Introduction to Nuclear Energy

An icon of a
  nuclear reactor with an atom symbol on a cooling tower and a lightning bolt on
  the reactor.

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Slides courtesy of


Context and issues

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Energy gives us freedom

It is a substitute for labor and time

Quality of life is correlated with energy use

Plot by A. Alhajri


Fossil fuels powered modernity

  • Iron, copper, steel, concrete
  • Fertilizer
  • Railroads
  • Global health
  • Moon landing
  • Internet
  • Chihuly

Coal saved the forests of Europe from being decimated for charcoal.

The National Academy of Engineering chose electrification as the top innovation of the 20th century.

But, fossil fuel (and biofuel) cause air pollution

The WHO estimates 7 million premature deaths due to combustion of dirty indoor biofuel and outdoor fossil fuel

And climate change


Fortunately, we have low-carbon sources


What is


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Atoms have protons, neutrons, and electrons (derived from BruceBlaus)


Three isotopes of hydrogen (Balajijagadesh)

The first few rows of the Chart of the Nuclides (National Nuclear Data Center)

Chart of the Nuclides zoomed out (National Nuclear Data Center)

Nuclei can undergo spontaneous or induced nuclear reactions, like these (CC-BY-SA LibreTexts)

Nuclear fission: nucleus splits apart (MikeRun)

Fission yields from fissioning U-235 (National Nuclear Data Center)

Marie Curie pioneered nuclear chemistry and coined the term 'radioactive' (1898)

Ida Noddack correctly hypothesized fission based on an experiment (1934)

Lise Meitner was instrumental in confirming nuclear fission (1938)


Nuclear fusion: nuclei pushed together (src)

Key nuclear reactions for energy

(splitting large)
(combining small)
In nature Georeactors in Oklo, Gabon The stars and Sun
Discovered 1938 1932
1st chain reaction 1942 at CP-1 1951 George shot
Weaponized 1945 Trinity shot 1951 George shot
Made electricity 1951 at EBR-1 Working on it
Propulsion 1955 on USS Nautilus N/A
Powered ice base 1960 at Camp Century N/A
In space 1965 on SNAP-10A N/A
Competitive power 1965 Oyster Creek Thinking about it
In 2023 Makes 10% of world electricity In development

How a



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Eta Carinae (NASA/ESA)

Uranium ore (Geomartin)

Yellowcake (IAEA)

Isotopic concentrations (whatisnuclear)

Gas centrifuges (GAO-18-126)

Nuclear fuel pellets (NRC)

Fuel assembly (NRC)

Reactor core refueling (D.C. Cook)

A neutron chain reaction

A Pressurized Water Reactor (TVA)

Spent fuel pool (NRC)

A dry cask (@ParisOrtizWines)

Swedish KBS-3 capsule for nuclear waste


of nuclear power

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In 2022, nuclear fission made:

  • 4.2% of world energy
  • 10% of world electricity
  • 22% of US electricity
  • 55% of US low-carbon electricity

There are ~437 power reactors in operation (Carbon Brief)

Global capacity changes (Carbon Brief)

France went all-in on nuclear (@whatisnuclear)

We've gotten extremely good at running nuclear plants

Fraction of the time the plant is running at full capacity (

Nuclear plants can load follow at around 40 MW per minute!

Technical and Economic Aspects of Load Following with Nuclear Power Plants (OECD-NEA)

Nuclear plants can load follow at around 40 MW per minute!

Technical and Economic Aspects of Load Following with Nuclear Power Plants (OECD-NEA)

Barakah: 4 APR-1400s in UAE

  • Started with proven design
  • Brought in Korean workforce
  • Went from 0 to APR-1400 in 10 years
  • Now offering world's first green certificates for nuclear-powered aluminum plant

Used with permission from @AngelicaOung

Hualong One

  • "China Dragon 1"
  • Developed by CGN and CNNC
  • 3-loop PWR
  • Approved by European Utility Requirements and UK GDA
  • 5 operational, 11 under construction as of Jan 2024
  • ~5 years to construct

Hualong One CC-BY-4.0 Ji Xing


  • $1,200/kW overnight construction cost
  • 54 month construction time
  • 34.8% net thermal efficiency
  • Being exported broadly
  • Foreign projects often financed by Russian govt

Manufacturing a VVER-1000 RIA Novosti Archive CC-BY-SA 3.0

Westinghouse AP-1000

  • Up-rated from original AP-600 design for economy of scale
  • Vogtle units 3 & 4 first nuclear plants to start construction in US since 1978
  • Boondoggled
  • Unit 3 entered commercial operation in 2023!
  • Construction started in 2013
  • Related VC Summer project cancelled, riddled in scandal

