Holtec’s SMR-300 Completes Key Regulatory Milestone

The GDA, conducted by the UK’s Office for Nuclear Regulation (ONR), the Environment Agency (EA), and Natural Resources Wales (NRW), concluded that there are no fundamental shortfalls against UK regulatory expectations with the SMR-300 design or its safety, security, and safeguards cases. This regulatory position provides strong independent validation of the SMR-300 reactor’s safety case and its design maturity instilling confidence in its readiness for deployment.

Building on this key regulatory milestone, Holtec is advancing development plans in partnership with EDF Energy for the Cottam site in Nottinghamshire, UK. Holtec and EDF Energy plan to leverage the UK’s Advanced Nuclear Framework to advance the Cottam project through site-specific licensing and into deployment, benefiting from streamlined regulatory pathways and government-enabled development.

This project momentum is reinforced by the growing alignment between UK and U.S. regulators, memorialized by their renewed Memorandum of Understanding to accelerate advanced nuclear deployment which was signed in September of last year. Holtec intends to leverage inter-country regulatory accord to support efficient licensing and faster project delivery in the United Kingdom following the Pioneer 1 & 2 SMR-300 project currently underway at Holtec’s Palisades site in Michigan.

After years of pre-engagement activities, Holtec is now an official license applicant with the USNRC after the submittal of the Pioneer 1 & 2 Construction Permit Application (CPA) at the end of 2025. On February 13th, 2026, the USNRC officially accepted Holtec’s application for review and published an expected review schedule that anticipates completion of the safety evaluations and environmental impact assessment by early to mid-2027.

Dr. Richard M. Springman, Holtec’s President of Global Clean Energy Opportunities, said:

“The positive GDA Step 2 regulatory statement is a key derisking milestone for our SMR-300 international deployment program, demonstrating our design and safety case approach meets international regulatory expectations in addition to U.S. NRC regulatory requirements – SMR-300 is a globally deployable design.”

Tim Parkes, Head of Safety Regulation for the Holtec SMR-300 GDA said:

“Our assessment covered 21 technical topic areas, and we have not identified any fundamental shortfalls. Throughout the GDA process, Holtec has demonstrated an open-minded and constructive approach that has been instrumental in enabling us to complete our assessment across all areas. Where aspects of the design, safety case, and methodologies require further development, these have been captured in 14 regulatory observations. Holtec has engaged positively with each of these observations, demonstrating a clear commitment to resolution. We are confident that their resolution plans, if implemented effectively, will address these observations and support a future design and safety case.”

Jane Bowie, EDF’s SMR Development Director, said:

“The opportunity to develop a new nuclear power project at the Cottam site is very exciting. This is a fantastic milestone for Holtec, and I congratulate them on the great work they have done with regulators. This enables us to move forward jointly with the site-specific reactor design assessment phase, which is a key enabler for our small modular reactor development”

Holtec is actively engaging with regulators in several countries that are seeking to build on the UK’s GDA process and collaborate with UK authorities to accelerate in-country licensing.