Is Nuclear Power A Green Energy?

Nuclear power has often been touted as a clean and green energy source that can help mitigate climate change. However, the debate continues on whether nuclear truly qualifies as a “green” energy. There are arguments on both sides – some highlighting the low carbon emissions, others focusing on radioactive waste and safety issues. This article will examine the pros and cons to determine whether nuclear power meets the criteria to be considered a green and sustainable energy source.

Nuclear Power Basics

Nuclear power plants work by harnessing the heat generated from nuclear fission reactions taking place inside a nuclear reactor. Inside the reactor, uranium fuel rods are submerged in water. The uranium atoms split when bombarded by neutrons, producing a large amount of heat as well as more neutrons to continue the fission reaction. Control rods absorb excess neutrons to regulate the rate of fission. The heat from the nuclear reaction turns the surrounding water into steam, which then spins a turbine to generate electricity.

The two main fuel sources for nuclear power plants are uranium-235 and plutonium-239. Uranium-235 is a naturally occurring isotope, but only makes up about 0.7% of natural uranium. The rest is non-fissile uranium-238. Nuclear fuel is enriched to increase the proportion of uranium-235. Plutonium-239 is produced from uranium-238 through neutron capture and subsequent radioactive decay. Both uranium-235 and plutonium-239 readily undergo nuclear fission when hit by neutrons.


Carbon Emissions

Nuclear power plants emit extremely low amounts of carbon emissions during electricity generation. According to the U.S. Energy Information Administration, nuclear reactors do not produce any direct carbon dioxide emissions during operation [1]. This gives nuclear power a key advantage over fossil fuel plants, which contribute significantly to greenhouse gas emissions and climate change.

The World Nuclear Association states that nuclear energy produces about the same amount of carbon emissions as wind and solar power across the entire lifecycle – from mining uranium to plant decommissioning. Nuclear emits 50 times less carbon emissions per kWh than coal plants, and 30 times less than natural gas [2]. According to the Grantham Institute, nuclear energy’s carbon footprint is around 15-50 grams of CO2 per kilowatt hour. In comparison, coal emits around 800-900 gCO2/kWh [3].

With virtually no direct emissions, nuclear power is one of the most viable low-carbon energy sources available today. Its minimal life-cycle emissions give nuclear a significant advantage over fossil fuels in reducing greenhouse gas emissions.

Waste Management

One of the major concerns with nuclear power is the generation of radioactive waste. According to the World Nuclear Association, nuclear waste is produced at all stages of the nuclear fuel cycle, including mining, fuel fabrication, electricity generation, and plant decommissioning. The most hazardous and volatile waste is the used nuclear fuel discharged from reactors, which is extremely radioactive and requires careful treatment and isolation from the environment.

a nuclear power plant generating electricity.

Currently, most used fuel is stored on-site at nuclear plants, awaiting permanent disposal. But permanent underground repositories for nuclear waste are still under development, with only one operating globally in Finland. The lack of long-term storage has led to a build-up of nuclear waste at sites around the world. For example, according to the U.S. Government Accountability Office, over 80,000 metric tons of spent nuclear fuel is stored at commercial nuclear power plants across the country. Without a permanent disposal site, this waste must be carefully monitored and stored securely to avoid environmental contamination.

Developing safe, long-term solutions for nuclear waste storage and disposal is a key challenge facing the nuclear industry. Overcoming issues around nuclear waste management will be important for the future viability and sustainability of nuclear power.

Safety Record

Nuclear power plants have a very good safety record overall. There have been only three major nuclear accidents in the history of civil nuclear power – Three Mile Island, Chernobyl and Fukushima. Of these, only Chernobyl resulted in radiation-related fatalities. The evidence shows that the chance of experiencing a major nuclear accident within a nuclear plant’s lifespan is low and declining (Our World in Data).

According to the World Nuclear Association, the impacts of even major nuclear accidents have been far less severe than widely feared. They report the death rate from nuclear power since 1965 as 1.3 deaths per terawatt-hour (TWh). This rate is dominated by Chernobyl, and compares very favorably to death rates from coal and hydroelectricity (World Nuclear Association).

