Radiant Nuclear, a developer of small-scale nuclear reactors, has just closed a $300 million funding round, continuing a trend of massive investment into the nuclear energy startup space. This raise follows similar recent moves by Last Energy ($100M), X-energy ($700M), and Aalo Atomics ($100M), raising concerns about a potential investment bubble. The surge in funding directly correlates with the increasing power demands of the booming AI and data center industries.
The Growing Demand for Nuclear Energy
The current investment spike in nuclear startups isn’t accidental. Artificial intelligence, in particular, requires enormous amounts of electricity to operate. Tech companies and data center developers are aggressively seeking reliable and high-capacity energy sources, with nuclear fission emerging as a leading contender alongside other emerging technologies. If demand continues to rise, nuclear energy will remain a strong investment area. However, the sector faces scrutiny as many startups promise reactor deployment within the next year, which may not be feasible.
Radiant Nuclear’s Approach: Mobile Microreactors
Radiant Nuclear distinguishes itself by developing a compact, 1-megawatt reactor designed for transport via semi-truck. The reactor uses helium cooling and TRISO fuel—a highly durable uranium form encased in graphite and ceramic—allowing for five months of operation between refueling. The company targets replacing diesel generators at commercial and military facilities, offering both outright purchases and power-purchase agreements with a 20-year service life.
Data Centers as Key Customers
Data centers are a primary target market for Radiant. In August, the company secured a deal with Equinix to supply 20 reactors. This demonstrates the viability of nuclear energy as a solution to the high-demand, reliable energy needs of these facilities. The ability to deliver power directly to customers via mobile reactors offers a unique advantage over traditional nuclear power plants.
Regulatory Acceleration and Future Timelines
Radiant is one of 11 companies participating in a U.S. government program aimed at achieving reactor criticality by July 4, 2026—a goal set during the Trump administration. This program accelerates approval timelines but does not provide direct funding. Radiant plans to test its demonstration reactor at the Idaho National Lab starting in the summer of 2026.
The current level of investment in nuclear startups is unprecedented. While Radiant Nuclear has secured substantial funding and a clear market strategy, the long-term viability of these ventures depends on successful reactor deployment and cost-effective mass manufacturing. The next few years will determine whether these companies can deliver on their promises or fall victim to the potential “bubble” in the nuclear startup landscape.
