A lot of mistakes, errors and bad science that's often pops up in sci-fi story regarding nuclear technology:
1.Nuclear=Explosion: This one is almost always pops up when general public thinks about the word "nuclear". Basically, if it contains that word , it'll go boom if something, anything, happens to it. It's going to "go critical" and blow up like atomic bomb. It doesn't matter if it's designed not to do that, it doesn't matter if it's not fissile enough to be used for an atomic bomb, it doesn't matter if it hasn't got enough material for critical mass, IT WILL GO BOOM. In real life, a nuclear weapon requires an extremely precise conditions to achieve full detonation (mainly a sphere of conventional explosives being set off in unison around the nuclear mass, compressing it to supercriticality and initiating a nuclear reaction). The precise engineering of a nuclear weapon makes the best Swiss watch look like a flint knife in comparison. In fiction, it's often like a sphere filled with a truckoad of mega-nitroglycerin
2.Do Not Tamper With Nuke, You Could Set It Off: As quoted in Armageddon when the main character is about to whack the nuclear bomb with a wrench. In real-life, shooting, or even blowing up a real-life nuclear weapon with conventional explosives is likely to disable the warhead, not set it off. In fact, here's a film produced by the US Air Force back in 1960 (https://archive.org/details/StaySafe1960) showing nuclear weapons being purposely dropped out of planes, set on fire, and otherwise subjected to movie-of-the-week hijinks to demonstrate that rough treatment of nuclear weapons does not result in said weapons detonating. Nuclear weapons is designed to go off ONLY when you want it. After all, you don't want to lose a huge chunk of your country because someone accidentally dropping a nuclear warhead during bomber rearming operations on an airbase
3. Only The Hero Can Stop The Meltdown: If a reactor does melt down or is going to melt down, the hero usually has to manually initiate a SCRAM, an emergency shutdown, sometimes going to elaborate lengths to set the SCRAM up or even having to manually insert the control rods into the reactor one at a time for the sake of drama. This is as opposed to real life, where it's typically an automatic safety feature which engages if the reactor shifts outside a certain set of safe operating parameters and where a manual reactor SCRAM is as simple as turning a switch. A switch that usually exists in multiple redundant locations both near and far away from the reactor room, so that you can always reach at least one during an emergency. What's more, even the failsafes have "dead-man" failsafes. Usually, the SCRAM mechanism has to actively prevent the shutdown from happening — for instance, by constantly pushing against a spring, or holding up control rods with an electromagnet. If power to the safety systems is interrupted even for a moment, the mechanism stops resisting and the reactor shuts down.
4. Nuclear Reactor Goes Mushroom Cloud: Fictional nuclear reactors will melt down or go up in gigantic nuclear explosions at the slightest thing going wrong. A nuclear reactor simply cannot cause a full-scale nuclear explosion: fuel assemblies are arranged into long, thin columns separated by cladding; the large surface area causes a significant percentage of the available fission neutrons to dissipate into the moderator rather than causing further fission events, preventing a critical mass from forming. A core for a nuclear weapon needs a near-spherical shape for any kind of runaway chain reaction, and depending on size and material may also need a neutron reflector. Anyway, even in the extremely unrealistic scenario when nuclear fuel made of pure metallic weapons-grade uranium or plutonium melts down and forms a perfect sphere of critical mass, it still needs one more condition to explode: for this mass to be squeezed into the critical radius, achieved in bombs only under tremendous pressure created by chemical explosives and in a very short (on the order of milliseconds) time window. Otherwise this sphere will simply heat up and boil. As a matter of fact, most of the nuclear fuel in the world is NOT metallic. It is based on the metal oxides precisely to prevent it from easily melting or burning. And no matter how hard one tries, it is simply impossible to reach critical radius with oxides. In fiction, a reactor melting down is always a Chernobyl-level catastrophe regardless of design. Most of the consequences of the Chernobyl meltdown were a direct result of the plant being built without a containment building, a structure that surrounds the reactor itself and is intended to reduce any consequences of a leakage or meltdown. In addition at Chernobyl, several safety systems were deliberately turned off for a scheduled experiment. These work rather well: in Three Mile Island, the containment building duly contained the steam and other bad effects of the meltdown. No pyrotechnics; in fact, the radiation