• Huge blast at Japan nuclear power plant - a partial nuclear meltdown has occured
    843 replies, posted
Yes, Mini, because Chernobyl was built up from garbage by some underpaid soviets. I don't think Japan's reactors are like that.
[QUOTE=MIPS;28576874]So [b]yes, there has been a meltdown.[/b][/QUOTE] Huh, doesn't seem to be that big according to NHK. The radiation levels that went over government standard are said to be only within the plant, but the locals are being evacuated in case of a full meltdown. I think it's a partial meltdown, unless the molten core missed all water around it when traveling downwards, but even then, that's a good thing, right?
[QUOTE=Recurracy;28578251]The power plant is located right within a heavily populated area, right? IF it's going to be a mini-chernobyl, I don't even want to think about the results.[/QUOTE] I'm pretty sure the whole area is already evacuated. [QUOTE=eggnogg13;28573719]Copypasta'd from /sci/: Just to make matters clear. The Soviet reactor and the Japanese reactor are of two different types. They operate differently, mainly in that the Japanese reactor is deliberately designed to passively run down if everything goes to hell. The coolant helps the reaction so when the coolant is turned into steam the fission reaction stops. The uranium is no longer being split and turned into matters more radioactive. Commercial uranium is not very radioactive and by itself can't achieve a critical mass that would cause a runaway reaction. So what's the meltdown about then? Well, the fission process generates a lot of heat to turn coolant into steam (a nuclear power plant is in a sense a steam engine) and the solid matter inside the reactor will retain heat even when the process stops. If the heat is hot enough it can melt the cladding that the uranium pellets are encased in. The melted reactor will fall to the bottom of the steel containment chamber enclosing the reactor. Hence "meltdown". In popular imagination this can cause a "China syndrome" where the hot lump of material melts through the containment chamber and bores down into the earth. However, this is an impossibility in western reactors, it's simply not hot enough to burn through the thick steel encasing. The real danger here is that the reactor leaks and various amount of highly radioactive fission byproducts escape. It appears a little cesium and iodine isotopes escaped when they let out steam to lower pressure in the reactor, but otherwise the dangerous content remains inside. In short, what happened at Chernobyl is an impossibility here.[/QUOTE]
Well, I guess that's sort of a relief. I'm just hoping nothing serious happens.
[QUOTE=Recurracy;28578305]Yes, Mini, because Chernobyl was built up from garbage by some underpaid soviets. I don't think Japan's reactors are like that.[/QUOTE] Actually it was BUILT right, but DESIGNED and OPERATED very wrong. Two different things there... The Japanese are far more advanced, and because of the reactor's design it shouldn't blow up like the Chernobyl one, but if something actually does go wrong, in any case the results should be less catastrophic, but due to population, they may be worse. Like if the fuel becomes exposed again, breaches the containment and deflagrates, then some serious shit is going down.
[QUOTE=lolnubs;28578418]Actually it was BUILT right, but DESIGNED and OPERATED very wrong.[/QUOTE] Ok, I'm sorry for being mis-informed. I swear I've read somewhere it was terribly built...
People are still overreacting about the whole nuclear power station thing. Safety measures have come leaps and bounds over what they used to be. We're not living in the sixties, Chernobyl is an impossibility nowadays.
[QUOTE=lolnubs;28578418]Actually it was BUILT right, but DESIGNED and OPERATED very wrong. Two different things there... The Japanese are far more advanced, and because of the reactor's design it shouldn't blow up like the Chernobyl one, but if something actually does go wrong, in any case the results should be less catastrophic, but due to population, they may be worse. Like if the fuel becomes exposed again, breaches the containment and deflagrates, then some serious shit is going down.[/QUOTE] Shouldn't it be a problem only if it reaches into direct contact with sea water around the plant?
[QUOTE=croguy;28578341]Huh, doesn't seem to be that big according to NHK. The radiation levels that went over government standard are said to be only within the plant, but the locals are being evacuated in case of a full meltdown. I think it's a partial meltdown, unless the molten core missed all water around it when traveling downwards, but even then, that's a good thing, right?[/QUOTE] Uhhh... no. Because if the molten reactor manages to melt it's way through the ground, it'll hit the water table, sprouting radioactive geysers of doom, which is probably worse than having the core burn up in open air. @ above post: Worse if it comes into contact with actual seawater (not that being flooded into the plant), because then the ocean will be irradiated... Like that lead poisoning from a factory that was dumping it's waste products into the ocean, which became polluted with lead.
[QUOTE=Recurracy;28578435]Ok, I'm sorry for being mis-informed. I swear I've read somewhere it was terribly built...[/QUOTE] It was terribly designed and thus one could argue it was built in an awful way.
