Nuclear Energy Overview

In the United States there are 94 operating commercial reactors that represented 20% of the United States energy grid’s generation mix in 2020 (EIA 2021). With climate change issues coming to the forefront recently, focus on non-carbon emitting energy resources like nuclear energy have resurfaced. Understandings the benefits and costs with nuclear energy is important in developing a safe, reliable, and cost-effective decarbonized energy grid.

Greenhouse Gas Emissions

To limit global warming to a 1.5°C above pre-industrial levels, emissions of carbon dioxide would need to reach net zero around 2050 (IPCC 2018). Nuclear energy only generates 3 metric tons of GHGs per gigawatt-hour over the lifecycle of the power plant. Alternatively, wind and solar generate 4 and 5 metric tons per gigawatt-hour respectively, and natural gas and oil generate 490 and 720 (Ritchie 2020). From a lifecycle perspective, nuclear energy produces the least GHGs per gigawatt-hour of electricity and would help reduce the carbon emissions from the energy grid.

Figure 1. Safest and Cleanest Sources of Energy

Source: Ritchie 2020.

Safety Record

Nuclear energy provides large amounts of energy with low risks to human life. Nuclear energy’s estimated death rates from accidents and air pollution are only 0.07 deaths per terawatt-hour. This is much lower than coal, oil, and natural gas that come in at 24.6, 18.4, and 2.8 deaths per terawatt-hour respectively. While nuclear is slightly higher then hydropower, wind, and solar that average together 0.03 deaths per terawatt-hour, nuclear energy’s death rate also includes the Fukushima and Chernobyl disasters where a large amount of those deaths were indirect from evacuation issues (Ritchie 2020). The death rates for nuclear historically have been very low and are comparable to renewable energy resources. Newer reactor technologies like Fast Breeder Reactors (FBR) or Liquid Metal FBRs do not require graphite or water moderators in the core so have less risk of meltdowns disasters as well (IEER 2012).

Waste Characteristics

Nuclear plants generate various severities of nuclear waste that range from very low-level waste (VLLW) to high-level waste (HLW). Over 98% of the waste generated by nuclear power plants are very low or low-level wastes (LLW) as seen in Table 1 below (World Nuclear Association 2021). The majority of this radioactive material can easily be disposed of in near surface landfills or in engineered near surface facilities with minimal risk as it lowers in radioactivity in just a few hundred years (IAEA 2009, 5).

Table 1. Nuclear Waste Inventory (IAEA estimates, 2018)

Source: World Nuclear Association 2021.

People mainly imagine radioactive waste to be the high-level waste that is radioactive for thousands of years. While this waste is much more dangerous and harder to manage, it is mainly a result of once-through fuel cycle reactors. Newer closed fuel cycle or breeder fuel cycle reactors recycle the nuclear material to be used again, reducing the decay time from thousands of years to 300-500 years. Hydrocarbon sources like coal also create radioactive waste and other toxic waste. Nuclear power is one of the few utility-scale energy technologies that has internalized all the costs of these external waste products (World Nuclear Association 2021).


Nuclear has a higher levelized cost of electricity (LCOE) of $69.39 per megawatt-hour when compared to other renewable energy resources like wind and solar at $36.93 and $32.78 respectively (U.S. Energy Information Administration 2021). These higher costs primarily come from the upfront construction costs and the waste management requirements. However, nuclear remains cheaper than coal, combustion turbines, and biomass, indicating that it is a strong economic choice for decarbonizing the energy grid.

Table 2. Value-cost ratio (unweighted) for new resources entering service in 2026

Energy Sustainability

Nuclear power is typically not considered a renewable energy resource like wind and solar because nuclear fuel requires mining of limited resources. However, with breeder reactor technologies that recycle the radioactive materials for maximum use, it is estimated that breeder reactors could power the globe for 4 billion years, nearly as long as the Sun is expected to exist (Touran 2020). Nuclear technology is also an important component of space exploration and its research and investment provides further value to these future-focused industries.

Figure 2. Nuclear Fission Years of Energy

Source: Touran 2020.

Nuclear as an Alternative Energy Resource

While concerns about nuclear energy’s costs and radioactive waste stream are important, the benefits of nuclear energy provide strong use cases for it in decarbonizing the U.S. energy grid. Nuclear energy is safe, reliable, sustainable, and reduces GHG emissions while increasing benefits to other industries. Nuclear energy should be an integral part of the U.S. energy mix, providing necessary baseload energy supply to support intermittent renewable energy resources.

Author: Logan Callen


EIA. 2021. “Nuclear Explained: U.S. Nuclear Industry.” Accessed May 1, 2021.

IAEA. 2009. “IAEA Safety Standards for Protecting People and the Environment.” International Atomic Energy Agency. Accessed May 1, 2021.

IEER. 2012. “Types of Nuclear Reactors.” Institute for Energy and Environmental Research. Accessed May 1, 2021.

IPCC. 2018. “Summary for Policymakers.” IPCC. Accessed May 1, 2021.

Ritchie, Hannah. 2020. “What are the Safest and Cleanest Sources of Energy?” Our World In Data. Accessed May 1, 2021.

Touran, Nick. 2020. “Nuclear Fuel Will Last Us for 4 Billion Years.” What Is Nuclear. Accessed May 1, 2021.

U.S. Energy Information Administration. 2021. “Levelized Costs of New Generation Resources in the Annual Energy Outlook 2021.” EIA. Accessed April 28, 2021.

World Nuclear Association. 2021. “Radioactive Waste Management.” World Nuclear Association. Accessed May 1, 2021.

0 comments on “Nuclear Energy OverviewAdd yours →

Leave a Reply

Your email address will not be published. Required fields are marked *

Accessibility Toolbar