released from Three Mile Island was less than the radiation coming from your computer monitor. Even in the SL-1 incident in 1961 (the only fatal reactor accident in the United States and another example of terrible control rod design), which lacked a designed containment building, the regular old building contained most of the radioactivity. Even with that, it proved that the core and water coolant vaporizing would prevent the core from melting down. Chernobyl's core of uranium fuel was surrounded by graphite, making the reactor a giant block of charcoal waiting to ignite into carbon-14 => radioactive CO2 goodness. British nuclear power plants also use graphite as the moderator, except for Sizewell B, but they use carbon dioxide gas as coolant where Soviet reactors used water. It was the combination of graphite moderator and water coolant that made Chernobyl a death trap. In addition, the conditions for Chernobyl accident were caused by 'scientists' performing experiments during the night shift, when the inexperienced crew, only capable of following directions from a manual, were not aware of, or able to properly react to, the conditions before it was too late to save the reactor. What happened was the operators initiating the test after they screwed up and hastily corrected themselves. The screw-up was safe and unrelated to the experiment, and had they shut down the reactor normally as intended (and written in the manual) nothing would happen. They, however, pressed on (allegedly to have something to report as an achievement at the upcoming May Day celebration - and even then, it was after two of the more senior operators complained that it wasn't safe to proceed, though when they were threatened with losing their cushy jobs they knuckled under). Unfortunately, their previous actions has left the reactor in the unstable and unstudied state, and in the process of the test they removed the last control rods, causing the reactor to heat up. When it got WAY too hot, they tried to fix it by fully inserting all the control rods. The reactor promptly blew up, though it was not actually a nuclear blast, it just threw radioactive junk everywhere.
5. SCRAM=All Is Safe: A reactor "shutdown" simply slows down fission events to a subcritical level; the radioactive decay of fission products inside the reactor still produces a significant amount of heat — enough in the case of Three Mile Island (which was SCRAMmed very early in the timeline of the casualty) to damage the core and release radioactive material into the environment. The reactors in Fukushima were shut down upon the initial earthquake and still produced enough decay heat days later to cause full meltdown and hydrogen explosions. Even worse, at Chernobyl, the SCRAM signal aggravated the casualty (inside baseball: the control rod followers were made of neutron-transparent graphite, and replaced neutron-absorbing water in the control rod channels, causing a temporary spike in fission events before the even-more-neutron-absorbing boron control rod body was in place, driving the reactor over the edge into prompt criticality).
6. What's Void Coefficient?: The Void Coefficient is probably deemed too scientific for the general public, so it's conveniently assumed that all reactors will suffer the same from thermal runaway. In real life, most reactors have a negative Void Coefficient, which means that they will reduce their thermal output when gas (steam) bubbles form in the coolant. In contrast, a positive Void Coefficient will increase heat output when gas bubbles form in the coolant. A well known reactor model with a dangerously high positive Void Coefficient is the High power reactor (Реактор Большой Мощности Канальный). Originally, this model's Void Coefficient was 4.7 beta, but it has been lowered to 0.7 beta after one of the reactors of this model gained negative publicity due to the Chernobyl accident.
7. Stealing Fuel Rod To Build A Nuclear Bomb: A common plot of stealing nuclear reactor fuel rods to build nuclear weapons. in real life, reactor fuel and weapons material are simply not interchangeable. Nuclear weapons require specific isotopes — uranium-235 or plutonium-239 — of very high purity (referred to as "weapons grade"), and reactor fuel doesn't even come close. A practical uranium design requires its uranium to be around 80% or more uranium-235, while the fuel in a civilian nuclear reactor consists of just 3-5% uranium-235, and in a submarine reactor up to 20%. And while you can relatively easily (assuming you have a fully equipped radiochemical plant) extract plutonium from spent fuel (and some fuels contain plutonium already mixed in), it will be a mixture of isotopes with only a small fraction being plutonium-239. Any significant admixture of other isotopes will make the plutonium useless or worse for weapons use, and isotope separation is a long, slow, infrastructure-dependent, and energy-intensive operation beyond the reach of most governments, never mind terrorist organisations.
