History Main / GoingCritical

** In the episode "Homer Defined," the reactor begins to go critical, and Homer (of course) does ''not'' remember his training for what to do during this very event. He picks a button at random with "Eeny Meeny Miney Mo"...and luckily for him, that's the button to initiate the SCRAM procedure. Everyone makes him out to be a hero, but he feels guilty because it was [[AccidentalHero nothing more than luck]].

*** Earlier in that episode, Homer's computer asks "Vent radioactive gas?", when Homer responds no the computer insists "Venting prevents explosion."

->''"Last night {{UsefulNotes/Chernobyl}} nuclear power plant [[MetaphoricallyTrue fulfilled]] the Five Year Plan for heat energy generation in four microseconds."''

* A major event midway through ''VisualNovel/AnalogueAHateStory'', when the ''Mugunghwa'''s main reactor - which has gone some ''six hundred years'' in low-power mode without proper maintenance - starts failing. When it starts, you're given an ExactTimeToFailure of twenty minutes, and it's made pretty clear that this is not enough time to get out of the blast radius, despite the PlayerCharacter being in pretty much the best possible position to be doing so.

** In ''VideoGame/{{Fallout 2}}'', the Chosen One destroys the Enclave and their Oil Rig base by sabotaging the nuclear reactor powering it, leading to a massive mushroom cloud in the ending cinematic.

* ''VideoGame/{{Portal 2}}'': The Aperture Science Enrichment Center's nuclear reactor spends, all together, well over half the game either going critical or warning you that it's about to go critical.

* In ''VideoGame/SyphonFilterLogansShadow'', one level has you aboard a recently sunk nuclear powered navy ship with the nuclear reactor about to "go critical" forcing you to hurry and shut it down by removing the fuel rods instead of inserting control rods as would be done in reality.

* In both RealLife and ''Series/{{Chernobyl}},'' the insertion of the reactor's graphite-tipped control rods into an already-critical reactor caused it to go ''super''critical for a breif instant (graphite is a neutron ''accelerator''), melting the coolant system and causing the coolant (water) to spill onto the hell-hot fuel rods, resulting in a blast of superheated steam that ripped the roof off of the reactor vessel and resulted in a meltdown. Nuclear scientist Legasov is, however, concerned that if the mixture of melting fuel, powdered boron (meant to poison[[labelnote:*]]yes, that's the technical term[[/labelnote]] the reaction), and sand (meant to smother the flames) hits the coolant reservoir, the resultant explosion will be about 2-4 megatons (read: million tons of TNT), which is more in line with this trope. A good-sized glob of this "lava" (known as corium) would cause another steam explosion that would sure as hell make things worse, but it wouldn't go up like a nuke [[DiabolusExMachina unless all of it was dropped into the reservoir at once (and then in a wide pattern that would maximize flash-heating).]] Sub-trope of ScaryScienceWords.

->''"Last night {{UsefulNotes/Chernobyl}} nuclear power plant fulfilled the Five Year Plan for heat energy generation in four microseconds."''

* Third-generation Arm Slaves in ''LightNovel/FullMetalPanic'' are said to use palladium reactors (older ones run on diesel/gas turbines). Judging from the Helmajistan ambush, these things pack quite a punch. One might even mistake the self-destructing Codarl at the end of the first season as a meltdown but he explicitly states that he packed a few hundred kilos of high explosive to make sure he can pull off a TakingYouWithMe. On the other hand, the onboard AI warned him that if he starts the sequence, there's no cancelling it. So he might have gone for a straight overload spiced with some extra HE for a bigger boom.

* ''LightNovel/RebuildWorld'': LostTechnology knives, as well as Shiori’s katana which is based on similar designs, can have the safety shot off which makes it into a LaserBlade for only a few seconds, but said blade has AbsurdCuttingPower. Doing this makes the rest of the knife disintegrate (or with Shiori’s katana, just the blade needs replaced).

* The ''{{Franchise/Alien}}'' franchise has done this twice - first with the reactor of the ''Nostromo'' in ''{{Film/Alien}}'', and then with the reactor of the atmosphere processor in ''{{Film/Aliens}}''. In the first example, this is because Ripley turns on the SelfDestructMechanism on the ship to kill the alien and is too late to turn it back off. In the second, it was the result of weapons being fired inside the plant that damaged the cooling system and set off a slow chain reaction.

