TerraPower Leads Sodium Coolant Race
Zap Energy
This puts Zap into a market where the hardest early work is no longer reactor physics, it is proving to regulators and suppliers that a new sodium system can actually get built. TerraPower now has an NRC issued construction permit for Natrium in Wyoming, which means sodium handling, component qualification, and site level safety review are already moving from paper into field execution. Zap, by contrast, has described a sodium cooled ZMR concept but has not publicly laid out the matching fuel plan, licensing path, or deployment schedule.
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TerraPower is ahead in the part of nuclear commercialization that creates real barriers, not just drawings. The NRC authorized construction of Kemmerer Power Station Unit 1 on March 4, 2026, and NRC advanced reactor records list the permit as issued in March 2026. That gives TerraPower a head start with sodium equipment vendors, operating procedures, and regulator familiarity.
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Oklo is further along than Zap on licensing engagement for distributed fast reactors. NRC records show active pre application work for Aurora, including a 2025 meeting on pre construction activities, and Oklo says it completed an NRC readiness assessment for its next combined license filing. That matters because data center buyers want a project that looks licensable on a calendar, not just promising in a lab.
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Westinghouse competes from the opposite direction, with a smaller microreactor and a large nuclear services base already in place. eVinci is marketed for remote and resilient power applications, and Westinghouse ties it to decades of engineering and service capability. That makes the sales pitch less about breakthrough science and more about delivering a packaged power unit customers believe can be maintained for years.
The next phase of advanced fission will reward teams that can turn design choices into licensed projects, qualified supply chains, and repeatable customer deployments. If Zap wants ZMR to become a credible bridge from fission to fusion, it will need to look less like a concept extension of its fusion work and more like a fully specified nuclear product that can survive the same regulatory gauntlet TerraPower, Oklo, and Westinghouse are already navigating.