Small nuclear reactors (SMRs) are a possible source of energy, but they are not a panacea for the world’s energy crisis compared to their renewable energy and energy storage counterparts.
While I believe all energy technologies have some logical niches, small nuclear reactors have been overblown as a savior option, and large nuclear reactors are “dead in the water.” As a matter of courtesy, I am ignoring larger nuclear reactors since the last two Vogtle nuclear generation plants “experienced significant delays costing more than $20 billion beyond the originally estimated at $14 billion,” and were planned for completion in 2016 and 2017. However, they was completed seven years later, with costs exceeding $35 billion, making them the most expensive electricity source in the Americas.
Back to reality. The Federal Energy Regulatory Commission (FERC) released final 2024 data in February 2025, revealing that solar was eighty-one percent of new electric grid generation capacity, followed by wind at 8.3%, and then natural gas. Just an aside: approximately thirty percent of US solar capacity is in the form of small-scale (e.g., rooftop) systems that is not reflected in FERC’s data.
While solar and wind are not the baseload, they can be both individually paired together and with storage — such as pumped hydropower and battery storage (among others). And baseload renewables — geothermal (ten percent), biomass (eighteen percent), and water technologies (hydropower and marine energy) (twenty percent) — all cost less than SMRs and meet, conservatively, fifty percent of new US utility-interconnected electricity.
In fact, the US Department of Energy (DOE) states, “In fact, less than three percent of the more than 90,000 dams in the United States produce power, with thousands of non-powered dams offering excellent opportunities for investment.” And most experts agree that twenty-five percent of these 90,000 dams are technically sound to support hydropower turbines, which could produce electricity twenty-four hours a day at a third of the cost of SMRs.
Small modular reactor companies like Holtec and NuScale, which do not even have commercial prototypes, are years away from being mainstream in an electric market that is growing with urgent expansion needs that have to be addressed now.
SMRs still have the albatross of nuclear energy — safety, waste, water — to address. The Trump administration’s move to be able to override the Nuclear Regulatory Commission’s (NRC) review might sound good but will actually backfire. The industry has a history of close calls that new entrants with lesser supervision won’t bode well. The line in a Washington Post article noting “the country has not experienced a nuclear accident since the partial meltdown of the Three Mile Island reactor … in which there were no fatalities” is wanting, with a long list of shutdowns and accidents which could have had harsh consequences listed here.
Nuclear waste is still an issue with SMRs. Having more waste per megawatt hour (MWh) than larger reactors is not a good byproduct — as noted in Stanford University’s May 30, 2022, study, which found that, because of their smaller size, small modular reactors will experience more neutron leakage than conventional reactors. This increased leakage affects the amount and composition of their waste streams. The report added, “The more neutrons that are leaked, the greater the amount of radioactivity created by the activation process of neutrons,” and also found that “small modular reactors will generate at least nine times more neutron-activated steel than conventional power plants. These radioactive materials have to be carefully managed prior to disposal, which will be expensive.” The study found that the spent nuclear fuel from small modular reactors will be discharged in greater volumes per unit energy extracted and can be far more complex than the spent fuel discharged from existing power plants.
The Trump administration’s approach to only allow SMRs on federal lands makes some sense, but only if the waste ends up being entombed near the reactors rather than trucking them around the United States, which is open to human error and transport accidents. On January 24, 2024, a drunk driver crashed into a truck in southern New Mexico that was hauling twenty-eight 55-gallon drums of nuclear waste to the Waste Isolation Pilot Project. Waste storage adds to the cost.
The extraction, conversion, and use of energy is the single largest use of fresh water in the United States, with only agriculture as a rival. Yes, some SMRs do use water, the USDOE states, “particularly light water, as a coolant and neutron moderator. However, some SMR designs are exploring alternative coolants like liquid metal, gas, or molten salt. The specific coolant choice depends on factors like reactor type, design, and intended application.”
Since temperatures are becoming warmer in the United States, some nuclear plants in recent years have had to be shut down until water temperatures in nearby rivers and lakes fell to levels low enough to adequately cool the reactors. The good news is that the SMR industries are aware of this and exploring options.
All energy technologies have pros and cons, but SMRs are the newest technologies on the block, with both transmission lines and distribution lines at full capacity and aging. So, they have a steep climb. The entire portfolio of renewable energy and energy storage has far more flexibility to be on-site, at local substations, and along transmission and distribution lines — with minimal safety and waste issues. SMRs are possible, yes, but they are not as fast and flexible as their renewable energy and energy storage counterparts.
About the Author: Scott Sklar
Scott Sklar is an adjunct professor and the Sustainable Energy Director at the Environment and Energy Management Institute at The George Washington University. He is also the founder and president of the Stella Group, a twenty-five-year-old global strategic technology optimization owners-rep firm for clean distributed energy users and companies. Prior to coming to GWU, Professor Sklar ran both the national solar & biomass-electric trade groups for fifteen years, and had worked as an energy aid for Senator Jacob K. Javits (D-NY) and co-founded the Congressional Solar Caucus.
Image: Shutterstock/fewerton
