Ultraviolet Sun

Fusion is the energy of stars

Fusion is the combination of nuclei to form larger elements

Fission is the splitting of large elements into smaller ones

Why fusion?


  • Minimal Radiation - The reactor walls are the only radioactive byproduct
  • No Meltdowns - Meltdown failures in fission reactors are caused by excess heat, fusion reactors naturally cool down when turned off
  • Nuclear Deproliferation - Fusion fuels are not fissile, meaning they can not be used in nuclear weapons
  • Environmentally Lean & Green - The nuclear energy sector already has a footprint 3x smaller than solar, 18x smaller than natural gas, and 32x smaller than coal
  • Sustainability - Numerous reactions, fuels, and sources that can last billions of years 

Natural Fusion

In order for fusion to occur, an electrostatic force called the coulomb barrier has to be overcome. Think of trying to push two repulsive sides of a magnet together

A substantial amount of kinetic energy is required in order to overcome this repulsion. In the sun, this is achieved through high temperatures and immense gravity

The sun achieves fusion at 15 million °C through a phenomena called quantum tunneling

A nuclei behaves as both a particle and a wave on the quantum scale. It has a small probability to pass through a thin barrier

The high concentration of fuel due to the sun's gravity allows for a suitable amount of reactions to sustain fusion

Quantum Tunneling Example
Illustration of quantum tunneling demonstrating the possibility of particles to pass through a thin barrier [2]
Coulomb Barrier of D-T
D-T fusion requires overcoming the electrostatic repulsion, a thin barrier  [3]


On Earth we can not use gravity to exploit the quantum tunneling phenomena to the extent the sun is able to

Instead we rely on turning up the heat to 150 million °C and using strong magnetic fields to manipulate the nuclei in a plasma state

Or through novel methods such as Bremsstrahlung-irradiating deuterated metals. This method works through reducing the coulomb barrier by masking the fusion fuel in a metal lattice

ITER Tokamak
Illustration of the ITER tokamak reactor, which is a toroidal vacuum chamber being built in France as part of an international experiment [4]
Lattice Confinement Fusion
Illustration of lattice confinement fusion. This technique is new, so check out the NASA publications for more information [5]

The deuterium-tritium (d-t) reaction

The D-T reaction occurs when a deuterium and tritium atom fuse together. It is regarded as the prominent reaction due to its low energy input and high output

Fusion reactions release approximately 4 million times as much energy per unit mass than chemical reactions such as burning coal. Annually, a power plant would require 3 million tons of coal or simply 550 lb of D-T fuel

It is estimated that 66 tons of D-T fuel is needed to meet the US annual energy consumption

Isotopes of Hydrogen
The relevant isotopes of hydrogen [6]
D-T Reaction
Illustration of the D-T reaction [7]


Deuterium, the hydrogen component of heavy water, is formed by the addition of a neutron

Heavy water represents 0.015% of all ocean surface water which is over 10 trillion tons of deuterium

This amount could meet the current US annual energy consumption for upwards of 300 billion years, the epitome of sustainability

deuterium: Heavy water

In order to obtain deuterium, heavy water must be extracted from oceanic water

This can be achieved by the distillation of water, distillation of liquid H2, electrolysis, laser isotope separation, water-hydrogen sulphide exchange, ammonia-hydrogen catalyst exchange, aminomethanehydrogen catalyst exchange, or water-hydrogen catalyst exchange

But water-hydrogen sulphide exchange (Girdler-Sulphide) is the most economical method for the quantity of deuterium needed

This process was well established in Canada between 1980 and 1997 with 4 G-S plants, each producing 500 tons of heavy water annually (100 tons of deuterium)

The resulting heavy water must undergo electrolysis to create oxygen and deuterium gas


Tritium is a hydrogen isotope that is formed by the addition of a neutron to deuterium

Tritium is unstable and decays into helium-3 with a half-life of 12 years, which makes it rare in nature

The tritium atom is radioactive but it can not penetrate more than 6 mm of air, most surfaces, or the outermost layer of skin.

Tritium Example
Tritium is used for low light illumination applications such as gun sights, emergency exit signs, and watches [8]

tritium: Breeding with lithium-6

The lithium-6 isotope, which accounts for 8% of all available lithium, when struck by energized neutrons ejects tritium and helium-4 atoms

It is estimated that first-generation reactors will be able to produce 150 grams of tritium per gigawatt per day by lining the inside of the reactor walls with lithium-6

However, the known worldwide land-based lithium ore reserve will be depleted by 2080 if consumption continues at the projected rate

While the land reserve is only 14 million tons, the oceanic surface water reserve is estimated to be 230 billion tons based on its average concentration of 1.5 ppm. This supply could last upwards of 7 billion years at the current consumption rate

This supply can be ethically tapped by utilizing current-activated membranes to produce a concentration of lithium

tritium: fission waste

Nuclear fission reactors that utilize heavy water as their coolant medium produce a combined 20 kg of tritium annually as a byproduct. Only 8% of reactors use heavy water and this is an incentive for future reactors to be designed as such

