Utah San Rafael Energy Lab (USREL) provides the specialized testing site and infrastructure to host Valar Atomics’ Ward 250 test reactor. Developed, built, and operated by the Valar team under the U.S. Department of Energy’s (DOE) Reactor Pilot Program, this Generation IV high-temperature gas reactor (HTGR) utilizes the USREL facility in Emery County to validate advanced reactor physics and proceed with power ascension testing.
On June 18, 2026, the Ward 250 successfully achieved full-power fueled criticality at the lab, fulfilling a historic milestone under Executive Order 14301 ahead of the July 4 deadline. This achievement marks the first time a DOE-authorized advanced reactor has been built and operated outside of the national laboratory system, making USREL the premier independent site for commercial advanced nuclear deployment.
Reactor Capabilities and Testing Focus
- Advanced TRISO Fuel Validation: Valar’s Ward 250 microreactor utilizes robust tri-structural isotropic (TRISO) fuel particles. The testing at the USREL site verifies the exceptional thermal resistance and intrinsic safety profile of Valar’s design, which is engineered to contain radioactive fission products effectively and remain impossible to melt under extreme conditions.
- Integrated System Performance: The compact reactor reached criticality as a complete, fully integrated system configured for power operations. It is ultimately designed to scale up to a 5 MW design capable of generating clean electricity for commercial and industrial use.
- Industrial & AI Energy Applications: The operational data gathered at the lab lays the groundwork for mass-scaling these helium-cooled, graphite-moderated reactors into “gigasites.” These clusters are designed by Valar to meet the massive power demands of modern AI data centers, industrial heat applications, and carbon-neutral fuel synthesis.
USREL provides the essential location and regulatory-quality environment needed for pioneering companies to transition advanced reactor technologies directly from localized testing to the commercial grid.
