Nuclear Fission
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Our 10-Minute Take
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Before You Watch Our Lecture
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Our Lecture
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Additional Resources
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Fast Facts About
Nuclear Fission
Principal Energy Use: Electricity
Form of Energy: Nuclear
Nuclear fission is the process of splitting a large atom into two smaller atoms and releasing a LOT of heat. That heat is used to boil water, make steam, turn a turbine and generator, and produce electricity. Most nuclear power plants today are fueled by enriched uranium 235 to produce non-renewable, carbon-free, 24/7 electricity. The byproducts of nuclear fission are highly radioactive and must be secured away from people for hundreds of thousands of years. There are currently no proven long-term solutions for storage of this radioactive waste.
Nuclear power plants have been operating commercially since the 1950s and tend to be large-scale (1-2 GW). The risk of accidents is low, but the consequences of a nuclear power plant accident have the potential to be extremely severe. Due to the complexity of containing the nuclear reaction and the need for redundant safety systems, capital and operating costs tend to be high and there are long lead times for planning and construction. New technologies known as small modular reactors (SMRs) are being developed in the hopes of offering cheaper and safer alternatives to traditional fission reactors.
The roots of nuclear fission power come from defense. The commercial nuclear industry in the US was born in response to the horror of the destruction from the bombs dropped on Japan at the end of WWII. In the US, the nuclear industry is the only energy industry which has its own governmental agency (the Nuclear Regulatory Commission - NRC), and nuclear-related activities account for ~75% of the US Department of Energy’s budget.
Significance
Energy Mix
4% of world 🌎
(#6 resource)
9% of US 🇺🇸
(#4 resource)
Electricity Generation
9% of world 🌎
(#4 resource)
19% of US 🇺🇸
(#2 resource)
Number of Nuclear Reactors*
World 440 🌎
US 94 🇺🇸
France 56 🇫🇷
China 56 🇨🇳
Change in Global Nuclear Electricity Generation
Increase:
⬆1%
(2018-2023)
*Many nuclear power plants have multiple reactors
Most Uranium Production
Kazakhstan 43% 🇰🇿
of the world’s uranium production from mines
Global Uranium Sources
Uranium mines 90%
Recycling/stock piles 10%
Energy Density of Uranium
33,000x more energy dense than oil
37,000,000x more energy dense than natural gas
Uranium Enrichment
Power plant grade enrichment requirement 3-5%
Weapons grade enrichment requirement 90%
World
Most Electricity Generation
US 30% 🇺🇸
of global nuclear electricity
Highest Penetration
France 65% 🇫🇷
Slovakia 62% 🇸🇰
of country’s electricity generation comes from nuclear
Average Age of Reactors
World 31 years 🌎
US 42 years 🇺🇸
France 37 years 🇫🇷
China 10 years 🇨🇳
Share of New Global Nuclear Capacity Additions
China 36% 🇨🇳
South Korea 14% 🇰🇷
UAE 14% 🇦🇪
(2018-2023)
US
Most Electricity Generation
Illinois 13%
of US nuclear electricity
Highest Penetration
New Hampshire 64%
South Carolina 59%
Illinois 55%
Tennessee 51%
of state's electricity comes from nuclear
Nuclear Installations are Old and Not Competitive
19 US reactors retired
in the last 30 years
New Nuclear is Expensive and Takes a Long Time to Build
4 US reactors added
in the last 30 years
The two most recent reactors took 11 years and cost more than $30 billion (originally expected to cost $14 billion)
Half Lives* of Main Radioactive Nuclear Waste Isotopes
Strontium-90: 29 years
Cesium-137: 30 years
Plutonium-239: 24,000 years**
Amount of Global Nuclear Waste
390,000 metric tons
(about the same weight as the Empire State Building)
10,000 metric tons
generated annually
Methods for Nuclear Waste Storage
- Temporary: pools (~10 years); dry casks (<100 years)
- Recycle the fuel (reduces overall amount of nuclear waste)
- Bury the waste in a geologically safe location***
No proven method to store for 200,000+ years
*Half life is the time taken for the radioactivity of an isotope to be reduced by half
**Plutonium has the potential to be weaponized
***Not yet proven, still in research phase
Drivers
- No direct carbon or air emissions
- Reliable baseload source of low-carbon electricity
- Nuclear power plants have high capacity factors (90-95% in the US)
- Extremely energy dense fuel
- Facilities require relatively low land use
- Uranium is an abundant resource
- Investment and growing interest in small modular reactors
Barriers
- High-risk (extreme consequence x low probability) accidents
- Produces radioactive waste that must be safely stored for hundreds of thousands of years
- Risk of nuclear proliferation and the spread of nuclear weapons capabilities to more countries, with geopolitical consequences
- Rigid baseload on the grid and not flexible for integration of renewables or load following
- Extremely expensive to build and insure relative to other sources of electricity
- Nuclear power plants take a long time to plan, permit, and build, particularly in the United States
- US nuclear power plants are old and require upgrades and new licensing
- Decommissioning of nuclear power plants can take 50+ years and is expensive
- NIMBY* - community opposition to siting nuclear power plants and waste repositories
- Operations are water intensive
- Uranium mines can contaminate water
- Nuclear fuel (and waste byproducts) must be secured and safely transported
- Negative public perceptions of nuclear power, particularly after major nuclear accidents (Chernobyl, Three Mile Island, Fukushima)
*NIMBY - not in my backyard
Climate Impact:
Low
- Near-zero greenhouse emissions when operating
Environmental Impact:
Low to Medium
- Radioactive waste is toxic for hundreds of thousands of years
- Risk of radiation leaks from nuclear meltdowns
- Accidents from transporting nuclear fuel or radioactive waste byproducts
- Nuclear proliferation raises the risk of nuclear weapons use
- Significant environmental impact if atomic weapons or dirty bombs are detonated
- Large amounts of water used for cooling, thermal pollution of water
Our 10-Minute Take On
Nuclear Fission
If you're short on time, start by watching this video of key highlights from our Nuclear Fission lecture.
