Will SMRs actually be cheaper than traditional nuclear plants?
The short answer is: probably not, at least not anytime soon. The core economic problem is that SMRs sacrifice economies of scale—the principle that larger plants produce cheaper electricity per unit because fixed costs are spread over more output. A 2021 analysis in IEEE Access explains that because SMRs have lower generation capacity, their construction and operational costs per unit of electricity will be higher than those of large nuclear plants, which themselves are already uncompetitive in today's electricity markets [4]. A 2023 study from Germany reinforces this, noting that the only currently viable nuclear investment option is Generation III reactors with capacities above 1,000 MW, while SMRs are surrounded by 'high uncertainty' economically [6].
Proponents argue that modular construction and 'learning by doing' will drive costs down over time. But the historical record does not support this optimism. The same IEEE Access analysis examined past cost trends and concluded that savings from learning and modular construction will be 'inadequate to compensate for the economic challenges resulting from the lower generation capacity' [4]. A 2023 review of SMR deployment obstacles similarly identifies 'economy of scale and financing' as among the most hindering constraints, noting that the commercial viability of SMRs depends on rapid up-scaling—something that has not yet occurred [5].
There is some nuance, however. A 2023 study on SMRs for Indonesia found that certain designs—like the HTR-PM, CAREM 100 MW, and VBER 300 MW—could achieve levelized costs of electricity (LCOE) between $0.06 and $0.12 per kWh at discount rates of 5–10%, which is competitive with local coal and hydropower in Indonesia [1]. But even that study acknowledges that these are 'economy scale' versions of smaller prototypes, and the smaller prototypes themselves (like CAREM-25 and KLT-40S) had LCOE estimates above $0.07 per kWh and were still in demonstration stages [1]. So while some scaled-up SMR designs might eventually compete in niche markets, the overall evidence points to higher costs, not lower.
Do SMRs create less nuclear waste than traditional reactors?
No—and this is a critical finding that overturns a common assumption. A highly cited 2022 study in the Proceedings of the National Academy of Sciences analyzed waste streams from three SMR designs and found that SMRs will produce 'more voluminous and chemically/physically reactive waste' than conventional large light-water reactors (LWRs) [3]. The reason is fundamental to the physics: SMRs have higher neutron leakage due to their smaller core size, which means they generate more problematic radionuclides per unit of electricity. The study concludes that 'most designs are inferior to LWRs with respect to the generation, management, and final disposal of key radionuclides in nuclear waste' [3]. This directly challenges the narrative that SMRs are a cleaner or simpler waste solution.
This waste issue also ties back to economics. A 2023 paper on nuclear economics notes that decommissioning and waste storage costs must be considered from the very outset of reactor planning, and that there are 'interdependencies between technology choices and storage issues, for example volume composition' [6]. If SMRs produce more waste per kilowatt-hour, that adds to their long-term cost burden, further undermining their economic case.
Can SMRs be built faster and with less risk than large reactors?
The promise of faster construction is one of the main selling points of SMRs, but the evidence suggests that significant regulatory and licensing hurdles remain. A 2023 review of SMR deployment obstacles identifies 'technology choice, licensing, economy of scale and financing, public acceptance, supply chain, and proliferation' as major barriers [5]. The paper emphasizes that these are not minor issues—they are 'hindering constraints' that require much deeper analysis than the SMR community has conducted so far [5].
A 2024 review in the Korean Journal of Chemical Engineering acknowledges that SMRs could offer 'more flexible, scalable, and economically viable options' in principle, but it also highlights that over 70 types of SMRs are under development globally, each with different designs, safety features, and regulatory pathways [2]. This diversity, while innovative, complicates licensing and standardization—the very things needed to achieve the promised schedule savings. The paper identifies 'key technologies and strategic considerations' still needed for successful deployment [2], implying that the path to faster construction is far from certain.
In summary, while SMRs may eventually offer some schedule advantages in niche applications (e.g., replacing retired coal plants or serving small grids), the evidence as a whole indicates that they do not currently solve the cost and schedule problems of traditional nuclear power. They face their own set of economic, waste, and regulatory challenges that are at least as daunting as those of large reactors.
About These Sources
This answer is built on 6 peer-reviewed studies — published from 2021 to 2024, 1 from 2024 or later, 1 in Q1 journals, collectively cited 254 times — selected as the most relevant from 6 studies that passed quality screening, drawn from 51 papers retrieved from a database of over 500 million.
Sources used in this answer
Nuclear Power Plant to Support Indonesia’s Net Zero Emissions: A Case Study of Small Modular Reactor Technology Selection Using Technology Readiness Level and Levelized Cost of Electricity Comparing Method
In a technology readiness and cost comparison study for Indonesia, SMRs with TRL 7-8 had LCOE estimates of $0.06–$0.12/kWh at 5–10% discount rates, competitive with local coal and hydropower, but smaller prototypes had higher costs and were still in demonstration stages.
Review of Small Modular Reactors: Challenges in Safety and Economy to Success
A review of over 70 SMR designs under development found that reducing reactor size impacts efficiency, safety, and cost, and identified key technologies and strategic considerations still needed for successful deployment.
Nuclear waste from small modular reactors
A waste stream analysis of three SMR designs found they produce more voluminous and chemically/physically reactive waste per unit of electricity than conventional large light-water reactors, due to higher neutron leakage.
Small Modular and Advanced Nuclear Reactors: A Reality Check
An analysis of economic challenges concluded that SMRs will have higher construction and operational costs per unit of electricity than large nuclear plants, and that historical learning and modular savings are inadequate to compensate.
Small Modular Reactor Deployment and Obstacles to Be Overcome
A review of SMR deployment obstacles identified technology choice, licensing, economy of scale, financing, public acceptance, supply chain, and proliferation as major hindering constraints requiring deeper analysis.
Economics of new nuclear power plants – assessment of investments into Generation III, small modular reactors and non-light-water reactors
An economic assessment of new nuclear plants found that Generation III reactors (>1,000 MW) are the only currently viable investment, while SMRs and non-light-water reactors face high uncertainty and interdependencies between technology choice and waste storage costs.