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Nuclear Energy

Written by Dr. Tomy Granzier-Nakajima, Dr. Jenny Bratburd
Published on February 23, 2023
Research Highlights

Nuclear energy is a low emission energy source that may reduce future electricity.

Deaths from production accidents and exposure to harmful materials are substantially lower in nuclear, solar and wind energy compared to coal or natural gas.

Nuclear power plant closures are high and new construction is low.

For an overview of state and federal nuclear restrictions and incentives, see our Policy Memo.

Nuclear energy is a low carbon emission source that may reduce future electricity costs.

Nuclear energy generates 20% of the electricity in the U.S. (DOE n.d.).

  • Missouri’s only nuclear power plant, located in Callaway County, generates about 10% of the state’s electricity (EIA 2022).

Fuel Source and Emissions. Nuclear power produces almost no greenhouse gas emissions during operation (Jawerth 2020). It is reliable at a large scale and can be produced almost anywhere on Earth.

U.S. nuclear power relies on uranium, which is a non-renewable fuel source (NRC 2020).

  • The Organization for Economic Cooperation and Development predicts there is enough global uranium to produce nuclear fuel for over 250 years (NEA 2020).

Electricity Generation. Electricity sources can be classified based on energy production costs, how often they are called on to meet demand, and whether they can be reliably called on to meet demand.

  • “Baseload” power sources, such as nuclear energy, are those that can meet the minimum electricity demands on a grid, while sources that respond to changing electricity demand can be classified as “load-following” or “peaking” resources (e.g., combustion turbines fueled by natural gas; EIA 2012).
  • “Firm” energy sources (e.g., nuclear, hydro-electric, coal, natural gas) can reliably produce electricity to meet demand during any season for long durations (Sepulveda 2018).

In a comprehensive study of how energy source and decarbonization goals will impact future electricity costs, low-carbon, firm energy sources (e.g., nuclear energy) consistently lowered the price of electricity (Sepulveda 2018). In fully decarbonized scenarios, electricity costs decreased by 10-62%.

  • The study investigated nearly 1,000 hypothetical scenarios that varied future costs for renewable and other energy technologies, carbon dioxide emissions targets, the impact of flexible electricity demand scheduling, and long-distance transmission capacities.

Nuclear energy mortality is low compared to other sources.

Production Accidents. Energy production can cause injury and/or death to those who are exposed to radiation, workplace accidents, or increases due to air pollution.

  • The overall mortality rate per terawatt-hour (TWh) of nuclear energy produced (0.07) is lower than coal (24.622) and natural gas (2.82), and similar to solar (0.02) and wind (0.04; Markandya 2007; Sovacool 2016).

Catastrophic nuclear reactor accidents (e.g., Fukushima, Chernobyl) have long-term ecological effects.

  • Radioactive strontium and cesium are products of the nuclear reaction and will continue to remain in the vicinity of the Chernobyl nuclear power plant for decades (WHO 2005).
  • Plutonium and americium, another nuclear byproduct, will persist for thousands of years, though they are primarily harmful if inhaled or ingested and their human exposure is low.
  • There is evidence that several species in the area have unusually high levels of harmful mutations that may decrease reproduction and wildlife survival (Mousseau 2021).

Spent Nuclear Fuel. Spent nuclear fuel is highly radioactive and can be dangerous to humans for thousands of years (EIA 2021).

All U.S. nuclear reactors store spent fuel in concrete reinforced pools that cool the fuel and shield from radiation (NRC 2019; Rusco 2021). After 5-10 years, the fuel is moved to a dry cask to further cool and shield from radiation.

  • As of 2019, most spent nuclear fuel (approximately 86,000 metric tons) is stored on-site at reactor facilities (Rusco 2021; NRC n.d.).
  • There is no long-term plan for U.S. spent nuclear fuel storage (EPA n.d.; Suman 2018).

Nuclear reactor closures are high and new construction is low.

The U.S. currently has 93 nuclear reactors. Twelve have shut down since 2013, with the most recent shutdown citing low electricity costs and increased operation costs (Holt 2021). The Watts Bar Unit 2 reactor in TN began operation in 2016 and was the first new reactor in the U.S. in nearly two decades (Scott 2018). Two new reactors in GA are expected to be completed in 2023 (SC n.d.).

