In January 2025, NNSA Administrator Jill Hruby posted the following as a letter in Science, in response to the June 2024 article titled “The weapons potential of high-assay low-enriched uranium.”
National Nuclear Security Administration
January 6, 2025
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On Jan. 2, 2025, NNSA Administrator Jill Hruby posted the following as an e-letter in Science, in response to the June 2024 article titled “The weapons potential of high-assay low-enriched uranium.” You can find the original article and Administrator Hruby’s e-letter here.
In June 2024, Science published “The weapons potential of high-assay low-enriched uranium” by Kemp, Lyman, Deiner, Garwin, and von Hippel. In September, an open letter from the American Nuclear Society rebutted the article’s concerns, and in November, the Science authors responded in Nuclear News. All articles recommend the National Nuclear Security Administration (NNSA) conduct a risk evaluation on the potential for HALEU-based reactors to increase nuclear weapons proliferation.
Given concerns about climate change coupled with increased energy demand, nuclear energy is poised for growth. Advanced and small modular reactors (A/SMRs) using HALEU fuel are under active development. NNSA recognizes that reactor type, fuel enrichment level, fuel quantity, and fuel form are important factors in evaluating proliferation risks and believes that risk-informed and adaptive approaches to the proliferation challenges inherent in nuclear energy are warranted.
It is important that U.S. A/SMR designs compete favorably in the global market and set high standards for safety, security, and safeguards, especially considering Russia’s takeover of Ukraine’s largest nuclear power plant. NNSA has a program to support U.S. A/SMR developers on security- and safeguards-by-design and promotes best practices for nuclear energy deployment by partnering with the International Atomic Energy Agency (IAEA).
With its national laboratories, NNSA has regularly collected data1 and evaluated HALEU risks, and is currently finalizing plans to commission a National Academies report. Although these reports are largely classified, the information is used to inform programs, develop actions, and make recommendations to stakeholders.
It is important to address proliferation concerns about HALEU and important to responsibly develop A/SMRs. NNSA commits to working with academia, industry, the public, and IAEA to do just that.
1 For example, Los Alamos recently conducted a critical experiment of TRISO fuel at the National Criticality Experiments Research Center in Nevada.