Southern California startup Valar Atomics announced that its 250‑megawatt small modular reactor, the Ward 250, achieved criticality on June 18. Reaching a self‑sustaining nuclear chain reaction marks the second such milestone in the Department of Energy’s pilot program this month, after Antares Nuclear. The breakthrough moves the U.S. closer to the initiative’s goal of three reactors online by early July.

The reactor pilot, unveiled in 2023, channels federal support to accelerate commercial nuclear deployment and diversify the power mix. Investors watch closely as small modular reactors promise lower capital costs and faster construction than traditional plants. Valar’s success validates its engineering approach and could attract downstream financing, positioning the firm for future contracts with utilities seeking clean baseload power, and could unlock government loan guarantees.

With two reactors now critical, the Energy Department is on track to meet its July 4 deadline, signaling government commitment to domestic nuclear innovation. The milestone may spur additional state‑level incentives and encourage other startups to enter the SMR race, and may influence upcoming regulatory reviews. Valar’s achievement therefore strengthens its bargaining power in a market eager for low‑carbon, dispatchable energy sources.