In 2025, the Department of Energy (DOE) used targeted programs to reduce two of the biggest bottlenecks in advanced nuclear commercialization: fuel availability and paths to faster testing/authorization. This short note organizes the DOE-identified company lists from two separate efforts, one focused on HALEU access, the other on reactor testing deployment pathways, so the signal is easy to read.
These programs are complementary but not interchangeable: a HALEU conditional commitment is fundamentally a fuel-access action, while a Reactor Pilot Program selection is a testing/authorization action.
1) HALEU Availability Program (Conditional commitments for first HALEU allocations)
1. TRISO-X, LLC
Overview: TRISO-X is X-energy’s TRISO fuel product and associated manufacturing effort focused on producing coated fuel particles for advanced nuclear reactors. The way X-energy presents it, the fuel’s coated particle design is a core safety and performance feature, and TRISO-X is meant to provide a reliable domestic supply of that fuel form.
Focus: TRISO-X is focused on manufacturing TRISO fuel at commercial scale for advanced reactor developers, including fuel that requires HALEU. The emphasis is on fuel integrity at high temperatures, consistent quality, and building fuel supply capacity that supports advanced reactor deployment.
Financial backers: X-energy has publicly announced major backing including a large financing led by Jane Street and support from Amazon’s Climate Pledge Fund.
2. Kairos Power, LLC
Overview: Kairos Power is an engineering-led advanced nuclear company focused on developing and commercializing its reactor technology through integrated design, licensing, and demonstration work. The company frames its mission around enabling clean energy while improving affordability and safety.
Focus: Kairos Power is focused on advancing its reactor platform toward a U.S. demonstration and scaling pathway, with a heavy emphasis on reducing technical and program risk through iterative testing and a licensing-first approach. In practical terms, the focus is building the technical and regulatory foundation to deploy its reactor design at commercial scale.
3. Radiant Industries, Inc.
Overview: Radiant is developing a portable nuclear microreactor product aimed at delivering reliable power where logistics and resiliency matter, especially in remote or infrastructure-constrained environments. The company positions its first reactor, Kaleidos, as a small, transportable unit designed for standardized manufacturing and deployment.
Focus: Radiant’s focus is on commercializing a factory-built, portable microreactor that can be deployed for off-grid and backup use cases, with a product approach centered on repeatability, transportability, and simplified operations. The emphasis is on providing dependable power as an alternative to diesel generation for certain high-need customers and locations.
Financial backers: Radiant has publicly announced venture funding through a Series C, with Giant Ventures named among the investors.
4. Westinghouse Electric Company, LLC
Overview: Westinghouse Electric Company is a major global supplier of nuclear technology and services focused on safe, reliable nuclear power generation. The company positions itself as a provider not only of nuclear power plant technology, but also nuclear fuel, plant automation, and a broad set of operating plant products and services that support utilities worldwide.
Focus: Westinghouse’s focus is on end-to-end support for the nuclear fleet and new builds, with an emphasis on helping utility customers keep plants safe, reliable, and efficient. Practically, that spans reactor and plant technologies, fuel supply, modernization and instrumentation and controls, and ongoing services that improve performance and extend operating life.
Financial backers (ownership): Westinghouse is owned by Brookfield (with institutional partners) and Cameco, which matters because it ties the company to large pools of infrastructure capital and to the fuel cycle through Cameco.
5. TerraPower, LLC
Overview: TerraPower is a nuclear innovation company working to develop technologies that deliver safe, affordable, abundant carbon-free energy. In addition to power generation, TerraPower describes efforts that apply nuclear science to broader outcomes, including using heat and electricity to support industrial decarbonization and developing processes to extract radioisotopes for medical uses. The company was founded by Bill Gates and other partners to accelerate private-sector development of advanced nuclear energy.
Focus: TerraPower’s focus is on advanced nuclear reactor development and related nuclear technology applications, with the aim of scaling clean energy production and enabling decarbonization. Alongside reactor innovation, TerraPower highlights work that translates nuclear capabilities into industrial heat and medical isotope production, positioning the company across both power and adjacent nuclear-enabled markets.
Financial backers: TerraPower has publicly announced major backing that includes Bill Gates and strategic and corporate investors such as HD Hyundai and NVentures (NVIDIA’s venture arm).
2) Nuclear Reactor Pilot Program (Initial selections / advanced reactor projects)
1. Aalo Atomics Inc.
Overview: Aalo Atomics describes itself as building mass-manufactured nuclear plants designed to power a wide range of loads, from a single data center to a large city. The positioning emphasizes scalable, repeatable manufacturing as the core way to make nuclear deployment faster and more broadly available.
Focus: Aalo’s focus is on standardized, factory-oriented nuclear plant production that can be deployed in different configurations depending on customer demand. The message is about scaling supply through manufacturing discipline rather than one-off builds, with an implicit emphasis on serving large power demand growth nodes like data centers as well as broader grid needs.
Financial backers: Aalo has publicly announced a $100 million Series B led by Valor Equity Partners, with participation from a mix of venture and strategic investors including Fine Structure Ventures, Hitachi Ventures, Crosscut, NRG Energy, Kindred Ventures, and 50Y.
2. Antares Nuclear Inc.
Overview: Antares positions itself as a microreactor company focused on delivering reliable, mobile energy in places where delivering power is difficult. The company frames its mission around enabling “energy abundance” that supports national security, industrial activity, and future missions beyond Earth, with microreactors as the enabling hardware.
Focus: Antares is focused on compact nuclear microreactors for high-need, hard-to-serve environments such as remote military bases and austere industrial sites, with longer-term ambition extending to deep space and underwater missions. The emphasis is on shipping real hardware and operating in constrained environments, rather than purely theoretical designs.
Financial backers: Antares has publicly announced a $96 million Series B led by Shine Capital, with participation from a group including Alt Capital, Caffeinated Capital, FiftyThree Stations, Industrious Ventures, and other investors.
3. Atomic Alchemy Inc.
Overview: Atomic Alchemy is focused on radioisotopes, with a mission to become a reliable supplier of radioisotopes for medical, research, exploration, and industrial use. The company’s framing highlights fixing a supply chain it views as constrained or broken and creating more abundant, dependable isotope availability.
Focus: Atomic Alchemy’s focus is radioisotope production at higher reliability and scale, aimed at downstream uses in healthcare and broader industry. The core idea is to expand and stabilize isotope supply so end users are less exposed to shortages and disruptions.
Financial backers: N/A
4. Deep Fission Inc.
Overview: Deep Fission positions itself as “powering humanity from a mile underground” and describes a concept built around placing small modular reactors (SMRs) about a mile underground to enable cheaper, faster, and more scalable deployment. The framing emphasizes a redesigned deployment model, with the underground siting approach as the differentiator.
Focus: Deep Fission’s focus is on developing an SMR deployment approach that uses deep underground placement to reduce cost, accelerate build timelines, and improve scalability. In plain terms, the company is centered on “where and how” reactors get deployed as much as the reactor itself.
Financial backers: Deep Fission has publicly disclosed venture backing that includes 8VC (among others), as part of its financing announcements.
5. Last Energy Inc.
Overview: Last Energy describes itself as a full-service developer of micro modular nuclear power plants with a mission to decarbonize global energy production and expand access to clean, affordable power. The company’s stated goal is to scale nuclear by materially reducing construction time and cost.
Focus: Last Energy’s focus is on developing and delivering micro modular nuclear plants using a model that prioritizes faster delivery and lower construction cost. The emphasis is on commercialization mechanics and project delivery, aiming to make nuclear easier to replicate across many sites.
Financial backers: N/A
6. Oklo Inc.
Overview: Oklo states its mission is to provide clean, reliable, affordable energy through deploying next-generation fast fission technology while also recycling nuclear waste. The positioning centers on “always on” clean power paired with a waste-recycling thesis.