Presented by: Diana Gragg, PhD; Core Lecturer, Civil and Environmental Engineering, Stanford University; Explore Energy Managing Director, Precourt Institute for Energy
Recorded: February 23, 2022
Duration: 10 minutes
Before You Watch Our Lecture on
Nuclear Fission
We assign videos and readings to our Stanford students as pre-work for each lecture to help contextualize the lecture content. We strongly encourage you to review the Essential videos and readings below before watching our lecture on Nuclear Fission. Include selections from the Optional and Useful list based on your interests and available time.
Essential
- Is Nuclear Power Good or Bad?. The Good Stuff. January 14, 2016. (14 min)
Describes how nuclear power works and weighs the pros and cons of nuclear power. - Uranium. NEED.org. 2023. (4 pages)
An excellent introductory overview of uranium and nuclear energy. - Spent Fuel Storage at Diablo Canyon Power Plant. PG&E. October 1, 2011. (11 min)
Shows the process of taking used fuel from spent fuel pools located inside the Diablo Canyon Power Plant's fuel handling building and transporting the used fuel to the on-site dry storage facility. - 88,000 Tons of Radioactive Waste - And Nowhere to Put It. Verge Science. August 28, 2018. (8 min)
A visit to San Onofre, a retired beachside nuclear power plant near San Diego, California, where nuclear waste is stored on-site. - U.S. Approves First Small Nuclear Reactor Design. Science Friday. February 3, 2023. (17 min)
A discussion of the first small-modular nuclear reactor design approved by U.S. Nuclear Regulatory Commission and what the future of nuclear energy might hold.
Optional and Useful
- Why Nuclear Energy Is on the Verge of a Renaissance. CNBC. June 7, 2022. (21 min)
A dive into nuclear energy’s potential renaissance as a response to the growing crisis of climate change. - 3 Things to Know About Spent Nuclear Fuel Dry Cask Storage. US Department of Energy. February 20, 2024. (1 min)
Shows how spent nuclear fuel is stored in the US. - Michigan Nuclear Plant Aims to be First Even to Reopen in US. Canary Media. March 28. 2024. (1 page)
Describes the unprecedented plan to restart a shuttered nuclear plant in the US. - Nuclear Reactor Restarts in Japan Have Reduced LNG Imports for Electricity Generation. EIA Today in Energy. February 8, 2024. (1 page)
Describes the situation for nuclear reactors in Japan after the Fukushima accident and how nuclear continues to reduce Japan's reliance on LNG imports. - Small Modular Reactors. Are They Now Unavoidable?. Just Have a Think. July 12, 2020. (16 min)
Considers the pros and cons of small modular reactors. - The Eyes of Nye - Nuclear Energy. ThinkForYourself. October 21, 2014. (25 min)
Bill Nye looks into the problem of nuclear waste and whether or not science and society have a solution. - The Fight to Rethink (And Reinvent) Nuclear Power. Vox. May 17, 2017. (8 min)
Conversations with experts, scientists, thought leaders and activists regarding the pros and cons of nuclear power. - How Is Uranium Mining Conducted in the United States?. NEI. July 11, 2012. (5 min)
Describes how uranium is mined to provide fuel for U.S. nuclear energy facilities and where the uranium comes from. - How Nuclear Energy Works. ENECEducation. December 30, 2009. (5 min)
A detailed overview of how a nuclear power plant works. - Where Our Uranium Comes From. EIA. July 7, 2022. (1 page)
A basic overview of where the uranium used by U.S. nuclear power plants comes from. - How Two Cutting Edge US Nuclear Projects Bankrupted Westinghouse. Reuters. May 2, 2017. (3 pages)
Describes challenges the nuclear power industry faces in the United States related to the planning and building of nuclear power facilities, with a spotlight on two nuclear projects that bankrupted Westinghouse in 2017. - In 2019, 9 of the 10 Highest-Generating US Power Plants Were Nuclear Plants. EIA. September 25, 2020. (1 page)
Identifies the top 10 U.S. power plants by electricity generation in 2019. Nine of them were nuclear plants.