[quote=Pander][B][U]Basic Nuclear Plant Safety Primer for Stupid Goons[/U][/B] The Fukushima Daiichi power plant is a Boiling Water Reactor. It is both moderated (what causes fission) and cooled (what stops the nuclear fuel/waste from getting so hot it melts) by water. The plant was scrammed (immediately stopped) after the earthquake by inserting control rods (boron-infused 'rods' that prevent further fissions from taking place (by eating up all the neutrons necessary to initiate fission). This happened successfully. The plant is "shut down." However, after the plant is shut down, there are still certain elements called "delayed neutron precursors" that will STILL released neutrons for some time period after the plant is shut down. These are what cause heat to accrue in a reactor that should theoretically be "shut down". This is why cooling needs to be provided in a typical 2nd generation light-water reactor (what most reactors in the world are) for a good while after shutdown. [B]Without cooling water[/B], the likely "worst case" will be the reactor pressure vessel (RPV) building up heat, which builds up pressure, which could cause a rupture of the vessel. The fuel rods will spill out radioactive contents, fires might break out, and the reactor is basically a lost cause. And how does that affect the general populace in terms of radioactive dose? -Not at all. The RPV is surrounded by a containment facility designed from the ground up to withstand everything short of hydrogen bombs. Given the semi-spherical distance from the RPV an explosion would have to travel to break through the containment vessel, it is fundamentally impossible (given the energy density the RPV is capable of containing) for there to be straight up "radioactive smoke" or such getting outside of containment. The containment building is constructed to prevent EXACTLY this emergency. So while this is a worrying emergency, and could represent billions of lost dollars a mess to clean up should the WORST come about, it will still not be another Chernobyl. And given the efforts underway to provide cooling and the fact that the fuel rods are still not exposed to air (When the real danger of fuel melting can occur), there is still time to stop this loss of coolent accident (LOCA). So we SHOULD worry about this reactor problem, but not for the reason most anti-nuclear activists would have you believe.[/quote] he's a nuclear engineer fyi [url]http://forums.somethingawful.com/showthread.php?threadid=3396092&pagenumber=184#lastpost[/url]
[QUOTE=BAZ;28578436]People are still overreacting about the whole nuclear power station thing. Safety measures have come leaps and bounds over what they used to be. We're not living in the sixties, Chernobyl is an impossibility nowadays.[/QUOTE] People always get scared when there is talk about radiation. After all, 61 people died directly because of the chernobyl. All of em were PP-workers and firefighters. (badly equipped and some of the PP-workers died because of the explosion) Nobody off-site suffered from acute radiation effects, so people exposed outside the NPP area had only a possibility to get a thyroid cancer. And thyroid cancer is usually not fatal if diagnosed and treated early.
Exactly, there are less than something like 20 civilian deaths attributed to chernobyl radiation across europe and that's mainly because they refused to leave their homes and continue sucking nuclear dust.
[QUOTE=lolnubs;28578450]Uhhh... no. Because if the molten reactor manages to melt it's way through the ground, it'll hit the water table, sprouting radioactive geysers of doom, which is probably worse than having the core burn up in open air. @ above post: Worse if it comes into contact with actual seawater (not that being flooded into the plant), because then the ocean will be irradiated... Like that lead poisoning from a factory that was dumping it's waste products into the ocean, which became polluted with lead.[/QUOTE] I see. Well, there must be some sort of a way to stop the core from melting it's way through, right?
[QUOTE=croguy;28578604]I see. Well, there must be some sort of a way to stop the core from melting it's way through, right?[/QUOTE] You're asking if there's a way to stop the core from melting through concrete and steel. It's gonna take a lot of sea water man. A fucking lot.
[QUOTE=lolnubs;28578450]Uhhh... no. Because if the molten reactor manages to melt it's way through the ground, it'll hit the water table, sprouting radioactive geysers of doom, which is probably worse than having the core burn up in open air. @ above post: Worse if it comes into contact with actual seawater (not that being flooded into the plant), because then the ocean will be irradiated... Like that lead poisoning from a factory that was dumping it's waste products into the ocean, which became polluted with lead.[/QUOTE] I see. Well there must be some sort of a way to stop the thing until it reaches the water bed, right?
