TEPCO Confirms Partial Meltdown of No.2 and No.3 Reactors 209
blau writes with an article in NHK World. From the article "The operator of the crippled Fukushima Daiichi nuclear plant says findings show that fuel meltdowns may have occurred at the No.2 and No.3 reactors within days of the March 11th earthquake. But it says both reactors are now stable at relatively low temperatures."
TEPCO is also now blaming the tsunami for most of the damage rather than the earthquake.
relatively low temperatures (Score:4, Insightful)
Relative to what? The sun?
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Relative to what they'll eventually admit they were.
Seriously, is anybody else getting sick of this constant down-playing the severity of the situation? I understand the idea that you don't immediately run to the worst-case scenario and cry that the sky's falling, but this is ridiculous.
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Is it downplaying, or simply a lack of insight as to what's going on inside there?
Re:relatively low temperatures (Score:5, Informative)
Re:relatively low temperatures (Score:4, Insightful)
Yeah, that was fairly obvious. You don't need to be a nuclear scientist (just someone who knows what historical accidents have been significant, which ones haven't, and what made the difference) to realize that TEPCO weren't being honest, but it helps if you are to understand what they were being dishonest about.
What bothers me, more than TEPCOs dishonesty (which, frankly, is only to be expected when a company relies on image as much or more than products), is the number of people here who went around marking those questioning TEPCO statements in previous discussions as trolls. Sorry, but the science doesn't leave much room for debate. It seemed to be mostly by pro-nuclear fanbois who failed to understand you could be ok with the technology but suspicious of the implementors. I hope they are now willing to admit their errors and apologise for their abuse of the moderation system.
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I hope they are now willing to admit their errors and apologise for their abuse of the moderation system.
Come on, low 4 digit ID, did you forget we are on slashdot?
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Everyone is entitled to one fantastical hope beyond any possibility of it actually coming to pass. For example, there are still people on Slashdot who hope to form relationships or understand the more obscure Doonesbury cartoons.
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You could be ok with the technology but suspicious of the implementors.
Finesse has been a quality seldom seen here. Here, let me feed a troll: That position is like supporting the death penalty in theory but thinking the criminal justice system is far too primitive to mete it out fairly.
In the end, you have gawker and freerepublic and the moderates are completely drowned out by the mouth foam.
-l
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Re:relatively low temperatures (Score:4, Insightful)
But for weeks afterwards, major news sources have run headlines like 'Reactor 1 known to have melted down, reactors 2 and 3 possible, ', even though it sounds like "possible" meant "overwhelmingly probable, on a par with the sun rising tomorrow, but we haven't actually gotten photos to confirm it yet, or at least we've carefully avoided showing them to the guy making this statement.". The general public is going to be influenced by those sorts of headlines without ever seeing the actual status updates,
I'm personally for building safely designed reactors under responsible management - trouble is, TEPCO has shown they are not in any way what I would call responsible management. The nuclear power industry may survive the blow of having major accidents like this, but can it survive being associated with such incompetence, overwhelming lies and arrogance?
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There are more dangerous things in the world than not knowing exactly what is meant by "relatively low".
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Yeah, so you double- and triple-check it. But at some point "looks like things have been worse than we'd previously thought" starts to sound suspiciously like "looks like things have been worse than we'd previously admitted".
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Then you run into the possibility that you are wandering into conspiracy theory land. They might not be admitting things, but at the same time they might have had no clue either.
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at the same time they might have had no clue either
When all the real nuclear experts are joining with the armchair nuclear experts and saying "you know, there could very easily be a much bigger problem here than they're admitting to", the people who are actually supposed to be experts who are operating this particular nuclear power plant (and who we're sort of relying on to properly handle the situation and hopefully foresee and deal with its complications) don't really get to use ignorance as an excuse when everyone finds out "hey, apparently things were m
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You have no proof that they're deliberately covering things up. So at best it is conjecture to be kept at arm's length, not believed wholeheartedly.
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True enough. It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. However, in this case, this is the more useful quote: Each fact is suggestive in itself. Together they have a cumulative force.
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Like that time Tepco ran a geiger counter on a piece of material and found a radiation spike 10 million times above normal?
Yeah, so you double- and triple-check it.
No, at the radiation level that they thought they had measured, you run.
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Re:relatively low temperatures (Score:5, Insightful)
It's on both sides of the fence.
