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Should that one Powerpuff Girls episode get a mention for the "instant radiation mutation" variation of this trope? You know, the one where some guy working in a nuclear plant accidentally spills some glowing green stuff, wipes it up with his napkin, then promptly uses it to wipe his face causing spontaneous tentacle growth and so on? Then a fly lands on it and mutates into a bigger fly, lands in a pot of glue, then the glue-eating kid eats both the fly and some glue and turns into a giant glue monster? Man, typing that all out really emphasizes the ridiculousness of this particular example, even by kiddy cartoon standards.
Removed the following Natter from The Iron Giant example in the Films - Animation folder.
I'd just like to point out that "the rods promptly blew the fuck up. It was not actually a nuclear blast, it just threw radioactive shit everywhere." is way informal even for this wiki, but as it's the most succintly efficient way of explaining Chernobyl that I've ever read, I feel compelled to leave it in place.
I was looking at Wikipedia's entry on Nuclear Meltdowns. The first line on the page is this:
"Nuclear meltdown is an informal term for a severe nuclear reactor accident that results in core damage from overheating. The term is not officially defined by the International Atomic Energy Agency by the U.S. Nuclear Regulatory Commission. However, it has been defined to mean the accidental melting of the core of a nuclear reactor, and is in common usage a reference to the core's either complete or partial collapse."
Evidently, a pretty loose term. To that end, I have a question about nuclear meltdowns occurring in fission vs. fusion reactors. Right now, the article says that meltdowns are exclusive to fission reactors, presumably because fission reactors possess a danger of "runaway" reactions and fusion reactors require precisely controlled conditions to operate at all.
So meltdowns wouldn't happen to a fusion reactor by accident. But what if someone was deliberately attempting to cause a meltdown to damage or disable the reactor as in the Mass Effect 2 example? If that someone had access to the computer and equipment controlling the reactor, it seems plausible to me that they could damage it by overheating, which seems to qualify as a meltdown according to Wikipedia. I know very little about the design of modern fusion reactors (much less whatever designs they use in science fiction) but the Fusion Power article mentions lithium being used as a coolant, so I assume excess heat is a real concern.
No whiz-bang nuclear physicists eager to dazzle me with their knowledge and experience?
^While "runaway reaction" isn't a concern for fusion plants, whether a failure of the magnetic containment would be harmless is another issue. Basically, if there is enough hot gas in the plant, it will simply explode.
A fusion reactor cannot melt down because there's simply nothing to melt.
What melts in a meltdown is the fuel (the fuel assemblies are what make up the core of a fission reactor). And whereas a fission reactor contains fuel enough to last it for years, a fusion reactor contains only the fuel it needs right now - like in a gasoline combustion engine, it's injected as needed.
To add to that, the fuel in a fusion reactor is gaseous at room temperature...
So in conclusion: while you can think of many spectacular ways that a fusion reactor can fail, a meltdown isn't one of them.
...That really sounds sketchy to me. You're making it sound like the fuel melts but nothing else is damaged. If there's enough heat the melt the fuel, surely there's enough to damage the physical structure of the fuel rods and whatever other assemblies are inside the core. A quick Google search reveals uranium dioxide doesn't melt until almost 3,000 degrees C. I'm skeptical of you saying there's "nothing to melt" when there's solid matter and lots of heat in both fission and fusion reactors. Even if the fuel itself doesn't melt, damage to other elements of the core by excess heat sure seems to quality as a meltdown by Wikipedia's definition.
Also, as I said, this wouldn't be due to a random accident. It would be due to someone having full and deliberate control of the reactor, including the fuel injection systems.
I don't know how on Earth you got to "nothing else is damaged" from what said, but I'll try to explain again.
The whole idea of meltdown being A Thing is because a fission reactor has tonnes of (solid) fuel inside that produces massive amounts of heat - and continues to do so after the excrement has hit the ventilator, for quite a while even after/if you stop the actual fission. This mass, if allowed to melt, will start melting through pretty much whatever is in its way until you manage to cool it back under control.
Fusion OTOH works with gram amounts of (gaseous) fuel, anything that goes wrong will stop fusion from occurring, and as soon as the reaction stops, so does the heat production.
That you can melt components of a fusion reactor doesn't mean it's a meltdown. You can melt the pistons of a combustion engine - that doesn't make it a meltdown.
Original poster of the example here. Basically, I put it there because it's a terminology mistake. As ActualScientist pointed out, "meltdown" specifically refers to the fuel rods melting down. Fusion reactors don't have fuel rods, so this falls under "fusion = fission BUT MORE!"
Besides which (and yes, I'm going off on a tangent), any intelligently designed fusion reactor (which admittedly is rare in sci-fi) would have hardware failsafes (using the bare minimum fuel flow to keep the reactor running, the deadman switch principle, etc.) to prevent the kind of tampering of which EDI speaks. Even the Star Trek Technical Manual basically says that core ejection failures so often seen in TNG equate to the writers not reading their own reference material: they're electromagnets holding the core in place and require power to not work. Realistically, the best EDI could do is trip the failsafes and cause the reactor to shut down (which still leaves the ship without power, so the Normandy comes out on top anyway).
Yeaaaahh. I've played some Resident Evil (albeit not 2 or 3), and even I'm baffled.
I'm somewhat confused by the "1 light year" references. Is the edge of the solar system really that far?
Depends on how you define "edge of the solar system". The outermost planet, Neptune, is around 30.5 AU (1 AU = the mean distance between the Earth and the Sun), or 0.0005 light years, away from the Sun at its farthest point. The heliosphere, a volume of space filled with a medium emitted from our sun, extends out to around 100 AU (0.002 light years) at its closest end. If you include the Oort cloud or simply define it as the radius in which our sun dominates the gravitic influence, however, it's around 1 or 2 light years...
It doesn't really matter though. The second troper was merely using light years as an example to show how absurd the premise is.
I can't tell if the second half is contradicting it or expanding.
Neither. It's basically trivia... that mixes facts (Wells was inspired by science at the time and Bethe did pioneering work on stellar nucleosynthesis) with science fiction ("Bethe solar phoenix" is, AFAIK, a term invented by H. Beam Piper, and the nuclear processes in the sun bear no resemblance to what Wells describes).
The original entry should be re-added.
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How well does it match the trope?