Nuclear weapons A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions , either fission or a combination of fission and fusion . Both reactions release vast quantities of energy from relatively small amounts of matter ; a modern thermonuclear weapon weighing little more than a thousand kilograms can produce an explosion comparable to the detonation of more than a million tons of conventional high explosive . Pre divergence . Nuclear weapons were first used in World War II on the Japanese cities of Hiroshima and Nagasaki in 1945 , effectively ending the war . These two explosions are said to have been seen as the start of the eventual end of the modern world that would come 132 years later , because it set a dangerous example for humanity that would come after this : that a war could be ended with nuclear weapons . The atomic bomb , a purely fission - based weapon , and the hydrogen bomb , a fission - fusion hybrid weapon , were both developed in the " Fallout " universe , with hydrogen bombs being considerably more dangerous because of the sheer size of their explosive yields . Post divergence . In the " Fallout world " , megaton - class thermonuclear weapons had largely been retired by the major nuclear powers in favor of much smaller - yield warheads by the time of the Great War . An average strategic warhead in 2077 ( with a few exceptions , such as the weapons which fell on Washington D . C . ) had a yield of about 200 - 750 kilotons , but with a massive increase in radioactive fallout in place of thermal shock , much like a salted bomb in our own world . However , despite the apparent reduction in raw explosive power , this arsenal was far more dangerous to the Earth ' s ecosystem , as it deposited far greater amounts of fallout in the atmosphere than had been assumed by pre - War models . China , the United States of America , the Soviet Union , the European Commonwealth ' s member states and other countries around the world possessed massive nuclear stockpiles , which they were not afraid to use against each other , or other nations in general . Limited nuclear exchanges occurred before the Great War as well . One Middle Eastern terrorist organization even managed to acquire at least one nuclear weapon , which was detonated in Tel Aviv , Israel in 2053 . A majority of the American , Chinese , and Soviet nuclear arsenals were used during the Great War , to devastating effect . The electromagnetic pulse resulting from every nuclear detonation rendered a large portion of humanity ' s electronics non - functional in an event later described as the Great Blackout . In - game . " Fallout " . In Fallout , the Glow is testament to the horror of nuclear war , a radioactive hellhole destroyed by a direct nuclear hit . In the same game , the Vault Dweller also discovers an unused nuke sitting in the Master ' s vault , to be used as last resort against an undefeatable enemy . " Fallout 2 " . A nuclear bomb also rests on the Enclave Oil Rig , and is , once again , used to obliterate the main enemy of the game ( detonated by an explosion of the on - board nuclear reactor ) . " Fallout 3 " . Nuclear weapons feature prominently in " Fallout 3 " , in the form of a C - 23 Megaton - Megaton ' s nuke , the Fat Man and its unique variant , the experimental MIRV , which are two tactical nuclear catapults , a bunker full of nuclear bombs , Vertibird s with nuclear carpet bombs , Liberty Prime ' s inexhaustible backpack arsenal of medium - sized bombs , various orbital weapons platforms such as Highwater - Trousers , and Bradley - Hercules - the Enclave - controlled satellite which destroys Liberty Prime in the " Broken Steel " add - on . Equally , near Fort Constantine the Lone Wanderer has the ability to launch a ballistic missile from a concrete silo via a computer terminal to an unmarked destination . However , the missile fails to launch . " " . The C - 23 Megaton returned in " " in the form of an undetonated atomic nuke called The One , which can be found north - west of the Devil ' s Throat if the player has the Wild Wasteland perk . The Fat Man also returned in " " ; it can be purchased from Knight Torres , a merchant in the Hidden Valley bunker . The also sell them . A unique version can also be purchased if the player has Gun Runners ' Arsenal add - on . In " Lonesome Road " many nuclear weapons are scattered throughout the Divide namely in an old missile silo . There are also some undetonated warheads scattered around in the divide that can be detonated using a Laser detonator . For more info see the page : " Lonesome Road " " " . A nuclear ICBM warhead appears first ( called Plutonius ) in Kansas City , worshiped by a ghoul cult . It is later used to gain entrance to Cheyenne Mountain installation , the Vault 0 . " " . A nuclear device also rests on the Secret Vault , as an emergency decontamination procedure ( a self - destruct system ) if the Vault started to become too dangerous . A special monorail located in the first complex of the laboratories section should be used to evacuate the vault dwellers quickly to a secret exit in the mountains . The Initiate activates it to obliterate all of its research and all of the experimental deathclaws , radbugs , super mutants , robots , and the heavily mutated Attis , destroying both the Secret Vault and the city of Los . " Van Buren " . The B . O . M . B . - 001 space station , the endgame location , was an orbital ballistic missile launch platform , that Victor Presper wanted to use to reshape the world as he envisioned it . Inconsistencies . The yield of the weapons in the games is never explicitly given . While it is stated that entire continents were scorched by nuclear weapons , their effects in the game are not even remotely similar to that description . Therefore , ten thousand or more nukes may have devastated the land . This would make sense , as each country would have at least a century ' s worth of nuclear weaponry in their stockpile . Also , during the 50 ' s in the real world , Nuclear Strategy favored brute - force precision strikes on military installations with ICBM while relying on heavily irradiating a country ' s population by dropping large amounts of small - yield nukes on highly populated urban areas from strategic bombers , as ballistic missiles were somewhat rare during this time . The war as it is portrayed in Fallout seems to follow this doctrine to a large extent as observable by many in - game reports and terminal entries . Also , many military facilities in the game where stated to be hit first during the nuclear exchange , such as the West - Tek facility , the Sentinel Site and many other strategic installations throughout the US . The way the weapons are portrayed in the games is inconsistent ; in the classic " Fallout " games , nuclear weapons are feared , respected , and exceedingly rare ( not to mention that arguably the most intelligent being in the " Fallout " world , the Master , is unwilling to unleash the power of the atom again ) . In " Fallout 3 " nuclear weapons are commonplace and devoid of their traits from previous games . You can destroy a small city with a nuclear bomb in the first few hours of the game , blow up cars in nuclear explosions and carry a personal tactical nuclear launcher . The term " nuke " is also , in the Fallout Universe , a generic name for anything that resembles a missile . When Liberty Prime is destroyed in " Fallout 3 " , there is no radioactive fallout , nor is there a scorched blast zone or mushroom cloud — the explosion is tiny in comparison to an real nuclear weapon ( though such weapons are sometimes refereed to as in universe as " Micro - Nukes " hinting that they were designed to have a much smaller blast radius ) . The same can be said about the mobile base crawler in the " Broken Steel " add - on when it is destroyed by an orbital strike — again , there was just an explosion , and no radioactive , flaming byproducts of a nuclear detonation ( although the Bradley - Hercules system may have only used conventional warheads ) . This may indicate the missiles aboard B . O . M . B . - 001 or other orbital platforms were not actually primed with warheads , but were missiles waiting to be armed . Another inconsistency with " Fallout 3 ' s " nuclear missile theory is the shape of the actual weapons themselves . Some , like the one within Megaton are 1940s " Fat Man " atomic bombs : powerful , but were quickly surpassed by even stronger thermonuclear ( or " hydrogen " ) weapons , which were not barrel - shaped but were more streamlined in appearance . There are the more ' ballistic ' missiles — the converted " space shuttles " — that are launched from concrete silos ( like the one outside Fort Constantine ) or submarines ( like the Chinese Yangtze ) . Most missiles that can still be found are either broken or still waiting for launch , as some officers refused to fire their warheads including an entire arsenal of them in The Divide . Oddly enough , while most of the strategic arsenal of the US has been launched , most orbital installations appear to have been forgotten about , or only partially launched their payload . It is unknown whether this is a design oversight , or if the weapons were indeed not properly armed . Appearances . Nuclear weapons appear in all " Fallout " games .