8. Going Critical: And on the subject of Criticality, any time some thing goes wrong in a nuclear facility, terrified screams of "It's Going Critical" will fill the air, or the villain's plan will be to make the reactor go Critical. "Critical" means that the reaction is self sustaining and that the reaction is proceeding at a constant level — in other words, a critical reactor is one that is operating at a steady constant power level. One more time, "Critical" reaction is the normal operating condition of a nuclear reactor. Super-Critical, while not used despite sounding definitely bad, simply means that the reaction is steadily gaining power, or simply, someone getting powered by the reactor turned on a light and so the reactor went temporarily super-critical to increase its energy output for the new drain. Finally, there IS a condition that would (almost) elicit the reactions of a Hollywood type critical reactor. It's called Prompt-Critical, and if a reactor has had this happen, there'd be no running around trying to prevent it or saying it happened; by the time any readings showed this happening, it would already be too late, and either the automatic safety systems would have kicked in and shut down the reactor, or the reactor pile would be an actual pile of slag. Due to the abovementioned misconception of "critical mass", it's Hollywood-assumed that any minor wrong could send a nuclear reaction to prompt-critical. This is not practically the case, because, as we should more accurately speak of "critical density", most nuclear reactors are designed to stay below that at any time, including loss-of-coolant situations. Most commercial reactors are cooled and moderated by water; a loss of coolant would risk fuel melting, but the reactor would go subcritical from the loss of coolant. Even if they are moderated by graphite, like Chernobyl or Windscale reactors, the meltdown is the worst thing that ever can happen with them. The most of the damage in Chernobyl and Fukushima was from the destruction of the reactor buildings, that lead to the spread of the "hot" junk around. This comes from the Hollywood idea of reactors as bombs-in-waiting. When a nuclear bomb "goes critical", it's actually going Prompt-Critical which is why it explodes, thus when a reactor goes critical, it's about to go kaboom.
9. Reactor Core =/= Cooling Tower: A lot of movies assumes the reactor core is inside the cooling tower. Because most people associate "nuclear power plants" with those giant hyperboloid structures as seen on cartoons, it's an easy mistake to assume that they are the plant and contain the reactor. In reality, the reactor is typically located in a separate block-shaped building (which ideally serves as a containment), and the towers are just the enormous radiators that contain and manage the cooling water. There are other types of power plants (such as coal plants) that have cooling towers which look just like the ones commonly associated with nuclear plants, whereas there are nuclear plants that don't have cooling towers. Notably, both the wrecked Chernobyl and Fukushima plants don't have them (Chernobyl has an unfinished cooling tower intended for unfinished additional reactors): Chernobyl used cooling ponds instead of towers, and Fukushima was cooled by the whole Pacific Ocean. Since the cooling towers are open on the top, placing the reactor inside would expose it to the open air, which would obviously be a bad idea.
10. Portable Nuclear Grenade: On the subject of critical mass, while both low-yield nukes and still-bulky "suitcase" nukes do exist in real life, critical mass means that there is an absolute lower limit on the size, weight, and yield of fission-based nuclear weapons. There are some exotic transuranic elements such as curium and californium with a much smaller mass, and in theory you could make an nuclear grenade out of them. In practice, they (and just about anything besides uranium and plutonium) would suffer from a whole rash of pre-ignition and stability issues, so you wouldn't be able to get them to explode outside of ludicrously rare lab conditions. (The reason that uranium and plutonium are useful in nuclear weapons is that they're not that radioactive. The plutonium isotope used in weapons has a half-life of 24,000 years; U-235 has a half-life of 700 million years. The really intense stuff is too unstable to actually build a weapon around.) "Critical mass" is a highly misunderstood term. Whether a sample of fissile material will produce an uncontrolled chain reaction is dependent on (roughly) the ratio of mass to surface area. If the ratio is too low (too much surface area) neutrons escape without causing further fission. If it's above the critical ratio, then of the three neutrons produced by each fission, on average >1 will cause another fission (meaning that the rate of reactions will grow). The oft quoted "critical mass" is the critical mass where a sphere of the material at a given density will go critical on its own. Thus, you can have a solid subcritical chunk of a fissile material of a larger mass than that value, as long as it has a different geometry (e.g. shaped like a rod instead of a sphere). It's also possible to detonate a bomb with less than the "critical mass" of material — typically by the use of neutron reflectors.
11. Nuclear Explosion=Mushroom Cloud: Since All Nuclear Explosions is often related with mushroom cloud, a nuke will always make a mushroom cloud no matter how small it is, even in a vacuum. This is sometimes played for humor. Similarly, mushroom clouds are only created by nuclear weapons, rather than any explosions, if it's large enough. Typically, the size and duration of the fireball and mushroom cloud will also have no real relation to how powerful the weapon is supposed to be. Also, a nuclear explosion in a visual medium will often produce a series of vertical lines of smoke. These are copied from nuclear tests, but are not actually anything to do with the explosion; they're trails from rockets fired to give a visible indication of the shockwave. Even in places with an atmosphere, the visual characteristics of the explosion are highly dependent on the local medium; thus, ones exploded underwater, underground, on the surface, in an airburst relatively near the ground, or in the high atmosphere all have very distinctly different appearances.
