less than 20% U-235.
Nuclear Decommissioning Authority (2019). US and UK complete project to remove highly enriched uranium. 3 May. https://www.gov.uk/government/news/us-and-uk-complete-project-to-remove-highly-enriched-uranium.
Foreign, Commonwealth and Development Office (2026). National report of the United Kingdom of Great Britain and Northern Ireland pursuant to actions 5, 20 and 21 of the action plan of the 2010 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons for the eleventh Review Conference of the Parties to the Treaty. <https://assets.publishing.service.gov.uk/media/69df600a53469bbcdf408e8b/UK-National-Report-11th-Treaty-on-the-Non-Proliferation-of-Nuclear-Weapons-NPT-Review-Conference.pdf>
Department for Energy Security & Net Zero (2026). Statement on civil nuclear fuel use. 4 February. https://www.gov.uk/government/publications/civil-nuclear-fuel-use-statement/statement-on-civil-nuclear-fuel-use.
In 1978, the Department of Energy established the Reduced Enrichment for Research and Test Reactors (RERTR) program to help minimize civilian use of highly enriched uranium. The U.S. Government’s Global Threat Reduction Initiative and subsequent 2016 reorganization into the NNSA’s Office of Material Management and Minimization continued these efforts. Since 1978, at least 109 research reactors and medical isotope facilities worldwide were either converted to LEU or confirmed shutdown.
Prior to the current Review Cycle, the NNSA also achieved success in helping Mo-99 production facilities in converting to high-assay low-enriched uranium (HALEU) and supports the establishment of domestic supplies of Mo-99 without the use of proliferation-sensitive HEU. The NNSA’s progress on this issue prompted a joint certification in 2021 by the Secretaries of Energy and Health and Human Services that there was now enough worldwide supply of the medical isotope molybdenum-99 made without using HEU to meet the needs of patients in the United States, thus triggering a congressionally mandated ban on exports of HEU for foreign medical isotope production.
During the current Review Cycle, the NNSA’s Office of Material Management and Minimization developed, designed, and tested a new LEU fuel (uranium-molybdenum monolithic) that as of 2026 was in the final stages of fuel demonstrations before applying for regulatory approval for use. In addition to this new first of a kind monolithic fuel, M3 has partnered with the European HERACLES consortium of reactors and fuel manufacturers to develop, design, test, and qualify new high-density LEU fuels including a new uranium-molybdenum dispersion fuel, as well as a higher-density uranium-silicide dispersion fuel. These new LEU fuels will be used to convert research reactors in the United States and abroad.
In addition, in 2023, the NNSA’s Mo-99 Program achieved a major milestone when it helped Belgium’s National Institute of Radioelements convert their medical isotope production facility from HEU to LEU; as a result, all major global molybdenum-99 (Mo-99) production facilities now use LEU targets.
U.S. Department of Energy. “RERTR-2024 International Meeting.” October 27-31, 2024. https://rertr.nse.anl.gov/international-meetings/2024-meeting/.
U.S. Department of Energy. “Qualification of New LEU Fuels for Research Reactors.” April 23, 2026. https://www.energy.gov/nnsa/qualification-new-leu-fuels-research-reactors.
U.S. Department of Energy. “U.S. Secretaries of Energy and Health and Human Services Jointly Certify Sufficient Worldwide Supply of Critical Medical Isotope.” December 20, 2021. https://www.energy.gov/articles/us-secretaries-energy-and-health-and-human-services-jointly-certify-sufficient-worldwide.
U.S. Department of Energy. “NNSA helps global health industry achieve major nuclear nonproliferation milestone.” March 28, 2023. https://www.energy.gov/nnsa/articles/nnsa-helps-global-health-industry-achieve-major-nuclear-nonproliferation-milestone.