  • Weak growth in electricity demand and electricity production from natural gas and renewables drives nuclear plant closures and barriers to new construction (Scott 2018; Holt 2021; Shea 2017).

Construction costs for many nuclear reactors often become more expensive than initially estimated, with an average increase in cost of 117%, compared to hydroelectric (71%), wind (8%) and solar (1%; Gilbert 2017).

  • Nuclear reactor sites require precise design and construction and often require site-specific reworks that were not anticipated during the original quote. This can increase labor costs due to longer-than-expected construction time. (Eash-Gates 2020).

One alternative to large nuclear reactors is the development of small, modular reactors which may require less upfront costs; however, this technology is still developing (Cho 2019).

  • The U.S. Nuclear Regulatory Commission certified the first small modular reactor design in January (DOE 2023).

For an overview of state and federal nuclear restrictions and incentives, see our Policy Memo.


Cho, A. (2019, February 21). Smaller, safer, cheaper: One company aims to reinvent the nuclear reactor and save A warming planet. Science. Retrieved February 20, 2023, from https://www.science.org/content/article/smaller-safer-cheaper-one-company-aims-reinvent-nuclear-reactor-and-save-warming-planet  

Eash-Gates, P., Klemun, M. M., Kavlak, G., McNerney, J., Buongiorno, J., & Trancik, J. E. (2020). Sources of cost overrun in nuclear power plant construction call for a new approach to engineering design. Joule, 4(11), 2348–2373. https://doi.org/10.1016/j.joule.2020.10.001  

Environmental Protection Agency (EPA). (n.d.). Nuclear Power Plants. United States Environmental Protection Agency. Retrieved January 18, 2022, from https://www.epa.gov/radtown/nuclear-power-plants  

Gilbert, A., Sovacool, B. K., Johnstone, P., & Stirling, A. (2017). Cost overruns and financial risk in the construction of Nuclear Power Reactors: A critical appraisal. Energy Policy, 102, 644–649. https://doi.org/10.1016/j.enpol.2016.04.001  

Holt, M., & Brown, P. (2021). (rep.). U.S. Nuclear Plant Shutdowns, State Interventions, and Policy Concerns. Congressional Research Service (CRS). Retrieved February 20, 2023, from https://crsreports.congress.gov/product/pdf/R/R46820/4 

Jawerth, N. (2020, September). What is the clean energy transition and how does nuclear power fit in? IAEA. Retrieved February 21, 2023, from https://www.iaea.org/bulletin/what-is-the-clean-energy-transition-and-how-does-nuclear-power-fit-in  

Markandya, A., & Wilkinson, P. (2007). Electricity Generation and Health. The Lancet, 370(9591), 979–990. https://doi.org/10.1016/s0140-6736(07)61253-7  

Mousseau, T. A. (2021). The Biology of Chernobyl. Annual Review of Ecology, Evolution, and Systematics, 52(1), 87–109. https://doi.org/10.1146/annurev-ecolsys-110218-024827  

National Conference of State Legislatures (NCSL). (n.d.). States restrictions on New Nuclear Power Facility Construction. National Conference of State Legislatures. Retrieved February 20, 2023, from https://www.ncsl.org/environment-and-natural-resources/states-restrictions-on-new-nuclear-power-facility-construction  

Nuclear Energy Agency and the International Atomic Energy Agency (NEA). (2020). (rep.). Uranium 2020: Resources, Production and Demand. Retrieved February 23, 2023, from https://www.oecd-nea.org/jcms/pl_52718/uranium-2020-resources-production-and-demand.  

Rusco, F., Marroni, D., Dondoe, M., Benitez, B., Cady, T., Campbell, C., Congdon, T., Dacey, R., Delicath, J., Gilbert, C., Halifax, H., Kendix, M., Kestenbaum, K., McCabe, T., McIntyre, P., Moye, T., Mullan, A., Pekar-Carpenter, K., Royer, D. C., & Sanchez, R. (2021). (rep.). COMMERCIAL SPENT NUCLEAR FUEL Congressional Action Needed to Break Impasse and Develop a Permanent Disposal Solution. U.S. Government Accountability Office (GAO). Retrieved February 20, 2023, from https://www.gao.gov/assets/gao-21-603.pdf 