12. Shockwave Inconsistency: In a manner also frequently applied to lightning and conventional explosions, even when a nuclear explosion is accurately depicted visually (dazzling flash of light, followed by a rising mushroom cloud and shock waves racing outwards across the ground destroying everything that is not already on fire), frequently it will be heard to produce a deafening roar from the outset, long before the shock wave reaches the camera. Since the shock wave travels somewhat faster than the speed of ordinary sound, the initial flash and subsequent fiery visuals should actually be silent until the wavefront hits, save for the damage caused by the blast's radiation. For any observer sitting far enough away from the explosion to stand a chance of surviving it, this delay should be quite noticeable.
13. The Power Of... Fission OR Fusion?: Fission is breaking up a heavy nucleus (usually uranium or plutonium) into two lighter nuclei, plus a few loose neutrons. Fusion is pretty much the opposite: joining light nuclei (usually hydrogen isotopes) into a heavier one (usually helium). Since fusion and fission-based technology are both atomic, nuclear fusion is depicted as the same as but more than nuclear fission. Plutonium is usually similarly depicted in relation to uranium. Also, in fiction, the existence of fusion-assisted nuclear weaponry is simply not acknowledged. All nuclear weapons, even those in the multimegaton range, run entirely off of fission. Typically, if a "fusion bomb" is talked about, it will imply that the device is extremely futuristic. The hydrogen bomb or "H-Bomb" is a fission-ignited fusion, or a "fission-fusion" bomb. Due to the high initiation temperature required for the fusion reaction to take place, this is known as a "thermo-nuclear" rather than a nuclear device. The term thermonuclear, while often applied to all fission weapons, correctly refers only to the fission-fusion or h-bomb type weapon. The difference between a fission weapon and a fission-fusion weapon is academic at best; immediately after WWII, most new A-bombs were made using "boosted fission" (in which a small fusion reaction is initiated in order to provide more neutrons and more efficient fission), and a "fission-fusion" weapon still derives most of its energy from fission. Most fission-fusion weapons use a cladding of uranium-238, which will absorb most of the massive number of 'unused' fusion neutrons and then fission; the bomb is now a 'fission-fusion-fission' bomb. Without that U-238 cladding, the neutrons spray out at high speed, irradiating the near area, and you have what the US called an 'Enhanced Radiation Reduced Blast' weapon — also known as the "Neutron Bomb". There are two main types of fusion bombs: the American Teller-Ulam type (also known as "Sakharov's Third Idea"), and the Soviet Sakharov type, also called "the layer cake". The Teller-Ulam bomb consists of a fission starter charge (often called the primary), a lithium deuteride fusion fuel block (often with the additional neutron source) next to it, clad by the U-238 "pusher" or "tamper" (the whole assembly usually dubbed the secondary), and the shaped heavy metal case. When activated, the primary emits a lot of hard X-rays that are reflected from the case to the secondary, ablating the tamper's exterior and causing it to compress, which in turn starts the fusion. Sakharov-type bomb has the starter completely surrounded by the fuel and the U-238 case, and the starter is optimized to emit mostly neutrons. When activated the neutrons are absorbed by the case, which then starts to fission, and the heat and radiation from the exploding case compresses and activates the fuel. It is called "layer cake" because layers of lithium and uranium could be repeated, increasing the device's output. All modern warheads use the Teller-Ulam system, as the "Layer cake" design was rather inefficient, but it let the Soviet scientists to create an upgrade of the American design, where the additional fission-fusion stages are added to the device, thus making it of theoretically unlimited power. The most powerful thermonuclear device ever detonated, The Tsar Bomba, was reportedly a three-stage device employed in a two-an-a-half staged configuration, with the tamper of the tertiary made of lead and not the U-238 to reduce the fallout. With the uranium tamper the bomb's projected output was 101.5 megatons, lead tamper reduced it to just ~50 Mt. To clarify: The "layer cake" design was abandoned as soon as the Teller-Ulam design had been arrived at (the US, the UK and the USSR all got it at roughly the same time, with a certain amount of help from espionage). Multi-stage devices are made of a cascade of Teller-Ulam stages, one Teller-Ulam stage acting as the primary of a larger Teller-Ulam stage. The cascade can be continued more or less indefinitely, but no more than three stages are required for any militarily useful yield. The Tsar Bomba - which was purely for show, and militarily useless - was a Teller-Ulam cascade. It is theoretically possible to build a fusion bomb without a fission primary, what would be referred to as a pure-fusion weapon. Proposed "alternate primaries" include exotic nuclear isomers, sufficiently powerful lasers or flux compression generators, or even minute quantities of anti-matter. Such weapons would theoretically have the advantage over Teller-Ulam devices in yield control and produce nearly no fallout. However current technological limitations mean none of these methods are currently within reach as even an experimental device, much less a practical weapon, leaving them in the realm of science fiction for now.