The US generates 2,000 tons of spent fission fuel each year and over 80,000 tons is currently in storage. This waste could be utilized in conjunction with lithium-6 to breed tritium outside of fusion reactors

tritium: active generation with d-d

The most sustainable method to relieving the tritium bottleneck is the utilization of deuterium-deuterium fusion reactions

When reacting D-D, tritium and helium-3 atoms are produced. The helium-3 could be further reacted to release tritium and energy, but first generation reactors will likely not be operating at the temperature required for D-He3 fusion

The primary challenge for D-D reactions will be maintaining stable ignition due to the low energy output. Think of holding a match to a twig; eventually, the twig will ignite and no longer require the input energy of the match

Prominent Fusion Reactions
Fuel Input Output Product Energy Release
D + D (50%) Helium-3 3.2 MeV
D + D (50%) Tritium
4.0 MeV
D + T Helium-4 17.6 MeV
D + He-3 Helium-4 18.3 MeV
Li-6 + neutron Helium-4 + Tritium 4.8 MeV

Methodology & Sources

Last Updated: December 9th, 2020

This article identifies deuterium-tritium fuel sources and their extraction methods through the comparison of over a dozen research articles and publications from internationally recognized organizations. It seeks to tie together the fuel to fusion manufacturing chain. Preference is given to publications that obtained data through experimental methods and experience from decades of operation.

  1. "Ultraviolet Sun" - NASA/STEREO - https://www.nasa.gov/image-feature/stereo-a-spacecraft-returns-data-from-the-far-side-of-the-sun
  2. https://toutestquantique.fr/en/tunnel-effect/
  3. https://upload.wikimedia.org/wikipedia/commons/f/fb/Nuclear_fusion_forces_diagram.svg
  4. https://www.iter.org/album/Media/7%20-%20Technical
  5. https://www1.grc.nasa.gov/space/science/lattice-confinement-fusion/
  6. https://en.wikipedia.org/wiki/Isotopes_of_hydrogen#/media/File:Hydrogen_Deuterium_Tritium_Nuclei_Schmatic-en.svg
  7. http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.html
  8. https://commons.wikimedia.org/wiki/File:FN57SIGHTS03.jpg
  9. Aprea J. (2002). Hydrogen and hydrogen isotopes handling experience in heavy water production and related industries. International Journal of Hydrogen Energy. DOI: 10.1016/S0360-3199(01)00150-1 
  10. Arnoux R. (2011). Deuterium: a precious gift from the Big Bang. ITER Newsline. https://www.iter.org/newsline/167/631
  11. Arnoux R. (2012). The art of mixing fuels. ITER Newsline. https://www.iter.org/newsline/222/1164
  12. Arnoux R. (2016). Tritium: Changing lead into gold. ITER Mag 8. https://www.iter.org/mag/8/single#56
  13. Canadian Nuclear Safety Commission. (2010). Evaluation of Facilities Handling Tritium. www.nrc.gov/docs/ML1029/ML102990087.pdf 
  14. Egan C. (2012). A modified approach to muon-catalyzed fusion, employing helium-3 as fuel. Nuclear Instruments and Methods in Physics Research. DOI: 10.1016/j.nimb.2012.06.013 
  15. Huotari J. (2018). Twenty tons of uranium could be used to produce tritium for nuclear weapons. Oak Ridge Today. https://oakridgetoday.com/2018/09/14/twenty-tons-uranium-used-produce-tritium-nuclear-weapons/. Federal Order from https://www.govinfo.gov/content/pkg/FR-2018-09-11/pdf/2018-19686.pdf
  16. Koebrich, et al. (2018). 2018 Renewable Energy Data Book. U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy. https://www.energy.gov/sites/prod/files/2020/02/f72/2018%20Grid%20Integration%20Data%20Book.pdf
  17. Miller A. (2001). Heavy Water: A Manufacturers’ Guide for the Hydrogen Century. Canadian Nuclear Society Bulletin. https://cns-snc.ca/cns/cns_media/
  18. Nave R. (2016). Nuclear Fusion. HyperPhysics. http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.html#c2
  19. Prager S. (2011). How Seawater Can Power the World. Princeton Plasma Physics Laboratory. https://www.pppl.gov/news/publications
  20. Princeton Plasma Physics Laboratory. (2011). Fusion Power. PPPL Fact Sheet. https://www.pppl.gov/news/publications
  21. Ragheb M. (2019). Isotopic Separation and Enrichment. Nuclear, Plasma and Radiation Science. https://www.mragheb.com/
  22. Simko T., Gray M. (2014). Lunar Helium-3 Fuel for Nuclear Fusion: Technology, Economics, and Resources. World Future Review. DOI: 10.1177/1946756714536142 
  23. United States Nuclear Regulatory Commission. (2005). Tritium Production. https://www.nrc.gov/docs/ML0325/ML032521359.pdf
  24. Yang S., et al. (2018). Lithium Metal Extraction from Seawater. Future Energy. DOI: 10.1016/j.joule.2018.07.006