Scott, M. (2018, May 7). Annual Energy Outlook 2018. EIA. Retrieved February 20, 2023, from https://www.eia.gov/outlooks/aeo/npo.php  

Sepulveda, N. A., Jenkins, J. D., de Sisternes, F. J., & Lester, R. K. (2018). The role of firm low-carbon electricity resources in deep decarbonization of power generation. Joule, 2(11), 2403–2420. https://doi.org/10.1016/j.joule.2018.08.006  

Shea, D. (2017, May 30). State Options to Keep Nuclear in the Energy Mix. National Conference of State Legislatures. Retrieved January 18, 2022, from https://www.ncsl.org/energy/state-options-to-keep-nuclear-in-the-energy-mix  

Southern Company (SC). (n.d.). Building carbon-free nuclear energy Plant Vogtle Units 3 and 4 . Southern Company. Retrieved February 20, 2023, from https://www.southerncompany.com/innovation/vogtle-3-and-4.html  

Sovacool, B. K., Andersen, R., Sorensen, S., Sorensen, K., Tienda, V., Vainorius, A., Schirach, O. M., & Bjørn-Thygesen, F. (2016). Balancing safety with sustainability: Assessing the risk of accidents for modern low-carbon energy systems. Journal of Cleaner Production, 112, 3952–3965. https://doi.org/10.1016/j.jclepro.2015.07.059  

Suman, S. (2018). Hybrid Nuclear-Renewable Energy Systems: A Review. Journal of Cleaner Production, 181, 166–177. https://doi.org/10.1016/j.jclepro.2018.01.262  

U.S. Department of Energy (DOE). (n.d.). Nuclear. Energy.gov. Retrieved February 21, 2023, from https://www.energy.gov/nuclear   

U.S. Department of Energy (DOE). (2023, January 20). NRC certifies first U.S. Small Modular Reactor Design. Energy.gov. Retrieved February 23, 2023, from https://www.energy.gov/ne/articles/nrc-certifies-first-us-small-modular-reactor-design  

U.S. Energy Information Administration (EIA). (2012, August 17). Electric generator dispatch depends on system demand and the relative cost of operation. eia. Retrieved February 21, 2023, from https://www.eia.gov/todayinenergy/detail.php?id=7590   

U.S. Energy Information Administration (EIA). (2021, December 17). Nuclear Explained - Nuclear power and the environment. U.S. Energy Information Administration - Independent Statistics & Analysis. Retrieved January 18, 2022, from https://www.eia.gov/energyexplained/nuclear/nuclear-power-and-the-environment.php  

U.S. Energy Information Administration (EIA). (2022, June 16). Missouri Profile Analysis. EIA. Retrieved February 20, 2023, from https://www.eia.gov/state/analysis.php?sid=MO  

U.S. Government Accountability Office, Commercial Spent Nuclear Fuel: Congressional Action Needed to Break Impasse and Develop a Permanent Disposal Solution (2021). Retrieved January 18, 2022, from https://www.gao.gov/products/gao-21-603 

U.S. Nuclear Regulatory Commission (NRC). (n.d.). Storage of spent nuclear fuel. U.S. NRC. Retrieved February 21, 2023, from https://www.nrc.gov/waste/spent-fuel-storage.html  

U.S. Nuclear Regulatory Commission (NRC). (2019, July 23). Backgrounder on Radioactive Waste. United States Nuclear Regulatory Commission - Protecting People and the Environment. Retrieved January 18, 2022, from https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/radwaste.html  

U.S. Nuclear Regulatory Commission (NRC). (2020, March 19). What is plutonium? . United States Nuclear Regulatory Commission - Protecting People and the Environment. Retrieved January 19, 2022, from https://www.nrc.gov/reading-rm/basic-ref/students/science-101/what-is-plutonium.html  

World Health Organization (WHO). (2005, September 5). Chernobyl: The True Scale of the accident. World Health Organization. Retrieved January 19, 2022, from https://www.who.int/news/item/05-09-2005-chernobyl-the-true-scale-of-the-accident 


**This Note has been updated since its original publication. Previous versions are not up-to-date, but can be accessed here: Version 1 (October 2020) and Version 2 (January 2022).

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