Focus: Oklo’s focus is on commercializing fast fission power systems and pairing deployment with a narrative of improved fuel utilization through recycling nuclear waste. The company is oriented around delivering firm clean power with a differentiated technology pathway and fuel-cycle angle.
Financial backers: Oklo is publicly associated with backing from Sam Altman and has had substantial market visibility through its public-company path.
7. Natura Resources LLC
Overview: Natura Resources describes its mission as meeting rising demand for reliable energy, medical isotopes, and clean water by developing commercially deployable molten salt reactors. It also highlights the creation of the Nuclear Energy eXperimental Testing Research Alliance (NEXTRA) with a consortium of universities to design, build, and license a molten salt research reactor.
Focus: Natura’s focus is on molten salt reactor deployment and on enabling near-term demonstration through research-reactor development and partnerships with academic institutions. The company frames its end markets broadly, spanning power, isotope production, and desalination or clean water applications.
Financial backers: N/A
8. Radiant Industries Inc.
Overview: Radiant is developing a portable nuclear microreactor product aimed at delivering reliable power where logistics and resiliency matter, especially in remote or infrastructure-constrained environments. The company positions its first reactor, Kaleidos, as a small, transportable unit designed for standardized manufacturing and deployment.
Focus: Radiant’s focus is on commercializing a factory-built, portable microreactor that can be deployed for off-grid and backup use cases, with a product approach centered on repeatability, transportability, and simplified operations. The emphasis is on providing dependable power as an alternative to diesel generation for certain high-need customers and locations.
Financial backers: Radiant has publicly announced venture funding through a Series C, with Giant Ventures named among the investors.
9. Terrestrial Energy Inc.
Overview: Terrestrial Energy is developing Generation IV nuclear plants based on its Integral Molten Salt Reactor (IMSR) technology. It positions IMSR plants as zero-carbon, reliable, dispatchable sources of electricity and high-temperature industrial heat, extending nuclear’s use beyond power markets into industrial applications such as chemical processes and desalination, with commercialization efforts oriented toward the early 2030s.
Focus: Terrestrial Energy’s focus is on bringing IMSR plants from design into licensing, supply chain readiness, and first-plant delivery, with a value proposition centered on dispatchable clean power plus high-temperature heat for industrial customers. The company emphasizes cost reduction, versatility, and commercial deployment at scale.
Financial backers: N/A
10. Valar Atomics Inc.
Overview: Valar Atomics presents itself as a company scaling nuclear energy for heavy industrial power and clean hydrocarbon fuel production. The positioning is explicitly industrial, oriented around using nuclear as an enabling asset for large, energy-intensive sectors and for producing fuels with a lower emissions profile.
Focus: Valar’s focus is on nuclear-powered industrial energy systems, particularly applications that require high, steady power and that can be integrated into fuel production pathways. The emphasis is less on consumer grid supply and more on industrial output, including clean fuels.
Financial backers: Valar has been reported as backed by high-profile investors and strategics, including Palmer Luckey and Palantir CTO Shyam Sankar, alongside venture firms reported as round leads.
DOE’s 2025 selections are less a “best reactors” list and more a signal of what the U.S. is trying to unblock first: HALEU and fuel readiness, faster testing and authorization pathways, and deployable formats tied to real demand (defense and remote power, industrial heat and fuels, data center load growth). For investors, the most actionable opportunities are often adjacent to the reactor, including fuel fabrication and qualification, components and instrumentation and controls, licensing services, and standardized construction and commissioning.
For GPs and LPs, pressure-test each company on three questions: what bottleneck it removes (fuel, siting, licensing, manufacturing), what the first paying use case is with a credible contracting path, and how repeatable deployments scale after the first unit. Portfolio-wise, separate “platform exposure” (venture-style) from “project exposure” (infrastructure-style), and expect near-term winners to be the teams converting policy support into execution through customer pull, bankable deployment models, and scalable supply chains.
