Institute reactor 6

The interior of the Institute reactor, a tokamak fusion reactor

Nuclear fusion is a reaction where two different atomic nuclei are combined to form one or more different nuclei and subatomic particles. The reaction can potentially release energy and be a more powerful and cleaner source of energy than nuclear fission.


Although the idea of harnessing power from fusion energy has been proposed since the 1940s, the only "practical" use for these weapons has been the development of thermonuclear weapons, with yields several times greater than fission-based weapons. It was not until the 21st century and the energy crisis that the United States finally developed a practical way to harness nuclear fusion for energy generation. The first fusion cell was revealed in the Summer of 2066, as an offshoot of the U.S. power armor project. The technology developed rapidly, becoming the cornerstone of many civilian and military technologies. Although the process of incorporating nuclear fusion into the general U.S. infrastructure began in 2066, nuclear fusion proved to be difficult to scale to industrial-level power generation and by 2077 only a few sections of the United States relied on fusion power for baseload generation, according to the Fallout Bible.[1]

Nuclear fusion relies on the capture of radioactive energy from microfusion reactions,[2] rather than generating power by using heat energy to drive turbines, as with nuclear fission.[3] The hot fusion reaction thus created is distinct from sustainable nuclear reactions achieved through electrochemical processes at or near room temperatures (so-called cold fusion), which are considered to be impossible to achieve.[4] This impossibility did not stop Vault-Tec from referring to the fusion generator at the core of the Garden of Eden Creation Kit as a cold fusion generator.[5]


The discovery of nuclear fusion has revolutionized life and industry in the United States, slowly supplanting nuclear fission as the premiere power source. Its uses were many and varied, including:

  • Power armor: The TX-28 micro fusion pack developed by West Tek was capable of producing the power necessary to make power armor a practical weapon. Using fusion cores as reaction starters and sources of fuel, the fusion-powered power armor revolutionized modern warfare.[6]
  • Laser weapons: The introduction of the micro fusion cell, a medium sized energy production unit and a self-contained fusion plant allowed for the creation of directed energy weapons. The MFC became the de facto industry standard and became a common choice for large energy weapons of all stripes, such as laser and plasma rifles.[2][7] MFCs could also be turned into improvised satchel charges by removing safety catches.[8] Further innovation on the MFC came in the form of the recharger rifle, improved upon by the recharger pistol, utilizing a special microfusion breeding technology.
  • Nuclear propulsion: After the introduction of fission-powered cars, fusion batteries and engines started to dominate the market. Unfortunately, they also suffered from the same design flaws that caused aging car engines to become unstable - explosively so.[9][10]
  • Nuclear weapons: One of the oldest forms of practical nuclear fusion. One of the peculiarities of United States technological development is the fusion pulse charge, which can be used to turn working fusion reactors into thermonuclear weapons.[11]
  • Portable power generation: The dominant form of power generation were portable fusion generators,[12] such as the ones produced by GDA Fusion for household power generation.[13] This kind of technology was also developed after the Great War by certain wasteland organizations, like Rivet City.[14]
    • Microfusion power units are also sometimes referred to as batteries, especially when installed in appliances. These have the same effect and can provide a lasting supply of energy and keep the device independent of the existing energy grid.[15]
  • Robotics: Fusion piles were used to power certain advanced robot types, such as the Robobrain and Assaultron combat robots.[16][17]
  • Fusion core: A standardized high-grade, long-term nuclear battery used in a variety of military and civilian applications.[18][19]
  • Large scale energy generation: One of the major potential uses of fusion energy, pre-War United States experienced some limited success with scaling the technology up to fusion generators, capable of powering entire buildings and providing backup power for Vaults.[20] Nuka-Cola Corporation paired multiple fusion reactors to meet the energy demands of Nuka-World, the corporation's flagship amusement park.[21] However, efforts to further expand the power generation have proven problematic. Mass Fusion was developing an experimental reactor before the Great War that could provide power at a large enough scale to replace conventional fission power plants. However, their work was never completed.[22] The key obstacle was the energy required to trigger the reaction and make it self-sustaining. Mass Fusion's chief achievement was the creation of the beryllium agitator, which would allow the fusion reaction to be jumpstarted much more easily.[23][24] It is possible to start the reactions conventionally, although doing so requires prohibitively large amounts of energy: Robert House would require the power output of the restored Hoover Dam to restart Lucky 38's reactor.[25] Another issue, especially with systems used in non-standard role like the Prydwen, is cooling. A sustained reaction requires a constant supply of coolant, which can be problematic to obtain.[26]
    • The military used fusion power to a great extent. The Appalachian Automated Launch System in particular reduced on a combination of onsite fusion reactors and megacells to provide power to its nuclear silos, with the most common types used being military-grade Class-VIII and Class-IV fusion reactors connected in a closed circuit, capable of serving as the silos' primary power source indefinitely.[27][28] Vault-Tec profited from its role as a strategic defense contractor, obtaining compact fusion power systems from the military for use in its facilities.[29]

