By Kennedy Maize
The U.S. Nuclear Regulatory Commission last week approved NuScale Power’s evolutionary small modular reactor design, a 77-MW light water cooled and moderated pressurized water reactor in a six-reactor package.
The “US460” SMR is a scaled-up design based on the NRC’s 2020 approval of NuScale’s original 50-MW machine. The NRC staff, in the final act of its approval process, issued the reactor’s “Final Safety Analysis Report” last Thursday (May 28). NuScale can now offer potential customers the only SMRs with NRC design approval, a necessary step toward getting a reactor on the ground and generating power.
In a news release, the NRC noted, “The US460 design continues to use natural ‘passive’ processes such as convection and gravity in its operating systems and safety features. The US460’s six modules, producing a total of approximately 460 megawatts of electricity, are all partially immersed in a safety-related pool built below ground level.”
The NRC staff completed the analysis some two months ahead of the time the reactor company had predicted in its planning for the SMR.
While the basic design of the NuScale reactor is familiar, the venerable PWR, the design did have new elements. Nuclear physicist Edwin Lyman, the nuclear safety analyst for the Union of Concerned Scientists, told The Quad Report in an email that the design “has enough novel features that it kept the NRC staff quite busy. One quite striking thing is how incredibly complex the design actually is.
“Passive safety systems do not go hand in hand with simplicity. There were a number of ‘high-impact technical issues’ that the staff managed to make go away, at least for the moment.
“Some [Advisory Committee on Reactor Safety] members didn’t seem satisfied until the very last moment, but a lot of hand-waving was involved. And a large number of technical staff dissented from the SER that accepted NuScale’s argument that the DC power system does not have to be safety-related. In fact, safety-related batteries suitable for NuScale’s use do not even exist, so the applicant didn’t have a choice other than to build its own factory to make them.”
NuScale (NYSE:SMR) in a written statement said that the “uprated SMR design will support a wider range of off-takers and consumers seeking clean energy through small modular reactor technology.”
The Oregon-based company, founded by technologists affiliated with Oregon State University, said the NRC action will strengthen its marketing partner, Entra1 Energy, “to produce and deliver energy as the most near-term American SMR power solution via ENTRA1 Energy Plants™ with NuScale SMR technology inside.” ENTRA describes its role as “NuScale’s exclusive global strategic partner commercializing the NuScale SMR Technology. Through this partnership, ENTRA1 develops, finances, owns and operates energy production plants powered by the NuScale SMR Technology.”
NuScale’s stock has been soaring in the past month, before the NRC’s thumbs up on the reactor design. Zachs Investment Research reported before the NRC action that “SMR shares have surged 92.8% over the past month, significantly outperforming the Zacks Computer and Technology sector’s growth of 8.5% and the Zacks Electronics – Power Generation industry’s return of 91.6%.”
Zach’s said, “SMR’s strong stock price performance is attributed to a robust top-line performance in the first quarter of 2025, with total revenues rising year over year to $13.4 million from $1.4 million, driven by the Front-End Engineering and Design (FEED) Phase 2 project and the Technology License Agreement for Romania’s RoPower Doicesti power plant.”
SMR prices were falling a bit as the NRC announcement came out – down 78 cents from $32.20 on May 30. A year before, SMR’s stock price was $6.61/share.
The NuScale reactor design likely was the most familiar the NRC will be asked to approve in the future. The agency will also have to examine fast reactors, molten salt moderated and cooled designs, sodium coolant, and other unconventional approaches to nuclear power.
On top of that, most of the more advanced designs are planned around HALEU (elevated uranium enrichment) fuels.
Will these pose extra challenges to the agency’s reviews. Looking at HALEU fuel, UCS’s Lyman said, “Other than issues related to the different reactor designs and burnups, it affects the criticality analysis of fresh and spent fuel storage and transportation, and there are large gaps in the necessary data.
“And then there is the security issue, which is still not being addressed.”
–Kennedy Maize