What Happened to Small Modular Reactors (SMRs)?

Small Modular Reactors (SMRs) emerged as a promising solution to the challenges of traditional large-scale nuclear power, offering advantages such as modular construction, smaller footprints, enhanced safety features, and greater siting flexibility. These reactors, generally producing up to 300 megawatts electric (MWe) per unit, are designed to be factory-fabricated and transported to sites for assembly, aiming to reduce capital costs and construction timelines. The initial push for SMRs was driven by global decarbonization goals, the need for reliable baseload power, and the desire to replace aging fossil fuel infrastructure.

Key turning points in SMR development include the U.S. Nuclear Regulatory Commission (NRC) issuing its Final Safety Evaluation Report for NuScale Power's SMR design in August 2020, followed by the certification of the design in July 2022, which took effect in February 2023, marking it as the first SMR approved for use in the United States. This regulatory milestone was seen as a significant step towards commercial deployment. However, a major setback occurred in November 2023 when NuScale and Utah Associated Municipal Power Systems (UAMPS) mutually agreed to terminate the Carbon Free Power Project (CFPP) in Idaho. The cancellation was primarily attributed to lower-than-expected subscriptions from UAMPS customers, highlighting the commercial viability challenges and the difficulty of being a 'first-mover' in a nascent technology market.

Despite this setback in the U.S., the global landscape for SMRs has continued to evolve rapidly. China has taken a leading role, with its High-Temperature Gas-cooled Reactor Pebble-bed Module (HTR-PM) operating since December 2023 and its Linglong One (ACP100) SMR beginning commercial operation in the first half of 2026, making it the world's first commercial land-based SMR. Russia also has operational floating SMRs. In the United Kingdom, Rolls-Royce SMR was selected as the preferred technology partner in June 2025 and secured regulatory justification in March 2026. A landmark contract was signed in April 2026 with Great British Energy - Nuclear to begin work on deploying three Rolls-Royce SMRs at Wylfa, North Wales, with plans for further deployment in Sweden and the Czech Republic.

As of August 2026, the current status of SMRs is characterized by a dual narrative of continued challenges and accelerating momentum. The demand for reliable, carbon-free power, particularly from the booming AI and data center industries, has reinvigorated interest and investment. The U.S. Department of Energy (DOE) has continued to provide substantial funding, including $800 million in December 2025 for two SMR projects (TVA and Holtec) and over $94 million in May 2026 to eight companies to expedite deployment by addressing licensing, supply chain, and site preparation gaps. Japan has also announced plans to invest over $65 billion in U.S. SMR projects, including those by GE Vernova/Hitachi and NuScale, and Mitsubishi Heavy Industries has begun developing SMRs for Japan's own energy future. While NuScale's stock has faced significant pressure in 2026 due to commercialization uncertainties, the company is pursuing new partnerships, including with Standard Power for data centers. The European Union adopted an SMR strategy in March 2026 to accelerate development and deployment. The industry is focused on moving from design and regulatory approval to tangible construction and commercial operation, with supply chain development and financing remaining critical hurdles.