Europe’s growing appetite for small modular reactor technology is drawing fresh attention to two U.S. nuclear developers still working to establish their first commercial operations.
NuScale Power (NYSE: SMR) and Oklo (NYSE: OKLO) are both advancing SMR technology, yet neither company has completed a commercially operational reactor at scale, leaving investors watching closely for progress.
Both stocks have struggled significantly in 2026, with Oklo shares down 45% and NuScale shares off 36%, reflecting investor impatience with timelines that stretch deep into the next decade.
NuScale’s current revenue stream is tied to consulting services it provides to Fluor, a construction company collaborating with RoPower, a Romanian power company, on a proposed nuclear facility.
In that arrangement, NuScale is acting as an advisor, helping RoPower demonstrate that its planned plant is a viable and fundable project worth pursuing.
RoPower’s broader ambition is to link six of NuScale’s SMRs together to create a single, large-scale nuclear power plant, which would represent one of the most significant deployments of SMR technology anywhere in the world.
NuScale does hold approved plans for its SMR design, but has not yet built or sold a unit for actual commercial electricity generation, making the Romania project a pivotal test case for the company.
Oklo’s business model is notably more vertically integrated, with the company planning to handle fuel fabrication, electricity and heat sales, and eventual fuel recycling under one roof.
The company has secured a deal with Meta Platforms under which the tech giant can prepay for power and provide funding toward Oklo’s reactor project in Ohio, with full power output targeted by 2034.
In a significant technical milestone announced on August 6, Oklo reported that its small modular reactor in Texas had achieved criticality, meaning the reactor is capable of sustaining a steady and controlled energy output.
According to Bloomberg reporting, Oklo’s Texas reactor is the fifth nuclear reactor of its kind globally to reach that level of operational capability, marking a genuine step forward for the company.
The criticality milestone matters because it moves Oklo from a purely developmental company toward one that can demonstrate its core technology actually functions as designed under real-world conditions.
For NuScale, Europe remains the most concrete near-term opportunity, with the Romania project offering a potential proof-of-concept that could attract further contracts across a continent actively seeking to reduce energy dependence.
European governments have accelerated nuclear energy commitments following years of energy market volatility, creating a policy environment that favors long-term investment in new reactor designs including SMRs.
Both companies remain pre-commercial in meaningful ways, and investors will be weighing each new operational milestone against the substantial capital and time still required before revenues reflect their full ambitions.
