Valar Atomics
🇺🇸 US · Founded 2023 · Active
Valar Atomics is a US reactor developer founded in 2023. It is designing a high-temperature gas-cooled reactor using TRISO particle fuel and plans to build many identical units on large sites it calls gigasites, selling hydrogen, industrial heat, data-centre power and synthetic hydrocarbon fuels rather than grid electricity. It has built Ward Zero, a full-size non-nuclear test rig heated by electric elements, and is working with the Department of Energy, the San Rafael Energy Research Center and the State of Utah to bring a test reactor, Ward 250, into operation in Utah. It set a goal of doing so before 4 July 2026; its website, checked in September 2026, still states that goal and does not report the outcome.
- Sector
- Fission
- Technology
- High-temperature gas-cooled reactor
- Fuel
- High-assay low-enriched uranium
- Role
- Reactor developer
Terms
- High-temperature gas-cooled reactor
- Helium-cooled and graphite-moderated, running far hotter than a water reactor. Fuel is TRISO particles, typically formed into pebbles or prismatic blocks, at LEU or HALEU enrichment depending on the design. The high outlet temperature suits industrial process heat as well as electricity.
- High-assay low-enriched uranium
- High-assay low-enriched uranium: uranium enriched to between 5% and just under 20% uranium-235, as the US Department of Energy defines it. It is still formally low-enriched, because the international line for highly enriched uranium is 20%, which is why many designs specify 19.75%. The binding supply constraint for many advanced reactor designs. The 5 to 10% part, which carries lighter US physical-security requirements than material from 10% up, is also tagged as LEU+. A developer calling fuel in that band 'LEU' is making a labelling choice, not describing a different enrichment.