[QUOTE=bravehat;28578560]Exactly, there are less than something like 20 civilian deaths attributed to chernobyl radiation across europe and that's mainly because they refused to leave their homes and continue sucking nuclear dust.[/QUOTE] Could have installed some kind of air filters couldn't they? Or just wear gas masks to bed... IMO anti-nuclear people are totally dumb, a light-water reactor like this one is actually a fucking good thing then... So long as they can stop any disasters, and prove to the world that despite the facility being bashed by earthquakes and suffering a semi-LOCA, then maybe all of the coal power plants will be replaced by these reactors. I mean, WA is "nuclear free". So we have a power-plant spewing thousands of tonnes of CO2, where a simple little reactor like this could provide cleaner power, and at least there has been some time to evacuate everyone IN CASE of this reactor failing... [editline]13th March 2011[/editline] [QUOTE=croguy;28578633]I see. Well there must be some sort of a way to stop the thing until it reaches the water bed, right?[/QUOTE] Well, if they put water on it, the fucker will just get hotter, so they need to dope that shit with boron. They can't dig under the reactor or anything, they can only watch, wait and hope that they can cool it down before it actually melts through anything. But at the current rate, the top of the control rods have melted... wow. The cores are going into meltdown, let's hust hope they can stop the thing before the whole core is liquid. But i don't like the idea of sodium chloride being present in the makeshift coolant, you know what happens when you boil away seawater. You get salt. If any salt deposits start forming up, there is potential for even more problems :frown:
[QUOTE=lolnubs;28578657]Well, if they put water on it, the fucker will just get hotter, so they need to dope that shit with boron. They can't dig under the reactor or anything, they can only watch, wait and hope that they can cool it down before it actually melts through anything. But at the current rate, the top of the control rods have melted... wow. The cores are going into meltdown, let's hust hope they can stop the thing before the whole core is liquid. But i don't like the idea of sodium chloride being present in the makeshift coolant, you know what happens when you boil away seawater. You get salt. If any salt deposits start forming up, there is potential for even more problems :frown:[/QUOTE] Boron seems like a good option. They could also pour additional coolant on it in case if it can't take the heat, right?
[QUOTE=lolnubs;28578657]Well, if they put water on it, the fucker will just get hotter, so they need to dope that shit with boron. They can't dig under the reactor or anything, they can only watch, wait and hope that they can cool it down [B]before it actually melts through anything.[/B] But at the current rate, the top of the control rods have melted... wow. The cores are going into meltdown, let's hust hope they can stop the thing before the whole core is liquid. But i don't like the idea of sodium chloride being present in the makeshift coolant, you know what happens when you boil away seawater. You get salt. If any salt deposits start forming up, there is potential for even more problems :frown:[/QUOTE] Which is why all western powerplants have reinforced the reactor pressure vessel on the bottom area. The molten core failed to penetrate the reactor pressure vessel on The Three Mile Island accident, so it's unlikely that the China Syndrome would happen here. And Japs have flooded the first reactor with seawater, stabilizing it.
The reaction was already killed wuth boron control rods, they're just trying to keep it cool now so that a spontaneous fission reaction doesn't kick off, and they're using boron doped seawater as a coolant right now and as far as i know they're directly applying it since the cooling system is fucked.
[QUOTE=bravehat;28578746]The reaction was already killed wuth boron control rods, they're just trying to keep it cool now so that a spontaneous fission reaction doesn't kick off, and they're using boron doped seawater as a coolant right now and as far as i know they're directly applying it since the cooling system is fucked.[/QUOTE] Oh, well it seems that the situation is safer than it seems, then. Of course, they still have to carefully control the reactor's heat and there's no coolant system running.
Yeah, they should have it pretty much under control now, just gotta turn theur attention to the other tower that is apparantly on the verge of melt down.
Atleast it wont be like Chernobyl. Nuclear disasters suck.
I guess they better start dropping sand on it just like at Chernobyl.
[QUOTE=P1X3L N1NJA;28579065]I guess they better start dropping sand on it just like at Chernobyl.[/QUOTE] Better idea. Use boron doped sea water. HEY WAIT THEY'RE ALREADY DOING THAT! Who'da thunk it? v:v:v
Boron doped sea water is indeed the best possible option right now. For one it doesn't heat up anymore and stays cool as long as more boron water is thrown in it. Now about the other tower, that might be more difficult since the damage there wasn't light, to say.
[QUOTE=Hamushka11;28559281]Chernobyl v2[/QUOTE] I posted this exactly in another thread and I was rated dumb. :bravo:
[QUOTE=lolnubs;28575830]That's [b]if they overheated[/b]. Also if that structure collapses, [b]the reactor may still blow right up in a massive explosion,[/b] no one can fully say that any nuclear reactor is safe, unless it's deep underground (i'm talking 50Km or so), and even then a thermo-nuclear explosion would still fuck shit up. [/QUOTE] No it can't. What would blow up? Moderating fluid is water there and afaik there is nothing to stop pressure from getting released. A nuclear explosion cannot occur with that grade uranium. Stop pulling these arguments out of your ass.
It melts down and releases a lot of radiation, it doesn't blow up. Anyways, isn't it under control now anyways?
This won't be anything like Chernobyl, the design of the Chernobyl power plant meant that the top of the reactor could be removed to harvest fuel and weapons material. An explosion like that at the Japanese plant happen and blew the lid of the reactor off (something not possible now as reactors are fully sealed in a contained unit) allowing radiation to escape easily causing such the widespread effects it had.
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