Modern nuclear reactors have multiple redundant safety systems in place to prevent accidents and radiation leaks. They are designed to shut down safely in the event of equipment failure or human error. Studies show the risk of accidents and radiation exposure is very low compared to other major electricity sources (World Nuclear Association).


Nuclear power plants have very high upfront costs, but relatively low operating costs.1 The capital costs for a new 2200 MWe nuclear power plant could range from $7,675 to $12,500 per kilowatt.2 Once built, nuclear plants have low fuel costs relative to fossil fuel plants. However, the initial construction costs make nuclear less economically competitive with other sources like natural gas and renewables.

Operating costs for nuclear plants are also comparatively low at around 0.5 cents per kWh, lower than coal and natural gas plants.3 This makes existing nuclear plants economically competitive as base load sources of electricity. But the staggering construction costs of over $5 billion for a large nuclear reactor create a high barrier to building new plants.


One concern about nuclear power is the availability of uranium to fuel nuclear reactors. Uranium is a non-renewable resource, so there are finite amounts available on earth. However, according to Scientific American, seawater extraction could provide a 60,000 year supply of uranium at current usage rates. The world’s known uranium resources have also increased significantly in recent decades as more deposits are discovered through mineral exploration (Supply of Uranium).

Furthermore, advanced reactor designs like breeder reactors can extend uranium supplies dramatically. Breeder reactors utilize uranium-238 for fuel, which makes up over 99% of natural uranium. This isotope could power breeder reactors for billions of years (Nuclear fuel will last us for 4 billion years). So while uranium is a finite resource, supplies are abundant enough to power nuclear reactors for the foreseeable future.

Proliferation Risks

One of the main concerns with nuclear power is the potential for weapons proliferation. According to the Arms Control Center, “the key risk lies with the nuclear fuel cycle because facilities and technologies used in the enrichment and reprocessing of nuclear fuel can also be used to produce fissile material for nuclear weapons” (Arms Control Center). Enrichment and reprocessing allow countries to generate weapons-grade uranium and plutonium. Panofsky argues nuclear proliferation risks are perhaps the most threatening, as efforts to combat them have been slow and distorted by politics (Panofsky). The effects of nuclear weapons cannot be contained within borders, posing risks globally according to the ICRC (ICRC). Overall, the potential for nuclear weapons proliferation is a serious downside of nuclear power that must be addressed through strict safeguards and non-proliferation policies.


Other low-carbon energy sources like renewable power from solar, wind, hydroelectric, geothermal, and biomass offer an alternative to nuclear power. Renewables like solar and wind energy are considered “green” energy sources since they do not produce greenhouse gas emissions during operation. The costs of renewable energy have also been rapidly declining, making them more economically competitive with nuclear power.

However, renewable sources are intermittent and weather-dependent, so energy storage or backup power is needed to ensure reliable electricity supply. Some argue that an “all of the above” energy strategy utilizing both renewables and nuclear is required to fully decarbonize the power sector. Ultimately, each source has pros and cons, and most experts agree a diverse mix of low-carbon energy will be needed to address climate change.


In conclusion, the case for nuclear power being considered a “green” energy source is complex. On one hand, nuclear plants produce electricity without emitting greenhouse gases or air pollution during operation, making them one of the lowest carbon energy sources available. The small amount of fuel required to produce immense amounts of energy is also often cited as an advantage of nuclear from a sustainability perspective. However, concerns around radioactive waste, safety, weapons proliferation, and costs provide reasonable arguments against nuclear as well. There are also debates around whether the life cycle carbon emissions from mining, enrichment, plant construction and decommissioning may reduce some of nuclear’s carbon advantage. Weighing all the evidence, a cautious case can be made for nuclear as a transitional energy source as we move towards greater shares of renewables, but it is unlikely to satisfy the criteria to be considered fully “green” by many definitions.

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