Bill Gates-Backed 345 MWe Advanced Nuclear Reactor Secures Crucial US Approval

TerraPower’s 345 MWe Natrium reactor—a next-generation advanced nuclear system backed by Bill Gates—has cleared a critical regulatory hurdle in the United States. The U.S. Department of Energy (DOE) has completed its environmental review under the National Environmental Policy Act (NEPA), paving the way for construction to begin in Wyoming as early as 2024. This milestone marks a significant step toward deploying advanced reactors that could reshape both civilian and military baseload energy strategies.

What Is the Natrium Reactor?

The Natrium reactor is a sodium-cooled fast reactor (SFR) developed by TerraPower in partnership with GE Hitachi Nuclear Energy. Rated at 345 megawatts electric (MWe), it leverages liquid sodium as a coolant instead of water—allowing higher operating temperatures and passive safety features without pressurization risks.

Key technical features include:

• Sodium coolant enabling operation at ~500–550°C without high pressure
• Molten salt-based thermal energy storage that can boost peak output to ~500 MWe for short durations
• Passive safety systems that rely on natural convection and thermal expansion to shut down safely without active intervention
• Compact footprint, potentially reducing siting costs and improving deployment timelines

This design is considered part of the Generation IV class of reactors—systems aimed at improving sustainability, safety, fuel efficiency, and proliferation resistance compared to traditional light-water reactors.

DOE Environmental Approval Clears Construction Path in Wyoming

The DOE’s Final Environmental Impact Statement (EIS), published in October 2023, concluded that the proposed Kemmerer, Wyoming site poses no significant environmental risks that would preclude construction. The review covered seismic stability, water usage (which is minimal due to sodium cooling), ecological impacts, and socio-economic factors.

This approval allows TerraPower to proceed with site preparation activities while awaiting further licensing from the U.S. Nuclear Regulatory Commission (NRC). The company aims to begin construction in mid-2024 with commissioning targeted for late this decade—though delays are possible due to fuel supply constraints.

High-Assay Low-Enriched Uranium (HALEU): A Bottleneck?

A critical dependency for the Natrium project is access to High-Assay Low-Enriched Uranium (HALEU)—uranium enriched between 5% and 20% U-235. HALEU offers better neutron economy for fast-spectrum reactors but is not yet commercially produced at scale in the United States.

The U.S. currently relies on Russian supply chains for HALEU—a strategic vulnerability exacerbated by geopolitical tensions following Russia’s invasion of Ukraine. While DOE has initiated programs to stimulate domestic HALEU production via Centrus Energy and others, timelines remain uncertain.

If domestic HALEU production does not ramp up by mid-decade, TerraPower may face delays despite regulatory readiness. The company has acknowledged this risk publicly and is lobbying alongside other advanced reactor developers for accelerated federal investment in enrichment capacity.

DOD Interest: Military Applications of Advanced Reactors

The Pentagon has shown growing interest in small modular reactors (SMRs) like Natrium for forward-deployed baseload power or resilient grid-independent installations on military bases. While TerraPower’s current deployment plan is civilian-focused, its modularity and passive safety architecture make it attractive for expeditionary or austere environments where diesel logistics are vulnerable or costly.

The Department of Defense’s Project Pele—a mobile microreactor program led by the Strategic Capabilities Office—shares similar goals but targets smaller outputs (~1–5 MWe). However, lessons from larger designs like Natrium could inform future scalable solutions for theater-level logistics hubs or hardened command centers requiring uninterrupted power under cyber/kinetic threat conditions.

Strategic Implications: Civil-Military Energy Convergence & Industrial Base Revitalization

The advancement of next-gen nuclear technologies like Natrium intersects with broader strategic objectives:

• Energy resilience: Reducing dependence on fossil fuels across both civilian grids and defense infrastructure
• Nuclear industrial base revival: Rebuilding domestic capabilities across enrichment, fuel fabrication, component manufacturing
• Export competitiveness: Positioning U.S.-backed designs against Chinese HTR-PM and Russian RITM/BN-class exports in emerging markets
• Dissuading adversaries: Demonstrating technological leadership in clean baseload generation with dual-use potential can serve soft power objectives vis-à-vis China/Russia influence campaigns around nuclear tech diplomacy

Next Steps & Outlook Through Late Decade

If construction proceeds on schedule starting mid-2024—and assuming HALEU supply issues are resolved—the first operational deployment of a commercial-scale sodium fast reactor could occur before the end of this decade. This would mark a historic milestone not only for TerraPower but also for Generation IV fission technology globally.

The coming years will be shaped by several key milestones:

• NRC licensing process completion (~2025)
• Civil works initiation at Kemmerer site (~mid-2024)
• Status updates on DOE-funded HALEU enrichment projects (~2024–25)

If successful, follow-on deployments could expand across both utility-scale grids and defense installations seeking hardened energy independence amid rising peer-threat competition scenarios where logistics denial is increasingly probable.