Small Isn't Always Beautiful

The report challenges the claims that small modular reactors (SMRs) are inherently safer and more cost-effective than large-scale nuclear plants. It argues that SMRs suffer from negative economies of scale and that vendors are pressuring the Nuclear Regulatory Commission (NRC) to weaken safety, security, and emergency planning standards to make the technology financially viable. The author warns that reducing security staffing or shrinking emergency planning zones could increase public risk, especially in the wake of the Fukushima Daiichi accident.

• SMRs are likely to be less cost-effective than large reactors due to the loss of economies of scale, meaning the capital cost per kilowatt is higher for smaller plants.
• The economic viability of SMRs depends heavily on government subsidies and the ability to access international export markets, particularly China, as domestic demand may be insufficient.
• To reduce costs, SMR vendors are pressuring the Nuclear Regulatory Commission (NRC) to weaken regulations regarding security staffing, control room staffing, and emergency planning.
• Proposed reductions in security staffing—some as high as 70 to 80 percent—could leave SMRs vulnerable to terrorist attacks, as the number of armed responders might fall below the number of potential attackers.
• The push to reduce the 10-mile inhalation emergency planning zone (EPZ) for SMRs is contradicted by evidence from the Fukushima Daiichi accident, where radiation levels warranted evacuation well beyond 10 miles.
• SMR designs often utilize smaller and less robust containment structures to save costs, which increases the risk of overpressurization and hydrogen explosions during severe accidents.
• Deploying multiple SMRs at a single site introduces new risks, as common-mode failures or accidents affecting multiple units could overwhelm emergency personnel and equipment.
• While underground siting is promoted as a safety benefit, it increases construction costs and may complicate emergency access or increase vulnerability to flooding.

APA

Lyman, E. (2013). Small Isn't Always Beautiful. Union of Concerned Scientists. https://www.ucs.org/sites/default/files/2019-10/small-isnt-always-beautiful.pdf

Chicago

Lyman, Edwin. Small Isn't Always Beautiful. Union of Concerned Scientists, 2013. https://www.ucs.org/sites/default/files/2019-10/small-isnt-always-beautiful.pdf.

Wikipedia

{{cite report |last1=Lyman |first1=Edwin |title=Small Isn't Always Beautiful |publisher=Union of Concerned Scientists |date=September 2013 |url=https://www.ucs.org/sites/default/files/2019-10/small-isnt-always-beautiful.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{lyman2013small, author = {Lyman, Edwin}, title = {{Small Isn't Always Beautiful}}, institution = {Union of Concerned Scientists}, year = {2013}, month = sep, url = {https://www.ucs.org/sites/default/files/2019-10/small-isnt-always-beautiful.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }