NuScale secures US approval for enlarged design of its small nuclear reactor

The US Nuclear Regulatory Commission (NRC) has approved a revised version of the NuScale Power Module small modular reactor, with an output of 77 MWe. The agency had previously approved the original 50 MWe version of the SMR.

The NRC received NuScale’s first application to certify a reactor that could be expanded to up to 12 modules of 50 MWe in March 2017. The original design was subsequently certified in January 2023, becoming the first small modular reactor to receive regulatory approval for operation in the United States.

Following this certification, NuScale increased the module’s output to 77 MWe and submitted an application in January 2023 for approval of a configuration with six of these revised modules. The NRC accepted the application for review in July 2023.

Successful completion of the approval process

The NRC has now announced approval of this revised version of the SMR. “The standard design approval is based on the final safety evaluation report, which was issued on 28 May 2025,” the NRC said. The regulator also stressed that the technical review was completed ahead of schedule and under budget, demonstrating the NRC’s commitment to supporting the development of advanced reactor technologies safely and efficiently.

Design approval confirms that the reactor design meets the NRC’s applicable safety requirements. However, companies seeking to use this model must still apply for a permit to build and operate a specific reactor based on the approved design.

According to NuScale, the revised version retains the fundamental safety concepts and passive safety features that the NRC approved in the previous design. The changes mainly involve an increase in output and several specific design modifications in response to growing demand for higher installed capacity.

Significance for the energy market and partnership with ENTRA1 Energy

According to NuScale, approval of the revised design strengthens the position of its partner, ENTRA1 Energy, which holds the exclusive global commercial, distribution and deployment rights for NuScale reactor modules. With NRC approval, ENTRA1 Energy can expand its product offering for customers.

“We are excited that the NRC has approved our second application for a standard design review, this time for the 77 MWe version,” said NuScale President and CEO John Hopkins.

Increasing the installed capacity of a single module could be a way to reduce the cost per MWh generated. It has previously been reported that the estimated cost of building NuScale SMRs is too high.