Nuclear Energy
Nuclear plants make electricity with no direct greenhouse gas emissions, yet Chernobyl and Fukushima still shape energy policy.
By Greg Goodwin · Published July 3, 2026 · Updated October 24, 2026
Cheat Sheet
- Nuclear energy is generated by splitting atomic nuclei in a process called fission, releasing an enormous amount of energy from a relatively small amount of nuclear fuel.
- Nuclear power plants use controlled fission reactions to generate heat, which produces steam that drives turbines to generate electricity, similar in basic structure to many fossil fuel power plants.
- Nuclear energy produces electricity without direct greenhouse gas emissions during operation, a significant factor in ongoing debates about its potential role in addressing climate change.
- Major nuclear accidents, including Chernobyl in 1986 and Fukushima in 2011, significantly shaped public perception and regulatory policy around nuclear energy safety worldwide.
- Nuclear waste, particularly long-lived radioactive material, requires extremely careful long-term storage and management, a significant ongoing technical and political challenge for the nuclear power industry.
- Nuclear fusion, a different nuclear process that combines rather than splits atomic nuclei, is being actively researched as a potential future energy source but remains considerably further from practical large-scale power generation than fission.
The 60-Second Version
Nuclear energy is generated by splitting atomic nuclei in a process called fission, releasing an enormous amount of energy from a relatively small amount of nuclear fuel. Nuclear power plants use controlled fission reactions to generate heat, which produces steam that drives turbines to generate electricity, similar in basic structure to many fossil fuel power plants. Nuclear energy produces electricity without direct greenhouse gas emissions during operation, a significant factor in ongoing debates about its potential role in addressing climate change. Major nuclear accidents, including Chernobyl in 1986 and Fukushima in 2011, significantly shaped public perception and regulatory policy around nuclear energy safety worldwide. Nuclear waste, particularly long-lived radioactive material, requires extremely careful long-term storage and management, a significant ongoing technical and political challenge for the nuclear power industry. Nuclear fusion, a different nuclear process that combines rather than splits atomic nuclei, is being actively researched as a potential future energy source but remains considerably further from practical large-scale power generation than fission.
The Long Version
Splitting Atoms to Generate Enormous Energy
Nuclear energy is produced through fission, the process of splitting the nuclei of certain heavy atoms, most commonly uranium, releasing an enormous amount of energy relative to the small amount of fuel actually consumed, a dramatically higher energy density than conventional fossil fuel combustion requires for an equivalent energy output.
From Fission Reaction to Electricity
Inside a nuclear power plant, controlled fission reactions taking place within the reactor core generate substantial heat, which is used to produce steam that drives turbines connected to electricity generators, a basic structural process actually quite similar to many fossil fuel power plants, with the key difference being the heat source itself.
Zero Direct Emissions, But Real Accident History
Because nuclear power plants don't burn fuel in the conventional combustion sense, they produce electricity without direct greenhouse gas emissions during operation, a significant point in ongoing debates about nuclear energy's potential role in addressing climate change. At the same time, major historical accidents, including Chernobyl in 1986 and Fukushima in 2011, caused significant public concern and reshaped safety regulation and public perception of nuclear energy worldwide, complicating its broader adoption despite its emissions advantages.
The Long-Term Waste Challenge, and Fusion's Distant Promise
Nuclear waste, particularly certain long-lived radioactive materials produced during fission, requires extremely careful long-term storage and management, a significant ongoing technical and political challenge for the nuclear industry that remains unresolved in many countries. Separately, nuclear fusion, which combines rather than splits atomic nuclei, is being actively researched as a potential future energy source offering significant theoretical advantages, but remains considerably further from practical, large-scale commercial power generation than existing fission technology.
Why People Care
Nuclear energy's combination of enormous energy density and zero direct operational emissions makes it a significant part of ongoing debates about how to address climate change, even as its accident history and unresolved waste storage challenges continue to shape public opinion and policy.
Glossary
- Nuclear fission
- The process of splitting atomic nuclei, releasing energy, used in current nuclear power plants.
- Nuclear fusion
- The process of combining atomic nuclei, releasing energy, being actively researched as a potential future energy source.
- Reactor core
- The central part of a nuclear power plant where controlled fission reactions take place.
- Nuclear waste
- Radioactive byproduct material from nuclear power generation, requiring careful long-term storage and management.
- Chernobyl / Fukushima
- Two major nuclear accidents, in 1986 and 2011 respectively, that significantly shaped public perception and safety regulation of nuclear energy.
Go Deeper
More to Explore
- Gravity
The force that keeps you in your chair, the Moon in the sky, and physicists awake at night.
- Optics and Light
Rainbows, eyeglasses, fiber-optic internet, and telescopes all come down to how light bends.
- Fluid Dynamics
We can predict the orbit of a planet centuries ahead, but we still can't fully explain the swirl of smoke rising from a candle.
- The Standard Model of Particle Physics
Physicists predicted the Higgs boson in 1964, then waited until 2012 and a giant collider at CERN to actually catch it.
- Electromagnetism
Light, radio waves, and the current running through a phone charger are, at a fundamental level, all exactly the same physical phenomenon.