14. Meltdown In Fusion Reactors: Fusion power tends to be depicted as operating in exactly the same way as nuclear power; while the reactor set / prop might look futuristic, expect talk of chain reactions and meltdowns in relation to a fusion plant, even though neither term could possibly be applied to any practical nuclear fusion plant. Fusion reactions are not self-sustaining unless they happen inside a star; in fact, the ongoing problem preventing us from achieving a fusion-powered grid is that it currently takes a lot more constant energy influx to cause the reaction to happen than can be gathered by it. Additionally, the fusion reaction itself requires exceedingly delicate conditions, carefully maintained by massive electromagnets and vacuum pumps. As a result, instabilities, fluctuations or otherwise serious problems in a fusion reactor will merely cause the reactor to instantly and mostly harmlessly shut itself down. Alternately, fusion may be shown as a perfect, clean energy source that generates limitless energy from minuscule amounts of water. Not so in real life. Most proposed fusion reactions generate lots of neutrons, which in turn create radioactivity aplenty. Some possible fusion reactions are aneutronic, mostly or entirely avoiding this problem, but those produce less energy and are technically more challenging to achieve, as if making a viable fusion power plant of any kind weren't hard enough. While it's true that fusion is not radiation-free, the issue posed by the irradiated material is vastly inferior to fission reactions. Generally only the innards of the reactor become irradiated; given sufficient care, an ideal fusion plant would, from a practical point of view, be "clean". Anyone who stuck their head in the reactor would die gruesomely, but nobody outside the plant itself would need to concern themselves with such issues. Of course, this is also true of fission reactors. It would actually be about the same at the plant itself. The main source of radiation exposure for personnel operating a nuclear reactor is nitrogen-16, which is created when oxygen in water (you still have to cool the thing, and transport energy to your steam turbines somehow) is exposed to neutron flux. Neutrons will also irradiate iron and cobalt atoms in the primary coolant piping, providing the majority of radiation exposure in a shutdown, contaminating the coolant (thus requiring the same control methods needed as in a fission plant), and ensuring that all maintenance tooling and cleaning supplies are low-level nuclear waste (again, same control methods). However, the big difference between fission and fusion in terms of waste is the spent nuclear fuel; the nuclides created by the fusion reaction itself would be short-lived and tame compared to fission products. What WOULD be a perfectly clean energy source would be magnetic confined helium-3 fusion, as its byproduct is protons, rather than neutrons. This has two advantages: 1. A proton flux won't make the walls radioactive because it will be contained by the magnetic field. 2. Since protons are charged, a high energy proton flux IS an electric current, so it can generate electricity directly by induction, rather than requiring a steam plant. This avoids the nitrogen-16 problem and also dramatically increases the efficiency of the generator.
15. Glowing Nuclear Materials: Most radioactive materials don't glow at all . Swimming pool reactors have a characteristic blue glow that's actually Cherenkov Radiation — pretty, but not caused by the radioactivity itself. Some intensely radioactive substances like actinium, cesium-137, and pure radium metal itself (in large enough quantities), actually do glow (technically, self-fluoresce) by their own radioactivity and are generally not healthy to be in the same room with. However, even those are faint enough that you can only see the glow in the dark.Sufficiently hot masses of critical material, such as the fuel pellets for radioisotope thermal generators, do glow, but not out of radiation - merely out of heat. Also, your average picture of a glowing fuel-pellet typically cheats - most such pictures are taken after covering the pellet with a thermal insulator, concentrating its heat enough for the express purpose of making it glow and taking a pretty picture. You'd only be able to see the glow with an infrared-sensitive imager otherwise. Most radioactive elements are greyish, not green or blue. The most common (non-metallic) color of nuclear material would be from one of the first steps in uranium refinement; yellowcake. The "green glow" idea probably came from the greenish color of the old glow-in-the-dark radium dial wristwatches. Even in this case, though, it isn't the radium that's glowing. The hands and face are painted with a mixture of radium and zinc sulfide; the latter phosphoresces when struck by the high-energy charged particles emitted as the former undergoes radioactive decay. Another source of this idea is probably the "uranium glass", a colored glass very popular in the early 20th century. Its actual color and transparency varies from straw to grass-green, and from slightly dusty to completely opaque, but it invariably glows a solid yellow-green under the UV light.
