In 2025, nuclear and renewable power together accounted for over 80% of global electricity generation growth, up from two-thirds in 2023. The acceleration highlights a clear global shift toward low-carbon energy sources, with nuclear fission emerging as a critical pillar of that transition.
Innovation is advancing across the nuclear value chain, from next-generation reactor designs and improved fuel efficiency to safer, more sustainable waste management systems. These developments reflect growing investor confidence that nuclear technologies are moving closer to commercial reality.
This final article in our Nuclear Fission Series examines how capital is being deployed in 2025 to scale nuclear energy. Building on earlier coverage of emerging technologies, startups, and strategic partnerships, it explores where funding is flowing, who is investing, and how these trends are shaping the future of nuclear fission innovation.
Equity funding in nuclear fission hits $1.3 billion in 2025
2025 marks a defining year for nuclear fission investment. The sector recorded its highest annual venture funding to date, signaling renewed investor confidence in advanced nuclear technologies.
At the beginning of Q3 2025, nuclear fission companies have raised $1.3 billion in equity funding in 2025. This year has already accounted for close to 40% of all equity investments into nuclear fission since 2020.
Deal activity has also strengthened. The number of equity transactions rose from an average of 15 annually to 28 deals in 2025, reflecting greater capital deployment toward mature companies.
The largest round in 2025 was TerraPower’s $650 million Series C. The U.S.-based company develops advanced nuclear power plants that integrate sodium-cooled fast reactors with molten salt-based thermal energy storage to deliver flexible, carbon-free power.
Despite this momentum, total equity deals since 2020 remain around 100, emphasizing the capital-intensive nature of the sector and the persistent barriers to broader nuclear adoption.
Grants remain the second-largest funding source. Activity peaked in 2020 but has since moderated, averaging $45 million annually from 2021 onward.
Large early-stage rounds drive nuclear fission funding surge
Early-stage funding in nuclear fission rose sharply in 2025, driven by a few large transactions rather than broader startup activity. Some of the companies who received early-stage funding are US-based Aalo Atomics that builds mass-manufactured reactors and Antares which develops microreactors, to name a few.
Most technologies in development are tailored for new applications like mobile nuclear fission reactors to power data centers but have yet to reach full market validation or widespread adoption.
Late-stage investment also strengthened, led by TerraPower’s $650 million and X-Energy’s $200 million Series C rounds. These deals highlight sustained investor commitment to scaling advanced nuclear technologies nearing commercial deployment.
Pre-seed and seed rounds have remained consistent over the years but spiked in 2023 in both deal volume and count.
Global nuclear investment led by the US
The U.S. remains the predominant driver of nuclear fission, followed by select SMR developers in Europe. Over the past five years, the U.S. has raised $4.2 billion, capturing 50-60% of global nuclear fission venture funding.
Europe’s nuclear fission investment has grown from $54 million in 2020 to $188 million in 2025.
Finland and France have shown positive momentum, but investment remains concentrated in a handful of companies. Key players include Naarea, Jimmy, and Stellaria in France, and Steady Energy in Finland. The ecosystem’s growth in these regions remains closely tied to these companies’ performance.
Investments in Asia have come primarily from Japan and South Korea, which received seed funding between 2022 and 2024.
Advanced reactors dominate nuclear fission investment
Among the innovation pathways aimed at making nuclear energy scalable and low-carbon, advanced reactors attract the majority of nuclear investment. Between 2020 and 2025, advanced reactor technologies secured $3.9 billion in funding, reflecting strong investor confidence in next-generation nuclear systems.
Capital has concentrated on designs that reduce size, improve flexibility, and shorten deployment timelines. Liquid-metal-cooled reactors, high-temperature gas-cooled reactors, molten salt reactors, small modular reactors, and microreactors account for the bulk of this activity.
Nuclear waste management ranks as the second-largest segment, with more than $1 billion invested over the same period. While smaller than reactor development, the segment shows consistent funding and represents 21.2% of total nuclear investment, highlighting the importance of waste handling as reactor fleets expand.
Nuclear fission digitalisation remains a niche but emerging area. From 2020 to 2025, the segment attracted $36.5 million, growing from $0.2 million in 2020 to $3.0 million in 2025. This trend highlights rising interest in digital tools that improve reactor safety, performance monitoring, and operational efficiency.
Strategic investors begin engaging in nuclear fission
Strategic investor participation has been a key feature of 2025, with five CVCs investing in fission technology companies. These CVCs belong to major corporations such as Nvidia, Amazon, and Hitachi.
Venture capital remains the dominant investor in nuclear fission, providing the equity required to develop capital-intensive reactor technologies.
The number of active VCs has grown from three in 2020 to 46 in 2025. This sharp rise reflects investor confidence as the technology moves from lab-scale innovation to pilot projects and early commercialization. VC activity indicates where the next generation of fission startups will emerge and highlights the next wave of innovation in the sector.
Government support has been steady and continues to play a vital enabling role. While grants are often modest in value, they carry significant market validation and strengthen investor perception in a space still moving toward commercialization.
Private equity participation, however, remains minimal, with an average of two deals per year since 2020.
The path forward for investment in nuclear fission
2025 marks a turning point for nuclear fission investment. The sector has attracted record funding volumes, stronger venture participation, and early signs of commercial traction.
Investor focus has shifted toward technologies with visible deployment pathways, particularly SMRs and microreactors, that are proving their technical maturity. Participation from major corporations further reinforces that confidence is gradually building across the value chain.
However, financing remains a decisive factor in translating technical progress into real-world deployment. Forward-looking financing structures and market policies will be essential to bridge economic barriers and scale new nuclear projects.
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