See alsoEdit


  1. Fallout Bible 0
    2065-2067 Power Armor research grows and several prototypes are developed, many of which prove to be unworkable in the field. These prototypes pave the way for future advances in military, construction, and fusion technology.
    2066 Summer Adding further insult to the Chinese-American relations, the first crude fusion cell is unveiled, one of the results of the Power Armor project. Devices designed for the fusion cell begin to be manufactured. Incorporating fusion power into the general US infrastructure begins, but the process is too slow to supply power to the regions that need it. Nearly eleven years later, few sections of the United States were supplied with fusion power."
  2. 2.0 2.1 Fallout and Fallout 2 item description: "{3900}{}{Micro Fusion Cell}"
    "{3901}{}{A medium sized energy production unit. Self-contained fusion plant.}"
    (PRO ITEM.MSG (Fallout), PRO ITEM.MSG (Fallout 2))
  3. Cambridge Polymer Labs terminal entries; Ericka's terminal, Thermal dissipation
  4. The Institute terminal entries; terminal, Cold Fusion
  5. See Garden of Eden Creation Kit for references.
  6. See power armor for details.
  7. Energy weapons throughout the Fallout series use MFC as ammunition.
  8. The Courier: "Remove the safety catches on those Microfusion Cells and you could turn them into satchel charges."
    ED-E: "[SUCCEEDED] <Happy beeping>"
    (ED-E's dialogue) Note: With the addition of Lonesome Road ED-E can turn microfusion cells into satchel charges if the player character has an Explosives skill of 65.
  9. Fallout 2 Official Strategies & Secrets p.93-94: "Chrysalis Motors Highwayman
    One of the most useful items that you'll find is this shining example of American iron. The Chrysalis Motors Highwayman was once renowned for its high performance and durability. "Nothing can stop a Highwayman" was a phrase familiar to most drivers. The motto still holds true today. If you repair the car with a part that you'll find in Gecko, you can fuel it with standard energy cells and use it to move quickly across the world map, well equipped to outrun most enemies that you'll find.
    Towns in the post-apocalyptic world don't allow motor vehicles on their streets, citing something about aged fuel cells exploding. However, parking your Highwayman on the outskirts of town gives you access to a quick getaway as well as a secure storage spot for your goodies within the car's spacious trunk."
  10. All car explosions use the EXPL - FusionCarBatteryExplosion [00025C20] record.
  11. Fusion pulse charge
  12. Project Purity Personal Journal: Entry 2
  13. GDA Fusion
  14. The Lone Wanderer: "What is this lab? What are you doing here?"
    Madison Li: "This is the Rivet City Science lab. It's taken many long years to put together, but we've done well for ourselves. Our work on portable fusion power and hydroponics are coming along quite nicely, if not quite according to schedule."
    (Madison Li's dialogue)
  15. Harpers Ferry terminal entries; Med-Tek Sympto-Matic terminal, Technical Notes 031177MTS
  16. RobCo sales & service center terminal entries; Chief Engineer's terminal, Maintenance Issue 09008777-AC
  17. RobCo Battlezone terminal entries; Control Room terminal, Inbox: 101177
  18. The Sole Survivor: "I'll help if I can."
    Preston Garvey: "What you'll need is an old pre-war F.C., a standardized Fusion Core. Your high-grade, long-term nuclear battery. Used by the military and some companies, way back when. And we know right where to find one..."
    Sturges: "But we can't get to the damn thing. It's down in the basement, locked behind a security gate. Look... I fix stuff. I tinker. Bypassing security ain't exactly my forte. You could give it a shot."
    (Preston Garvey's dialogue|Preston Garvey and Sturges' dialogue)
  19. Fusion core
  20. Versicorps Fusion Power
  21. Nuka-World loading screen hints: "Nuka-World's Power Plant contained multiple fusion reactors which were necessary to satisfy the needs of Nuka-World's parks and attractions."
  22. Danse: "Had they gotten it operational, Mass Fusion's experimental reactor would have made places like this obsolete."
    (Danse's dialogue) This line is spoken when at the Natick power station.
  23. Spoils of War quest stage description: "In order to restart Liberty Prime's reactor core, I need to recover the "Beryllium Agitator" from the ruins of Mass Fusion. I should board a vertibird and head over there as soon as possible."
  24. The Sole Survivor: "How can a "Beryllium Agitator" start up his reactor?"
    Ingram: "If Prime's reactor is a campfire, the Beryllium Agitator is like a match. Strike it, throw it on the logs, and the whole thing ignites. Fusion reactors need a massive power surge in order to get the reaction started. Once it starts, it's self-sustaining. I'm sure I could get one of my scribes to bore you to death with the details, but you get the gist."
    (Ingram's dialogue)
  25. Robert House: "Between the Strip and HELIOS One lies the El Dorado electrical substation. Humble as it appears, the substation has immense strategic value, for it's there that you'll jumpstart the Lucky 38's dormant reactor. Gain access to the substation's control room and install this override module. Just so you know, there are NCR troops guarding the station."
    (Robert House's dialogue)
  26. The Sole Survivor: "Approve? Are you kidding me? That's an understatement."
    Ingram: "Now, I'm not so sure using the Minutemen to do the deed was the best idea... But you got the job done, and in my book... that's what really counts. You almost single-handedly finished everything that the Brotherhood came here to do. Even to a curmudgeon like me, that's pretty impressive. Anyway, I'm not here to talk your ear off. Maxson's informed me that you're continuing your tour aboard the Prydwen so I was hoping you could assist me with a long-term problem. Keeping the Prydwen hovering like this is putting a tremendous strain on the ship's propulsion systems. I can stay ahead of the repairs, and we have plenty of fuel to keep the fusion reaction sustained, but we're short on Reactor Coolant."
    (Ingram's dialogue)
  27. Missile silo terminal entries; Reactor control terminal, Power System Overview
  28. Missile silo terminal entries; Reactor control terminal, Power System Repair Instruction
  29. Vault-Tec University terminal entries; Vault-Tec Mission Statement Terminal, Our Facility
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