In fiction, the word "reactor" seems to mean [[SmallReferencePools exclusively nuclear reactions]], despite the word being common enough in chemistry since "reactor" simply means where a reaction happens. Another contrast between fiction and reality occurs with the term "critical". Fiction uses the word to say "it's going to explode!", whereas real nuclear physics use it to say "the reaction sustains itself", so a reactor is critical if it's ''on''. Relatedly, "supercritical" simply means the reaction is increasing in power, and a surge of power causes "prompt critical", which means the reaction is critical solely from the "prompt" neutrons created by fission events, which means an explosion is imminent.[[note]]Since a neutron in flight cannot be controlled by processes working at human time scales, reactors are designed to be critical with the "delayed" neutrons released by subsequent isotope decay. This may have happened only once, in the [[http://en.wikipedia.org/wiki/Sl-1 SL-1 reactor accident]].[[/note]] (Designed bombs, on the other hand, go "[[BreadEggsBreadedEggs prompt supercritical]]".) Also incorrect is "meltdown", meaning an explosion suspiciously similar to that of an atom bomb, or at least large enough to [[MadeOfExplodium blow the vehicle/facility in question to pieces]]. In real nuclear physics, meltdowns are just that - the fissile core ''melts'' into slag, hot enough to flash coolant into steam (wherein you get the associated bang) and possibly melt through the reactor vessel.

** In the Original Series episode "[[Recap/StarTrekS2E6TheDoomsdayMachine The Doomsday Machine]]", , Scotty jury-rigs the badly damaged U.S.S. ''Constellation'' so that its impulse drive can function. He says repeatedly that keeping it from exploding is taking all of his effort.

*** In "The Doomsday Machine" (episode of ''Series/StarTrekTheOriginalSeries''), Scotty jury-rigs the badly damaged U.S.S. ''Constellation'' so that its impulse drive can function. He says repeatedly that keeping it from exploding is taking all of his effort.

** However, there are some instances of explosions that are just plain silly. ''Anime/AfterWarGundamX'' shows a number of nuclear power plants abandoned AfterTheEnd that were not only apparently left running, but seemingly the slightest damage(or deliberate removal of certain components) would cause them to explode.

* In ''VideoGame/HalfLife2'', A dark matter reactor in a Doom Fortress is enough to fling cars into the air and knock a train off its tracks at least a mile away.
** {{Justified|Trope}}: The Combine forces were very specifically ''trying'' to get the dark matter reactor to explode.

*** Earlier in that episode, Homer's computer asks "Vent radioactive gas?", when Homer responds no the computer insists "Venting prevents explosion." Which becomes a FunnyAneurysmMoment when in Fukushima reactor technicians did ''exactly that''. And it still [[ShaggyDogStory didn't prevent the explosion]].

All reactors currently in use are designed with safe failure modes in mind; the worst you really get from a land-based reactor failing is to get a reactor container full of "corium", which is essentially lava formed from whatever was in the reactor core at the time and is as radioactive as you'd expect from a reactor's worth of nuclear fuel. The famous disasters are caused by the corium melting through safety features. On a sea vessel, the contamination would be [[UpToEleven horrific]]; the reactor mass would come into direct contact with the seawater, and shatter or even be entirely vaporized to small particles (fallout) in the massive subsequent vapour flash explosion. Radiation ''will'' be an issue inside the facility, and widespread fallout of the kind associated with nuclear war only occur when the containment systems have been ruptured. Long story short, a meltdown is ''extremely'' bad news, but orders of magnitude less bad than even small (i.e. tactical) nuclear weapons.

In fiction, the word "reactor" seems to mean [[SmallReferencePools exclusively nuclear reactions]], despite the word being common enough in chemistry since "reactor" simply means where a reaction happens. Another contrast between fiction and reality occurs with the term "critical". Fiction uses the word to say "it's going to explode!", whereas real nuclear physics use it to say "the reaction sustains itself", so a reactor is critical if it's ''on''. Relatedly, "supercritical" simply means the reaction is increasing in power, and a surge of power causes "prompt critical", which means the reaction is critical solely from the "prompt" neutrons created by fission events, which means an explosion is imminent.[[note]]Since a neutron in flight cannot be controlled by processes working at human time scales, reactors are designed to be critical with the "delayed" neutrons released by subsequent isotope decay. This may have happened only once, in the [[http://en.wikipedia.org/wiki/Sl-1 SL-1 reactor accident]].[[/note]] (Designed bombs, on the other hand, go "[[UpToEleven prompt supercritical]]".) Also incorrect is "meltdown", meaning an explosion suspiciously similar to that of an atom bomb, or at least large enough to [[MadeOfExplodium blow the vehicle/facility in question to pieces]]. In real nuclear physics, meltdowns are just that - the fissile core ''melts'' into slag, hot enough to flash coolant into steam (wherein you get the associated bang) and possibly melt through the reactor vessel.

