Valar Atomics Achieves First Criticality in DOE Pilot Program, Validating Core Design

Nevada National Security Site – Valar Atomics announced on November 17, 2025, that its NOVA Core successfully achieved zero-power criticality at Los Alamos National Laboratory’s (LANL) National Criticality Experiments Research Center (NCERC) at the Nevada National Security Site (NNSS). This milestone marks Valar Atomics as the first company in the U.S. to reach criticality under the U.S. Department of Energy’s Reactor Pilot Program. The achievement validates the core design and physics ahead of planned power operations.

Zero-power criticality, often referred to as "cold criticality," signifies a self-sustaining chain reaction of uranium-235 within a nuclear core without reaching full operating temperatures or actively removing heat. This foundational step allows Valar Atomics to thoroughly understand the neutronic characteristics of its core and verify assumptions about fuel, moderators, and control mechanisms. Valar Atomics Founder and CEO, Isaiah Taylor, stated, > “Zero-power criticality is a reactor’s first heartbeat, proof the physics holds.”

The DOE Pilot Program, established under Executive Order 14301, aims to have at least three test reactors achieve criticality by July 4, 2026. Valar Atomics' success aligns with this national objective, providing a vital prototyping and demonstration platform for advanced reactor designs. The program allows companies to test designs in a research capacity, bypassing some lengthy regulatory processes.

Project NOVA, a collaboration between LANL NCERC and Valar Atomics, involves a series of criticality experiments on a High Assay Low Enriched Uranium (HALEU) TRISO-fueled core. Valar Atomics is developing a high-temperature gas-cooled, graphite-moderated reactor, with the NOVA core modeling a subsection of their Ward250 core. The Ward250 project is slated to begin power operations next year in Utah.

Valar Atomics recently secured a $130 million funding round, with investors noting the company's aggressive goals and innovative approach to nuclear energy. The company aims to build "nuclear gigasites" to supply energy for heavy industry, hydrogen production, and the growing demands of AI infrastructure. This achievement is a significant step towards their vision of commercial-scale, factory-built nuclear reactors.