NSI Maps Bottlenecks Facing the U.S. Advanced Nuclear Energy Supply Chain and Identifies Solutions in New Report

A new report from the Nuclear Scaling Initiative (NSI), Landscape of U.S. Domestic Advanced Nuclear Energy Supply Chain, released with support from the Bezos Earth Fund, identifies solutions and coordinated strategies to assist in scaling the deployment of advanced nuclear energy and overcome bottlenecks in the supply chain. As policymakers and industry leaders seek to expand advanced reactor capacity to meet rising electricity demand and strengthen energy security, the report finds that a self-reinforcing cycle of market paralysis — in which suppliers hesitate to invest without firm demand signals and buyers hesitate to commit without supply chain certainty — is suppressing manufacturing expansion, fuel supply, and workforce growth.   

The report, commissioned by NSI and prepared by energy consultancy Solestiss, is part of a broader effort to accelerate the deployment of advanced nuclear energy in the United States by strengthening supply chains, improving procurement transparency, and enabling more coordinated investment across the nuclear ecosystem. 

“As this report makes clear, advanced nuclear energy will not scale if suppliers and buyers continue to treat investment risk like it’s someone else’s problem,” said Steve Comello, executive director of NSI. “But solutions are within reach. When buyers come together around durable, multi-unit reactor orderbooks, capital can begin to move with confidence — and that confidence translates into more factories, trained workers, qualified suppliers, and gigawatts on the grid. By aligning demand signals with workforce development, we can unlock a repeatable model for building nuclear energy at scale.” 

“The Bezos Earth Fund supports strategies and solutions to accelerate clean power that are not only low carbon, but also reliable, affordable and buildable at scale,” said Nicole Iseppi, director of energy innovation at the Bezos Earth Fund. “Meeting rising electricity demand while reducing emissions will require large-scale invention and collaboration. This report helps to clarify what it will take to strengthen the U.S. domestic nuclear supply chain so advanced nuclear reactors can move from invention to scalable execution. That is critical for climate, for energy security, and for building a cleaner grid with a small land footprint. We’re proud to support NSI’s latest research.” 

The analysis examines key segments of the domestic supply chain for large light-water reactors, small modular reactors (Gen III+ and Gen IV), and microreactors across three core areas: fuel supply; systems, structures, and components; and the skilled workforce required to build and operate plants. 

Key findings include: 

• Fuel supply constraints are structural and sequential: The low-enriched uranium supply chain is technically mature but has limited capacity, and aggressive deployment could create bottlenecks. For high-assay low-enriched uranium (HALEU), the United States lacks commercial-scale enrichment, deconversion, certified transport, and fabrication capacity. Plutonium-bearing fuels raise considerable infrastructure and security concerns that neutralize their viability for scaling for the foreseeable future. 

• Manufacturing bottlenecks are increasingly downstream: Constraints lie in machining, welding, finishing, inspection, and non-destructive examination. These specialized manufacturing steps require nuclear-qualified facilities and highly trained workers, and are difficult to sequence. The result is that throughput — not just factory count — governs scale. 

• Labor shortages extend beyond construction trades: Workforce gaps include nuclear-qualified machinists, welders, inspectors, non-destructive examination specialists, and experienced project managers. These roles take years to train and compete with other industrial megaprojects, creating schedule and execution risks across reactor builds. 

“The U.S. advanced nuclear supply chain is caught up in a complex geopolitical landscape,” said Dillon Allen, president at Solestiss. “Current supply chains rely heavily on Russia and China for lithium-7, nuclear-grade graphite, and uranium conversion and enrichment. Downstream manufacturing bottlenecks and a shortage of skilled nuclear labor only add to that risk, meaning that without coordinated investment and workforce development, the United States may struggle to deploy nuclear energy at the scale needed to meet long-term energy demand.”  

To break the cycle of market paralysis, the report outlines a series of interconnected recommendations for stakeholders across the nuclear ecosystem to reduce uncertainty, unlock investment, and accelerate supply chain scale-up: 

• Federal government: Provide durable policy clarity, accelerate deployment of appropriated funding with clear down-selections, aggregate or backstop early demand, and act selectively as a market-maker for HALEU. 

• Regulators and standards organizations: Expand and formalize alternative quality assurance pathways and enable repeatable approvals for validated manufacturing methods. 

• Industry (engineering, procurement, and construction firms; original equipment manufacturers; and suppliers): Address downstream bottlenecks by strengthening machining, welding, and inspection capacity; embedding design-for-manufacturability early; and standardizing designs to reduce fragmentation. 

• Utilities, offtakers, and capital providers: Close bankability gaps by converting expressions of interest into firm, long-duration commitments; supporting fleet-style procurement models and standardized commercial structures; and aligning contracting strategies with supply chain and workforce realities. 

• Workforce and training institutions: Scale skilled labor pipelines — particularly in manufacturing, inspection, and project management — in alignment with realistic deployment sequencing and verified manufacturing demand to prevent timing mismatches that could delay projects. 

NSI and Solestiss experts will share more about report’s findings at a public webinar on April 21 at 11:00am ET. Read the full report here. 

Press Contact 

Natalie Volk, Communications Manager, Clean Air Task Force, [email protected] (+1 703-785-9580) 

About NSI  

NSI is a collaborative effort of Clean Air Task Force, the EFI Foundation, and the Nuclear Threat Initiative to build a new nuclear energy ecosystem that can quickly and economically scale to 50+ gigawatts of safe and secure nuclear energy globally per year by the 2030s. 

Learn more at www.nuclearscaling.org 

NSI’s work on the U.S. supply chain is made possible by the support of the Bezos Earth Fund.