Some article came out shortly after stating that the radiation being emitted into the atmosphere was X% that of Chernobyl... when it was really 1/10th the percentage stated. You have people spreading panic and fear, as well as people saying "see this is why nuclear power is evil."
Meanwhile you have people there saying "no alarm, nothing to see here" and later that day we find out something major happened or people were being burned by the radioactive water.
So you have fear mongers and people trying to sweep it under the rug. It makes it very hard to get an accurate picture of what's going on.
Re:relatively low temperatures (Score:4, Funny)
which is *WHY* TEPCO is waiting until things have been confirmed before releasing news. It's not like they've actually hidden anything, they are just no releasing every factoid as-it-happens - but that's to be expected, because they are not fucking CNN. They have a responsibility to release accurate information to the ability possible, which is more important than releasing a new fact every 15 minutes - they aren't on Twitter either, for the same reason.
While they shouldn't downplay serious problems, they should be conservative in their news releases so as not to raise panic for no reason.
You forgot to add "This post Copyright TEPCO PR department."
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I have to agree you don't spend your time talking best case or worst case, you spend your time talking about the most likely case. I think its pretty clear TEPCO went best case on just about every issue.
You see this often when companies face these sorts of disasters, somehow they think its better to keep having to revise. All that does is make them look they not only don't have control over the situation but don't even understand it. BP did with the spill, its only leaking 20K barrels, well ok it might b
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What downplaying? We've known about the partial melt for quite a while now. This is just confirmation.
When the more panicky parts of the populace and media are imagining smouldering glow in the dark radioactive zombis and millions of bodies being bulldozed into a mass grave, I suppose simple facts do come off as downplaying.
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100C is relatively low compared to the temps required to melt the fuel. But it's still hot enough t
Re:relatively low temperatures (Score:5, Informative)
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The heat has to be caused by the level of neutrons striking fissile material. It's the only source of energy beyond the natural decay. Ergo, to reduce the heat is going to require absorbing neutrons. At 200'C, the water will turn to steam but the boron won't be doing anything, giving you a nice coating. It might do something, depends on what it's like inside.
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Relatively to temps enough to cause more damage (Score:3)
Termal camera measurements, and instrumentation show that the temps inside the reactor pressure vessels are at 270 C max, bad because that means that still is coming radioactive steam from the damaged reactors, good since that means that even if most fuel has melted, it didn't became a bloob of molten fuel damaging even more the reactor pressure vessels, meaning that as bad has is has get up to now, we are not dealing with the fuel out in the open like in the case of the Chernobyl disaster. The submission w
New news? Don't think so (Score:4, Insightful)
Many of the status reports from early on indicated a partial meltdown. (It was described as "fuel damage" - but that's meltdown).
So how is this news? We already knew the fuel rods had suffered from partial melting/damage. It's almost a given when you see status reports indicating fuel with only partial water coverage.
Re:New news? Don't think so (Score:4, Funny)
You don't get it. It melted down. That means that no one can live in Japan ever again. Millions will die, This disaster makes the actual Earthquake and Tsunami seem like nothing!
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Are you claiming that there is 600 tons of fuel in each of these reactors?
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I was thinking about making a Godzilla joke, and then I read this. Reminded me of how bad the whole situation is. I feel like a jerk.
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If anything is funny, it is your comment. Burnup? Care to define that?
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In the initial days of the reactor problems, there was concern that some of the core in reactor #1 might not have been fully covered by water, and that some fuel damage may have resulted -- as in a part of it. The claim was that a relatively small fraction was affected before they restored cooling water levels to normal levels, and that the core, while damaged, was largely intact. The "news" over the last week is that the entire core was uncovered for hours (the gauges were not functioning properly under
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I'm replying to too many posts in this thread, but again I feel compelled to do it. I watched the TEPCO news reports on TV. I live in Japan and I speak Japanese. It's possible that I misunderstood some things because it is a technical subject and while I am fluent in Japanese, these things are difficult. But your account of the events do not mesh with my recollection at all. This is from memory, but I recall them originally claiming that a large portion of the core had been left exposed for 5 hours. A
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...and it provokes serious questions about the ability to monitor exactly what's going on inside a reactor during a crisis. If you couldn't reliably tell that the reactor was actually in the process of melting down, then how can you react to the situation appropriately? It's like having faulty instrument readings while you're trying to safely land a plane with no visibility. The TEPCO crew could be the best reactor operators in the world, but if they don't know what is going on in there, they would be thoroughly borked.
