Why HALEU Is the Missing Link for Advanced Reactors
Advanced reactors need HALEU enriched to 5-20% U-235, but the U.S. has no commercial HALEU source; DOE-backed projects aim to close the gap by 2029.
Advanced reactors and SMR programs consuming HALEU — TerraPower, X-energy, Kairos, Oklo and fleet demand
Advanced reactors need HALEU enriched to 5-20% U-235, but the U.S. has no commercial HALEU source; DOE-backed projects aim to close the gap by 2029.
The U.S. Department of Energy has approved the Nuclear Safety Design Agreement for Antares's Mark-1 microreactor, as the company lines up HALEU from both Centrus and Urenco for its deployment pipeline.
TerraPower signed a separate enrichment agreement with a South African company over doubts that DOE can supply enough HALEU in time for its first reactor, as SMRs and microreactors drive demand.
TerraPower's Natrium delay, Google's 500 MW Kairos deal and Amazon's backing of X-energy's 5 GW target show how HALEU availability now governs advanced reactor schedules and hyperscaler procurement.
Amazon, American Electric Power and X-energy have agreed to explore a 960-MW, 12-unit Xe-100 project at a former coal plant in Sullivan County, Indiana — a potential anchor for HALEU and TRISO fuel demand in the US Midwest.
DOE approved the Nuclear Safety Design Agreement for Antares' Mark-1 microreactor on 23 October 2026, as the company assembles HALEU supply deals with Urenco, General Matter and Centrus plus a multi-year TRISO contract with Standard Nuclear.
TerraPower's $4 billion Natrium reactor in Wyoming requires HALEU enriched to about 19% U-235, and losing access to Russian supply after 2022 pushed the project back at least two years — even as Centrus restarts domestic production at Piketon, Ohio.
Surging electricity demand from AI data centres, robotics and advanced manufacturing is reviving nuclear interest, but many SMR designs depend on HALEU that the US does not yet produce at scale.
Centrus was expected to reach 1.8 MTU of HALEU by the end of June 2026 — less than 10% of estimated demand — while Natrium's construction permit and 2030 target put pressure on fuel timelines.
A 2026–2031 global enrichment outlook warns that HALEU production plans fall short of what a large advanced reactor fleet would need, even as SMR and microreactor developers sign multi-year fuel offtakes.
Reactor developers like Radiant and Thorizon are securing long-term HALEU supply agreements and launching fuel qualification programs to advance microreactor and molten salt reactor deployments.
Advanced reactor developer Oklo has announced plans for its Groves-2 project and secured a spot in the DOE's Nuclear Energy Launch Pad program. The company continues to expand its HALEU-powered reactor footprint despite recent interconnection queue challenges.