16. Instakill Desolated Zone: Any amount of radiation renders an area a physically unapproachable deathtrap for thousands of years. Radiation, especially in videogames might approach lava in terms of lethality (well, assuming that we're talking about real-world lava rather than video-game lava). Anything this insanely radioactive would be decaying so rapidly it wouldn't actually be the same isotope for more than a few minutes. That's what radioactivity means. It's perfectly possible to walk around in the Chernobyl Exclusion Zone without dropping dead in seconds or growing a third arm. In the entire 30-kilometer zone, dangerous radiation is limited to two "hot spots" with a total area of 2000 square meters, and 'dangerous' means 'a picnic in this place might result in some radiation poisoning'. The zone become an accidental nature reserve. Not everything is roses, of course: the soil closest to the plant contains high levels of uranium (a heavy metal), and the food chain is still full of easily absorbed caesium-137 and strontium-90 (with a half-life of roughly 30 years, which means that even today about half of it remains after the disaster). So while they're mostly free from human interference, animals in the area have reduced lifespans and a high rate of birth defects. People live in Hiroshima and Nagasaki, despite the best efforts of a pair of horribly primitive and inefficient strategic nuclear weapons. Weapons that would have left a much larger and more concentrated amount of radioactive fallout than more efficient weapons. This is helped by a benefit of an air burst - if the fireball doesn't touch the surface, fallout is extremely small. If it does touch the surface, though, it's irradiating and vaporizing tons of dirt/water which then go up in smoke... and later come down, somewhere.
17. Superhero From Nuclear Accident: When radiation is supposed to "alter" (e.g. damage) DNA/RNA, it would have to introduce the same very specific change in billions, per body cell count, of random events hitting that DNA. Then, as a functioning body actually has far more regulating systems active, it should somehow alter all of them in precisely the same manner, so we do not get an old, boring real life set of radiation symptoms like body systems fighting in an attempt to fix each other. And not the least, the amount of radiation doing all that should somehow fail at destroying/damaging every other body chemical but DNA (rendering the whole organism inoperable) or simply frying the subject in the process.
The cold war ramps up the inaccuracies about nuclear technology, not only in energy-generation and weapon aspect, but also their policies regarding their usage
18. Counter-city Policies (Fail Safe): Only used by the larger powers in the early days of nuclear weapons ('50s-'60s), when there was no hope of guiding them to targets more specific than the general vicinity of the largest cities. Lesser nuclear powers like Britain, France, and the PRC continued these policies to make up for their smaller (less than 300 e.a.) number of weapons. The USSR and USA went on to target specific military and industrial targets ('Counter-Value' policy), but in practice there was little difference between nuking these and nuking cities - especially in places like the West Midlands of England, lower Yangzi, and Japan. While it is sometimes said that the US was less focused on hitting civilian targets than the USSR, this was actually because the Soviets built their military and industrial facilities as far from their civilian population centers as possible to minimise civilian casualties from 'Counter-Value' nuclear strikes. While the USA could have reciprocated, they considered the cost and morale-damaging effects prohibitive.
19. Soviet First Strike: The Soviet Union had a "No First Use" policy ( only use nuclear weapons if first attacked with nuclear weapons) in the 1980s. Before then, there were plans for first use, but only in response to an imminent Western attack. During the Cold War and post-Cold War analysis of East German, Czech and Polish documents, many people confused the term "pre-emption" with "first strike". Pre-emption is like this: it is considered self-defense to draw and shoot if the other guy starts to draw his gun first. While the Soviets had such a policy, it was a policy that could have been undone at the stroke of a pen by the Premier, so movies hypothesizing about a Soviet first strike aren't wholly irrational. (There was certainly a fair amount of fear among NATO that the no-use-first policy was just PR, certainly, regardless of how justified said fear was.)