Our Lecture on
Nuclear Fission
This is our Stanford University Understand Energy course lecture on nuclear fission. We strongly encourage you to watch the full lecture to understand nuclear fission as an energy system and to be able to put this complex topic into context. For a complete learning experience, we also encourage you to watch / read the Essential videos and readings we assign to our students before watching the lecture.
Presented by: Diana Gragg, PhD; Core Lecturer, Civil and Environmental Engineering, Stanford University; Explore Energy Managing Director, Precourt Institute for Energy
Recorded on: May 1, 2024 Duration: 69 minutes
Additional Resources About
Nuclear Fission
Stanford University
- Stanford Journal of International Relations (Spring 2010) The French Connection: Comparing French and American Civilian Nuclear Energy Programs (a historical perspective)
- Civil and Environmental Engineering Department
- Mark Jacobson - Review/comparison of renewables vs nuclear
- Jack Baker - Reliability of nuclear plants and waste repositories
- Management Science and Engineering Department
- Siegfried Hecker - Nuclear weapons policy and international security
Fast Facts Sources
- US Department of Energy Budget for Nuclear-Related Activities (FY2023 Enacted): US Department of Energy (DOE). Department of Energy FY2024 Budget in Brief Congressional Justification, p 8. March 2023.
- Energy Mix (World 2023): Energy Institute. Statistical Review of World Energy, Primary Energy Consumption by Fuel Type - EJ data table. 2024.
- Energy Mix (US 2023): US Energy Information Administration (EIA). Monthly Energy Review, Energy Overview Table 1.3. April 2024.
- Electricity Mix (World 2023): Energy Institute. Statistical Review of World Energy, Electricity Generation by Fuel - TWh data table. 2024.
- Electricity Mix (US 2023): US Energy Information Administration (EIA). Monthly Energy Review, Electricity Table 7.2a. April 2024.
- Number of Nuclear Reactors (July 2024): World Nuclear Association. World Nuclear Power Reactors & Uranium Requirements. July 17, 2024.
- Change in World Nuclear Energy Generation (2017-2022): Energy Institute. Statistical Review of World Energy, Nuclear Generation - TWh data table. 2024.
- Most Uranium Production (World 2022): World Nuclear Association. World Uranium Mining Production. May 16, 2024.
- Global Uranium Sources: World Nuclear Association. Uranium Markets. May 16, 2024.
- Energy Density of Uranium: Taylor & Francis Group. Layton, Bradley E., Drexel University. A Comparison of Energy Densities of Prevalent Energy Sources in Units of Joules per Cubic Meter.
- Uranium Enrichment: Center for Arms Control and Non-Proliferation. Fact Sheet: Uranium Enrichment: For Peace or For Weapons. August 26, 2021.
- Most Nuclear Electricity Generation (World 2023): Statistical Review of World Energy, Nuclear Generation - TWh data table. 2024.
- Highest Nuclear Power Penetration (World 2023): Ember. Nuclear Overview. May 2024.
- Average Age of Reactors (US April 2024): US Energy Information Administration (EIA). Frequently Asked Questions (FAQs): How Old Are US Nuclear Power Plants, and When Was the Newest One Built?.
- Average Age of Reactors (France May 2024): World Nuclear Association. Nuclear Power in France. May 21, 2024.
- Average Age of Reactors (China June 2024): World Nuclear Association. Reactor Database.
- Share of New Global Nuclear Capacity Additions (World 2018-2023): World Nuclear Association. Reactor Database.
- Most Nuclear Electricity Generation (US 2023): US Energy Information Administration (EIA). Electric Power Monthly, Table 1.9.B. February 2024.
- Highest Nuclear Power Penetration (US April 2024): US Energy Information Administration (EIA). US States: State Profiles and Energy Estimates. July 2024.
- US Nuclear Reactor Retirements and Additions (1994-2024): World Nuclear Association. Reactor Database.
- Timing and Cost of Two Most Recent US Reactor Additions: US Energy Information Administration (EIA). Today in Energy: Plant Vogtle Unit 4 Begins Commercial Operation. May 1, 2024.
- Nuclear Waste Half Lives: US Nuclear Regulatory Commission. Background on Radioactive Waste. January 26, 2024.
- Amount of Global Nuclear Waste: International Atomic Energy Agency. New IAEA Report Presents Global Overview of Radioactive Waste and Spent Fuel Management. January 21, 2022.
More details available on request.
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