Can Natrium reactors scale fast enough to meet U.S. decarbonization goals by 2040?

Backed by a $650 million funding round featuring NVentures, HD Hyundai, and Bill Gates, TerraPower’s Natrium reactor program is re-emerging at the center of U.S. nuclear innovation. With its first commercial deployment targeted for 2030 and the promise of gigawatt-scale flexible output, the Natrium platform is now facing a critical question: can it scale quickly enough to meaningfully contribute to the United States’ deep decarbonization targets by 2040?

This article evaluates whether TerraPower’s flagship technology—345 MWe sodium-cooled fast reactors coupled with molten salt thermal energy storage—can overcome regulatory, fuel, and financing barriers to help transform the U.S. electricity sector.

What regulatory and licensing milestones must be reached for Natrium reactors to accelerate deployment by 2040?

TerraPower’s Kemmerer, Wyoming project began non-nuclear construction in 2024 and submitted its Part 50 Construction Permit Application to the U.S. Nuclear Regulatory Commission, which accepted it in May 2024. This marks a major milestone—the first advanced non-light water reactor accepted into NRC review in over four decades. The company expects full permit approval by 2026, enabling nuclear construction to begin shortly thereafter.

However, replicating this model nationally before 2040 will require more than one permit. Each new site will need localized environmental reviews and reactor-specific construction licenses unless generic design certifications or Part 53 rulemaking pathways are fast-tracked. Recent executive orders signed by President Trump in 2025 have called for permitting reforms and investment incentives, but NRC timelines remain a limiting factor unless additional procedural acceleration is implemented.

Institutional investors have expressed cautious optimism that licensing bottlenecks will ease after the first demonstration plant, but regulatory scalability remains one of the most cited risks in energy transition planning models.

What financial and investment dynamics will determine whether multiple Natrium reactors can be built in time to meet 2040 targets?

The Kemmerer project is estimated to cost around $4 billion, supported by up to $2 billion in federal cost-sharing through the Department of Energy’s Advanced Reactor Demonstration Program. The remainder is being funded through private capital, including the recent $650 million round.

Analysts see TerraPower’s financing model as a strong signal of investor confidence, especially given NVentures’ participation as NVIDIA deepens its role in energy infrastructure strategy. However, scaling to dozens of Natrium units by 2040 would require tens of billions in cumulative capital across both equity and debt markets.

For institutional investors, several unknowns remain—namely around future fuel cost assumptions, operational efficiency, and public acceptance. Natrium’s modularity and ability to reuse brownfield coal plant infrastructure provide some cost advantages, but capital intensity and long return horizons are still challenges in the current investment climate.

How critical is domestic HALEU supply to scaling Natrium reactors before 2040?

The most widely cited bottleneck in advanced reactor deployment is fuel availability. Natrium reactors require high-assay low-enriched uranium (HALEU), enriched to between 5% and 20% U-235—above the level used in existing light water reactors.

Until 2022, Russia was the dominant commercial supplier of HALEU. After geopolitical tensions disrupted those flows, U.S. developers have been reliant on early-stage government-supported enrichment efforts. Centrus Energy has begun pilot production in Ohio, and TerraPower has signed a non-binding agreement with ASP Isotopes to build a commercial-scale enrichment facility. However, full-scale HALEU availability is not expected until late this decade.

The lack of fuel was one of the reasons TerraPower delayed its Kemmerer launch timeline from 2028 to 2030. Without robust domestic HALEU supply chains, further Natrium builds would be impossible—even with regulatory and financing momentum. For Natrium to contribute to decarbonization targets by 2040, HALEU must become a stable, predictable input by 2026–2027 at the latest.

What infrastructure and supply-chain challenges must be resolved to see Natrium reactors operating at scale by 2040?

Construction of advanced reactors requires specialized fabrication capabilities—many of which have eroded since the last wave of U.S. nuclear builds. Sodium handling equipment, modular reactor vessels, and heat exchangers are not manufactured at commercial scale within the U.S. today.

To meet 2040 targets, a domestic industrial base must be re-established, including certified component suppliers and advanced welding, casting, and fuel fabrication capacity. TerraPower’s approach—deploying at brownfield coal plant sites—does mitigate some of the grid interconnection and labor issues, but long-lead-time components and skilled labor remain thinly stretched.

The Department of Energy has initiated several programs to rebuild supply chains, but coordination between utilities, component makers, and regulators will be essential. Without early procurement and workforce training programs starting by 2026, a supply-driven deployment bottleneck is almost certain.

How do Natrium reactors complement renewable energy sources to provide a balanced low-carbon electricity portfolio by 2040?

The Natrium system is designed for flexible operation. It combines a constant-output sodium-cooled reactor with a molten salt thermal energy storage system that allows up to 500 MWe of peaking capacity. This enables the plant to ramp up output during evening hours or low-wind periods—providing firm dispatchable capacity in high-renewables grids.

This capability is critical. By 2040, multiple U.S. states (e.g., California, New York, Illinois) aim to be sourcing 80–90% of electricity from carbon-free sources. Intermittent generation from wind and solar cannot provide the round-the-clock reliability needed without support from storage or nuclear firming capacity.

Grid models from system operators like CAISO and MISO increasingly include small modular and advanced reactors in 2040 resource planning. The hybrid design of Natrium gives it an edge over traditional baseload reactors, aligning well with decarbonization roadmaps that prioritize flexible, low-emission generation.

What is the investor and institutional sentiment around advanced nuclear’s impact on 2040 decarbonization timelines?

Investor sentiment is cautiously constructive. TerraPower’s institutional backing—ranging from HD Hyundai to NVIDIA’s NVentures—demonstrates a diverse and increasingly technology-aligned capital base. Breakthrough Energy’s long-term involvement continues to support political visibility and international expansion ambitions.

However, institutional investors still flag multi-reactor scalability, fuel risk, and cost containment as top concerns. Many are in a “watch and wait” phase until the Kemmerer build reaches late-stage construction or licensing approval.

That said, there is a general recognition across the clean energy investing space that advanced nuclear is no longer an academic experiment. It is increasingly viewed as a necessary complement to renewables in achieving grid reliability and decarbonization.

What policy and market developments are needed to enable Natrium reactors to become mainstream by 2040?

For Natrium reactors to reach deployment scale by 2040, three categories of policy support are essential: expedited licensing, fuel security, and revenue predictability.

On licensing, faster NRC approval paths—either through Part 53 or generic design certifications—will be critical. On fuel, a national HALEU strategy with commercial enrichment and public procurement commitments must be executed. On financing, stable market mechanisms such as power purchase agreements (PPAs), clean energy credits, or capacity payments are needed to de-risk capital-intensive builds.

The 2022 Inflation Reduction Act and the 2023 ADVANCE Act created important foundations, but additional rulemaking, funding, and grid-market integration reforms will likely be required by 2027 to meet a 2040 deployment window.

TerraPower’s Natrium reactor represents one of the most commercially advanced designs in the next-generation nuclear field. While its technical merits, policy backing, and investor confidence suggest momentum is building, real-world deployment at the scale required to impact 2040 decarbonization goals depends on resolving interlinked challenges in regulation, fuel availability, financing, and supply chain readiness. If those conditions are met, Natrium could become a foundational asset in the clean energy transition.