20. The Rogue Launch: In general, Soviet Cold War weapons had coded locks (Permissive Action Link), requiring authorisation from the top commanders to be armed. During the Cuban missile crisis however, there were missile carriers capable of independent launch of armed missiles. On the US side, until the 1990s, it would have required at least three people to launch an armed attack from a submarine (and a missile launch from a submarine would be damned near impossible without the full support of the crew). Other launch methods had the coded locks. This system, however, only really existed after 1962. In the UK, on the other hand, until 1998 the RAF's nuclear missiles were secured with nothing more than a cylindrical bicycle lock key (It was a running gag that this made the UK the safest place in the world to store nukes because the key would have been lost almost immediately and you'd need fifteen forms and three Warrant Officers' permission, plus a three week wait to requisition a pair of bolt-cutters ). Royal Navy Trident submarines are still able to launch without a code since a mere ten minute warning meant that if a nuclear war had broken out, it is unlikely that there would be time to issue relevant orders to their submarine captains. Plus, no officer of the Royal Navy would ever consider acting without orders or the proper cirumstances. And all sailors work for the Queen, who would be utterly Not Amused. The sub commanders do have their orders: the letters of last resort written by the Prime Minister, containing orders on what action to take in the event that an enemy nuclear strike has destroyed the British government. Recently declassified data has revealed that the US protections vs. "rogue launch" pretty much only existed from 1961 onwards. In the 50s, there were no physical safety interlocks on US nuclear warheads, at least a half-dozen senior officers had the authority to launch a nuclear strike on their own initiative (said authority intended to be used only if a war situation occurred and the President was out of communication, but as with the Trident submarine example above the only real enforcement was the honor system), and in some cases, bomber units were under orders to attack Russia immediately if they ever stopped receiving periodic "don't attack" messages from HQ — i.e., the same situation as the fictional 'Fail-Safe' example. The US also had nuclear weapons stationed on foreign soil in countries like Italy and Turkey which had experienced military coups. Even with a two key lock system, there was nothing to stop the keys from being seized by force.
21. The Nuclear Button: Neither side in the Cold War had nor has a nuclear launch button, even in their "nuclear briefcase". The briefcase contain information about nuclear strategy, and equipment for the leader to communicate with, and authenticate himself to, the military personnel in individual silos (etc) who would actually carry out a launch. The Soviet/Russian nuclear briefcase, codenamed "Cheget", after a mountain the the Caucasus, is actually a communication terminal that's always online, and has been ever since the system was activated in 1983. If it ever loses connection with the "Kazbek" control system of the Strategic Nuclear Forces, it's regarded as a "Launch" command, because it's taken as a sign that its bearer is incapacitated. There are three such briefcases, one for the President , one for the Defence Minister and one for the Chief of General Staff. An actual nuclear strike requires receiving the command from at least two out of three devices.
22. Kidnapping President For Nuclear Launch Codes: No matter what Modern Warfare 3 told you, there's nothing right about the idea of "nuclear launch codes" that the President, or a similar official, has memorised. This is often used to establish a "race against time" scenario where the President must be rescued before some villain can extract the codes from him, or simply be why the President must not be allowed to be captured in the first place. In real life, the launch codes are written down (since you don't really want your country blown up without retaliation because someone can't remember a code) and usually kept in the nuclear briefcase, issue orders rather than allowing the direct remote launching of weapons, and would be changed if the President was compromised in some way anyway.
23. President's Order For Launch: The US President cannot launch a nuclear first strike without the cooperation of the Secretary of Defense or any other administrative official that's been appointed/approved by Congress (e.g., CIA director, most of the Presidential Cabinet...). Ordering a retaliatory strike was something a number of people had authority to do. The plane known as "Looking Glass" had authority to do so in the event that the National Command Authority was killed or out of contact. Were DEFCON to reach level 2, both pilot and co-pilot would be required to wear eye-patches in case a nuclear explosion render their exposed eye either momentarily or permanently blind. Nowadays they use goggles that instantaneously turn opaque when exposed to the bright flash of a nuclear detonation and then return to clear to allow the pilots to see clearly. While current policies are classified, it can be assumed that after a major strike on the USA, remaining weapons would be released, with or without higher command. For the Soviets, supposedly, the semi-automatic Perimetr system had three human operators who were able to give the order to launch all remaining warheads in case when on-site seismic detectors detected multiple nuclear explosions on Soviet soil and high command is inaccessible. The Perimetr is only a part of the larger all-encompassing Kazbek control system that also includes aforementioned nuclear briefcases, and it serves as its "fail-deadly" fallback that ensures that the retaliatory strike will be launched even if everyone in the chain of command is incapacitated. It is, however, in a standby mode normally, and is supposed to be activated only when there is imminent threat of an attack.