* Ironically averted in ''VideoGame/MetroidFusion''. For a series with so many [[EarthShatteringKaboom catastrophic countdowns]], the main reactor-related emergencies in Fusion aren't explosive. In the first instance, the cooling systems in the high-temperature habitat are deliberately shut down, risking a ''boiler'' explosion; in the second, vines invade the reactor and SCRAM it. The later [[EarthShatteringKaboom destruction of the station]] is caused deliberately by [[ColonyDrop running it into the nearby planet.]]

* In an issue of Franchise/TheDCU comic book miniseries ''ComicBook/IdentityCrisis'', [[spoiler:ComicBook/{{Firestorm}}]] is skewered by a sword, and is told to fly off for the safety of others as "everybody knows what happens if you puncture a reactor". If they meant that a containment breach causes a potentially deadly radiation leak, this would've been forgivable.

* Averted in ''FanFic/HeroesOfTheDeskRepercussions''--a US supercarrier is sunk in shallow water but [[RealityEnsues the Navy gets the situation under control]]. Of course, since this trope exists, some people panic anyway even though nothing bad happens.

* Unsurprisingly, this is a recurring concept in ''Franchise/{{Fallout}}'':

** This is even part of the backstory, it's been mentioned in the series timeline that in 1965, about 12 years before the Great War, a nuclear reactor in New York almost went critical due to the enormous power demands of that summer, forcing the U.S to start rationing electricity.

* In both RealLife and ''Series/{{Chernobyl}},'' the insertion of the reactor's graphite-tipped control rods into an already-critical reactor caused it to go ''super''critical for a breif instant (graphite is a neutron ''accelerator''), melting the coolant system and causing the coolant (water) to spill onto the hell-hot fuel rods, resulting in a blast of superheated steam that ripped the roof off of the reactor vessel and resulted in a meltdown. Nuclear scientist Legasov is, however, concerned that if the mixture of melting fuel, powdered boron (meant to poison[[labelnote:*]]yes, that's the technical term[[/labelnote]] the reaction), and sand (meant to smother the flames) hits the coolant reservoir, the resultant explosion will be about 2-4 megatons (read: million tons of TNT), which is more in line with this trope. A good-sized glob of this "lava" (known as corium) would cause another steam explosion that would sure as hell make things worse, but it wouldn't go up like a nuke [[DiabolusExMachina unless all of it was dropped into the reservoir at once (and then in a wide pattern that would maximize flash-heating).]]

* {{Discussed}} in ''Film/K19TheWidowmaker.'' The reactor's cooling system bursts and the crew attempts to SCRAM the reactor, but without the coolant, the reaction will still continue to build to runaway proportions. Eventually, it'll hit 1,000°, and then "nobody knows." The film's page states that, if the core had gone into meltdown and hit the ice-cold seawater, "you'd be hard pressed to find any part of the sub bigger than your hand." The major concern is that [[ANuclearError this will set off the ship's nuclear missiles (which is actually impossible to do by accident, nukes being surprisingly finnicky weapons).]]

* In ''VideoGame/{{Fallout 2}}'', the Enclave Oil Rig's reactor goes up in a big nuclear explosion.

* {{Discussed}} in ''Film/K19TheWidowmaker.'' The reactor's cooling system bursts and the crew attempts to SCRAM the reactor, but without the coolant, the reaction will still continue to build to runaway proportions. Eventually, it'll hit 1,000°, and then "nobody knows." The film's page states that, if the core had gone into meltdown and hit the ice-cold seawater, "you'd be hard pressed to find any part of the sub bigger than your hand." The major concern is that this will set off the ship's nuclear missiles (which is actually impossible to do by accident, nukes being surprisingly finnicky weapons).

* In the Film/JamesBond movie ''Film/TheWorldIsNotEnough'', TheDragon Renard attempts to turn the reactor in a nuclear sub critical by inserting a rod of weapons grade plutonium. In the bare reactor. With nothing more than a shirt protecting him from hard radiation. Granted, he wasn't expecting to survive the act, but Bond is there with him. This might be slightly forgivable given that the intent was to contaminate the whole area, not necessarily blow it to hell. Of course, nobody except Dr. Jones actually understands how inserting the weapons grade plutonium into the reactor would cause an 'instant, catastrophic meltdown'. As a matter of fact, fuel rods made of weapons-grade fissiles just react ''longer'' due to the removal of anything that would choke up the reaction.

* In the Film/JamesBond movie ''Film/TheWorldIsNotEnough'', TheDragon Renard attempts to turn the reactor in a nuclear sub critical by inserting a rod of weapons grade plutonium. In the bare reactor. With nothing more than a shirt protecting him from hard radiation. Granted, he wasn't expecting to survive the act, but Bond is there with him. This might be slightly forgivable given that the intent was to contaminate the whole area, not necessarily blow it to hell. Of course, nobody except Dr. Jones actually understands how inserting the weapons grade plutonium into the reactor would cause an 'instant, catastrophic meltdown'.