Vogtle Unit 3 (NRC)


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Fuel nuclides

  • Uranium consumer
  • Uranium-Plutonium breeder
  • Thorium-Uranium breeder
  • Plutonium consumer

Fuel cycles

  • Once-through
  • Single recycling
  • Full recycling

Fuel forms

  • Oxide
  • Carbide
  • Nitride
  • Metal (solid or molten)
  • Molten salt


  • Water
  • Heavy water
  • Liquid metal
    • Sodium/NaK
    • Lead/PbBi
  • Gas
    • Air
    • Nitrogen
    • CO₂
    • Helium
  • Organics (Terphenyl)
  • Molten salt
    • Fluoride
    • Chloride
  • Liquid Hydrogen
  • Heat pipes


  • Water
  • Heavy water
  • Graphite
  • Unmoderated (fast reactor)
  • Beryllium
  • Organics
  • Hydrogen/hydride

Power cycles

  • Rankine
  • Brayton
  • Stirling
  • Piston
  • Chemical
  • Thermionic
  • ...

Other design parameters

Size/Power level

  • Micro
  • Small
  • Medium
  • Large
  • Gargantuan


  • Land
  • Sea (surface)
  • Sea (submerged)
  • Air
  • Space
  • Ice base

Construction method

  • Stick-built
  • Factory-built modules
  • Factory-built reactor
  • Hybrid

The whatisnuclear random reactor generator


of nuclear energy besides central power stations

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Submarines and carriers (US Navy)

Merchant shipping (USG)

Space travel (LANL)

District heat

District heat in Switzerland (Axpo)

China is making nuclear district heat (WNN)

Making special radionuclides

Lutetium-177 treatment of metastatic prostate cancer (ref)

“This day marks a paradigm shift in medical isotope supply wherein the international medical community can now depend on scalable, reliable, Canadian, power-reactor produced isotopes for their cancer treatments.” -- David Harris

Remote power

Mars rover (NASA)

Small fission power prototype for moon base (NASA)

ML-1 portable reactor (AEC)


Nuclear desalination options (Khamis, IAEA)

A nuclear-powered agro-industrial complex (AEC)


What about


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Nuclear waste is composed of nuclei left over after neutron irradiation

Most of the energy of fission comes out immediately, but some comes out later

The energy comes out on different time scales

Magil 2003

How much waste is there?

If all US nuclear waste were loaded into dry casks, it would stack this high (

Nuclear waste solution options

  • On-site dry cask storage
  • Interim consolidated dry cask storage
  • Deep geologic repository
    • Mined repository
      • Rock (e.g. Onkalo, KBS-3, Yucca Mtn.)
      • Salt formations (e.g. WIPP)
    • Deep borehole
  • Recycling/reprocessing

Operational nuclear waste repository in salt at WIPP (DOE)

Finland's Onkalo repository (Posiva)

Nuclear waste disposal is already paid for by rate payers

  • In the US, the 1982 Nuclear Waste Policy Act set up a Nuclear Waste Fund
  • All commercial plants paid 1.0 mill per kWh generated
  • Current balance is about $55 billion
  • Payments were suspended in 2014 because repository stalled
  • Research and construction for Yucca Mountain spent about $10 B
  • Similar funds in Canada, Germany, Finland, etc.

A 2020 audit report of the Nuclear Waste fund (DOE)

So what's the problem? No one wants it.

Anti-nuclear organizations oppose proposed solutions

Pushing back against waste solutions is documented policy

Strategy document from a 500-person meeting opposing nuclear power in 1991 including Ralph Nader, Amory Lovins, etc. (from Atomic Insights)

Going forward on waste

  • Onkalo will clearly demonstrate the solution (if WIPP hasn't)
  • Consent-based siting efforts may make progress
  • Need to find out how to get communities to reach out as repository host
  • Challenge anti-nuclear organizations who oppose solutions
    • Inconsistency: You can't simultaneously consider waste horrifying while stone-walling its safe disposal.
  • Alternate: recycling
    • Required for 1000+ year sustainability
    • Still needs repository for process losses and long-lived FPs
    • Far more expensive, and we need to make nuclear power cheaper
    • Historical proliferation issues ("plutonium!")

