ARC Clean Technology signs partnership with Idaho National Laboratory to advance ARC-100 sodium-cooled fast reactor deployment

ARC Clean Technology has signed a Strategic Partnership Project agreement with Battelle Energy Alliance, the contractor that manages Idaho National Laboratory, setting up a multiyear framework to design, demonstrate, and deploy the ARC-100—a 100-megawatt sodium-cooled fast reactor. For a nuclear start-up founded in 2006 that’s still working toward its first reactor deployment, this is a meaningful step forward.

ARC and INL formalize multiyear reactor collaboration

The Strategic Partnership Project agreement pairs ARC with Battelle Energy Alliance, which manages and operates INL on behalf of the Department of Energy. Under the deal, INL will support a wide range of technical functions across the ARC-100’s development lifecycle—engineering and design, advanced materials, high-performance computing, irradiation testing, reactor commissioning, and site development.

The scope is intentionally broad. ARC described the collaboration as covering “the full lifecycle from detailed design through first-of-a-kind deployment,” which means INL’s role doesn’t stop at early-stage research. It extends all the way through the reactor’s first commercial operation.

It’s now planning to pursue a license under 10 CFR Part 53, the regulatory framework the NRC recently built specifically for advanced reactor designs.

One thing the agreement doesn’t do is fast-track ARC into INL’s more exclusive programs. Unlike some recent high-profile reactor projects at the lab, ARC hasn’t been named a participant in either INL’s Reactor Pilot Program or its Nuclear Energy Launch Pad. The ARC-100 will go through standard Nuclear Regulatory Commission licensing under 10 CFR Part 53—the newly established framework for advanced reactors—rather than any expedited DOE authorization pathway.

Why ARC chose INL and what the SPP agreement provides

The DOE’s Strategic Partnership Projects Program exists to connect private companies with the specialized resources that national laboratories offer. For ARC, that means access to INL’s distinctive facilities, technical personnel, and accumulated expertise—things that would be difficult or impossible to replicate elsewhere.

The fit goes beyond convenience. The ARC-100 draws directly on lessons from INL’s Experimental Breeder Reactor-II, a sodium-cooled fast reactor that operated on the same Idaho site for more than 30 years. That history created deep institutional knowledge around sodium-cooled reactor behavior, safety characteristics, and fuel performance—exactly what ARC needs as it pushes its design forward. INL’s familiarity with sodium-cooled systems makes it a natural home for the next chapter of that technology.

The ARC-100 uses metallic uranium-zirconium alloy fuel paired with a supercritical CO₂ Brayton cycle power converter. Technically distinct from EBR-II, it nonetheless shares a common lineage with it.

Deployment timeline and licensing pathway

ARC’s path toward deployment got a real boost in 2020, when the DOE selected the company for its Advanced Reactor Demonstration Program‘s ARC-20 pathway—short for Advanced Reactor Concepts 2020, a name that happens to overlap with the company’s own branding by coincidence. That selection came with $27.5 million in federal funding and a stated goal of deploying the ARC-100 by the mid-2030s.

That same year, ARC began prelicensing engagement with the NRC. It’s now planning to pursue a license under 10 CFR Part 53, the regulatory framework the NRC recently built specifically for advanced reactor designs. Part 53 offers a more flexible licensing pathway than existing rules, which were written with light-water reactors in mind.

The latest announcement doesn’t include a specific target date for NRC approval or the start of commercial operation. ARC’s press release framed the INL partnership around technical collaboration and lifecycle support, without attaching firm milestones to the licensing process. The mid-2030s deployment goal from the 2020 ARDP selection remains the most concrete public timeline on record.

ARC’s two-decade history and existing development work

By most measures, ARC Clean Technology is one of the longest-running advanced reactor start-ups in the United States. Founded in 2006, it predates better-known names like TerraPower, X-energy, and Oklo by several years—though that longevity also reflects just how long the road from concept to deployment tends to be in the nuclear industry.

The company’s early years aren’t extensively documented, partly because it operated under several different names over time: Advanced Reactor Technologies, Advanced Reactor Concepts, and ARC Nuclear. Early patent filings show the team was actively developing its reactor concept in the years after founding, and DOE publications from around 2015 reference ARC’s plans for a sodium fast reactor, according to the American Nuclear Society.

In 2017, ARC struck a partnership with GE Hitachi Nuclear Energy to jointly develop, license, and deploy the ARC-100 in Canada—an agreement that gave ARC access to intellectual property related to GEH’s Prism reactor design. Canadian development has continued steadily since. The ARC-100 has advanced through multiple stages of regulatory review with the Canadian Nuclear Safety Commission, and ARC has established deployment plans in Alberta.

Specialized facilities that private companies can’t easily access

The INL partnership gives ARC a technically credible, well-resourced collaborator for what’s still the hardest part of its journey: moving from a well-developed design to an operating reactor. INL brings sodium-cooled reactor expertise rooted in decades of EBR-II operation, along with specialized facilities that private companies can’t easily access on their own.

ARC will pursue NRC licensing under 10 CFR Part 53, without access to INL’s expedited DOE authorization programs. The company holds $27.5 million in ARDP funding and is targeting mid-2030s deployment. No specific NRC approval date has been announced. Progress on the Canadian front continues in parallel, keeping ARC’s options open on both sides of the border.

Kelly Lippke

Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.