24. Using a Missile Warhead As a Stand-still Bomb: Since the Cuban Missile Crisis, virtually all nuclear warheads are designed so that they will only go off after being exposed to certain environmental conditions- as in the large numbers of Gs associated with a missile launch. This can be overstated, however; accelerometers and other arcane safeguards are intended to protect vs. accidents. If you deliberately intend to misuse a warhead in such a manner you would presumably have the knowledge and opportunity to simply remove the detonator mechanism and install a new one, or tamper with the existing one. The US nuclear weapons laboratories apparently think that their nukes could not be made to detonate without the codes, even if the labs themselves tried. To date, this has not been tested.
25. Nuclear Superpower: Most films behave as if only the USA and USSR (And recently, North Korea) had nukes. In reality the UK and France were also nuclear powers before the nuclear non-proliferation treaty. Later Communist China, India, Pakistan, and South Africa (probably joint-developed with Israel) produced weapons before the end of the Cold War. The Republic of China/Taiwan also made a bid for acquiring nukes in the 1970s-80s, but was blackmailed out of it by the USA. In an open secret, Israel is widely believed to possess nuclear weapons since the 60s or 70s (Something they still deny to this day, despite overwhelming evidence of the Israeli nuclear weapons program. Generally, everyone says they don't have them, while everyone knows they do. Israel's enemies publicly decry the fact that Israel is the only nuclear-equipped Middle East state, while the rest of the world brushes off such accusations. It's...complicated) Several European countries had American bombs stationed there too. South Africa disarmed in 1990, while it is an open secret that Pakistan is still making them. Iran and Syria are suspected by some of having nuclear weapons programmes also. Many European countries still have American nuclear gravity bombs stationed there - the Netherlands, Germany and Turkey among others. Their pilots train to use them; in the event of war, the US bombs would be turned over to local NATO forces. Although the Vela Incident was likely a simple equipment error on what was then an aging satellite, one the popular theories circulating about it is that it detected a real detonation - perhaps even a joint Israeli/South African nuclear test, as S. Africa was being subjected to multiple embargoes and sanctions due to Apartheid, and Israel was looking for a nation to help them gain nuclear capability because they were being embargoed by some countries in NATO. Note that while North Korea's interest in developing nuclear weapons goes back to the 1950s, the country did not test its first nuclear weapon until 2006. As such, North Korea did not have nukes during the Cold War period. And even so, it's by-and-large suspected that every North Korean nuclear weapon tested to date has been a fizzle (nuclear weapons parlance for a dud). It should be noted that a fizzle just means that the nuke didn't reach the expected yield, not that it didn't detonate at all. A fizzle (Usually caused by bad design, poor construction or inappropriate nuclear material) can still yield a blast measured in kilotons, with the largest fizzle, a failure of a fusion secondary during a 1 megaton nuke test, reaching an estimated 250 kilotons. Considering that it still means partial fusion was reached, the test was considered a partial success.
26. Disarming an ICBM Post-Launch: No matter what the ending of Modern Warfare told you, deployed strategic ballistic missiles do not have any mechanisms for the attacker to remotely disarm or destroy the weapons after launch (After all, you don't want your first strike being aborted because the enemy finally obtained the code), and use inertial guidance based their manoeuvres from a known initial launching position and so cannot be steered off-course either. For all intents and purposes once the missile has been fired it can only be stopped either by mechanical malfunction or interception (That's what anti-ballistic interceptor missile for). Missiles which are used for testing are modified with a self-destruct mechanism in case something goes wrong, but live warheads are not used for testing the missiles. Gravity bombs on the other hand did have this sort of thing, each was equipped with a scuttle charge in case the bomber had to drop its bombs to make it home. On some models the timer on the scuttle charge was designed to activate even in an aggressive drop, though considerably after the bomb would have detonated if it wasn't a dud (and the chances of a nuke remaining intact after trying to detonate are slim anyway).