Here's a more positive view of nuclear waste (Photo from NRC)



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Afterglow heat is the key safety challenge

Reactor power does not go to zero when the chain reaction is stopped (

Nuclear has proven to be among the safest and cleanest forms of energy

From Our World in Data

By 2013, nuclear power had prevented 1.8 million premature deaths and 64 billion tonnes of CO₂ emissions

Kharecha and Hansen (NASA Goddard Institute)

If that's not safe enough, there are other reactor design options


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What advances have occurred?

  • The existing fleet gained operational experience. Next-generation models of the same type incorporated the lessons.
  • World energy context changed enough for previous non-water concepts to gain new interest
  • New technology was developed that can be incorporated into new designs

Advanced reactors today intend to solve contemporary problems

  • Natural safety without backup systems
  • More practical to finance (smaller)
  • Decarbonize hard-to-decarbonize sectors
    • Industry
    • Shipping
  • World-scale million-year+ sustainability (breeding)
  • Waste processing/reduction


  • There are lessons to be learned in initial construction and scaling
  • New reactor development is hard and slow

A small reactor (ANL)

Advanced water-cooled reactors

Based on proven, well-known technology

  • Advanced large LWRs
    • Modular construction
    • Simplified systems
    • 72 hours without backup power
    • Digital instrumentation and control
    • ABWR, AP-600, AP-1000, APR-1400, Hualong 1, VVER
  • Small water-cooled reactors
    • Modular delivery and/or construction
    • Depends on economies of mass production exceeding economies of scale

An AP1000 advanced reactor (Westinghouse)

Fast-neutron reactors

Reactors that don't include a moderator


  • World-scale sustainability
  • Waste processing/reduction
  • Natural safety
  • High thermal efficiency
  • Industrial heat


  • Higher fissile concentration
  • Chemically reactive coolants
  • Extra costs from extra coolant loops
  • Plutonium scares people

Fast reactor history (adapted from Walter, Fast Breeder Reactors)

Breeder reactors are necessary in the long run

Breeder reactors are as renewable as anything else (

Thorium reactors

Breeder reactors that don't need fast neutrons

  • Plentiful in India and China
  • Used in Indian Point initial core
  • Works well with fluid-fuel reactors
  • China about to turn on a new experimental Thorium Molten Salt Reactor called TMSR-LF1
  • Does not completely eliminate proliferation or waste issues

A fluid fueled reactor (ARE)

Fusion Power Plants

  • Much less radioactive waste
  • No afterglow heat to cool
  • Many highly-funded startups catching headlines
  • Extremely challenging physics
  • Unknown power conversion
  • Often necessitates tritium breeding
  • Often a powerful neutron source
  • Worth investigating, but lets not rely on it


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Historical construction costs (Lovering, 2016)

The UAE just built 4 large LWRs (IAEA, 2021)

Project Delivery is key

  • Difference in good vs. bad project dwarfs design particulars
  • France and S. Korea show us how to do it: standardization
  • Reactor assembly line
  • Shipyard-constructed reactors (see Offshore Power Systems)
  • Suggestions to reduce cost

    • Complete detailed design prior to construction
    • Use proven supply chain and skilled workforce
    • Incorporate manufacturers and builders into design teams early
    • Appoint single primary contract manager with experience
    • Use contract structure that aligns all actors with project success
    • Enable a flexible regulatory environment that can accommodate changes quickly.
    • Do more serial manufacturing of standardized plants
    • Use inherent and passive safety features
    • Incorporate CO₂ into the cost of energy
    • Governments should establish reactor sites where companies can deploy prototypes
    • Governments should fund prototype testing and commercial deployment via licensing cost share, R&D cost share, technology milestone funding, and production credits for successful demonstration of new designs

    The Future of Nuclear in a Carbon-Constrained world (2018)

    Ok, but


    given the progress in wind and solar?

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    Nuclear has proven decarbonization at scale



    (NYT 2020-02-03)

    (Sepulveda, 2018)

    Indian Point was replaced with fossil (Nuclear NY)


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    Save Clean Energy rally in SLO last November organized by Isabelle Boemeke (@IsabelleBoemeke)

    Things you can do

  • Push for technology-inclusive policies that promote low-carbon energy regardless of labels (prefer 'clean/low-carbon' over 'renewable')
  • Join a grassroots nuclear organization like Generation Atomic
  • Reject fracked methane as an acceptable option for backing up your renewables
  • Don't let the dubious concept of LCOE satisfy you for economics. Demand full system costs.
  • Help us figure out how to do consent-based siting of nuclear waste repositories
  • Talk to your friends, families, and teachers about nuclear
  • Buy a Geiger counter and set it on your granite countertop or take it on a flight

    Find more info and contact form at