The sad part of the story is that TEPCO crew apparently knew enough to figure out what was going on (whiteboard photos prove this), but officially they pretended they didn't know and simply omitted strongly suggestive datapoints from public releases. Only now, when enough isotopes have been blown around northern hemisphere that any interested scientist can sample the isotope ratio in the air and work back the numbers they slowly admit some truth, while still covering up what really exploded in reactor numbe
"Confirms"? (Score:2)
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I was kind of wondering why the "probably was a tsunami" thing was news, honestly. I thought everyone knew that starting 2 months ago.
This entire story seems like a repost of a repost.
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There are two things that are news here (albeit a little bit late). The first is the extent of the melting. There was always a question as to whether the fuel had melted or if only the cladding had melted. Early on a British scientist wrote an opinion that the data indicated that the fuel had melted completely. TEPCO responded saying that it was a possibility, but that the data could also support the situation where only the cladding had melted. When they finally were able to get inside the building of
Now blaming? (Score:5, Insightful)
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I think you're correct. The earthquake knocked out the main power lines, so the power switched over to the generators, and then the tsunami knocked those out. After that, the battery backups could only last so long. The only thing worse would be if an asteroid hit 10 minutes later. A perfect storm of "oh, hell...."
Tepco's Just Looking for a Scapegoat (Score:3, Interesting)
The Tsunami knocked out the power, but if it knocked out the valve control systems and pumps, why didn't all three reactors melt down at the same time?
How come they started overheating when their back up batteries ran out of power. With the first reactor's batteries failing earlier due to tsunami damage. Mere coincidence? I think not.
http://en.wikipedia.org/wiki/Timeline_of_the_Fukushima_I_nuclear_accidents [wikipedia.org]
The reason the reactors overheated and melted down was because power was not restored to the reactors' emergency cooling systems before their batteries ran down. If Tepco didn't try to handle everything internally for the first few days, they would have gotten power hooked up to the cooling systems much sooner. The Japanese Self Defense forces could have flown in some generators if requested and if they didn't have any I'm sure the US Military would have been glad to help out and airlift a few generators to help avoid a nuclear meltdown.
The key is that Tepco didn't request any aid from outside sources till it was too late and was forced to by the Japanese government.
From what I can see it's a case of ineptitude by Tepco employees that made this situation much worse than it should be been.
Re:Tepco's Just Looking for a Scapegoat (Score:5, Informative)
Unit 1 is a 460 MW reactor. Units 2 and 3 are 784 MW reactors. They have totally different ratios of heat generated to cooling capacity. This is why you're seeing reports for unit 1 coming separately, while reports for units 2 and 3 are (generally) coming concurrently. (The rest of your stuff about TEPCO being negligent, I agree with.)
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The batteries are there just to power things while the diesel generators are being turned on, usually they are used just for some minutes. It is much easier to keep a diesel generator running for days or weeks than to use batteries for that, and diesel takes less room that batteries and can be easily refilled while the generators are running.
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I will note that any unintended reactor experiment where 3 out of 3 operational reactors have almost an hour to shut down gracefully (before the tsunami hit and power was cut) and still manage to melt down is a pretty big failure by all sorts of measures,
I suggest you use measures that aren't biased against condemning TEPCO out of hand. That "reactor experiment" would not duplicate the environment of a magnitude 9 earthquake and subsequent series of tsunami.
especially when the tsunami was within the range of historical ones, such as the one that happened on this coast in AD 869. It's way too early to tell if there was an operational failure on the part of TEPCO, but it was certainly a design failure not to be prepared for events within the scale of historical ones at that site.
That information apparently didn't come out till 2001 (according to the paper, "The 869 JÅgan tsunami deposit and recurrence interval of large-scale tsunami on the Pacific coast of northeast Japan"). So how do you design a nuclear reactor for information that comes out thirty years later? And why do
bad title (Score:2)
Since when is "may have" the same as "confirms" ?
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You must have loved the title on another recent Slashdot article, "Swiss to End Use of Nuclear Power", which despite the very conclusive sound of the title, was really about some people in the Swiss Government *talking* about trying to get the Swiss to stop using Nuclear Power. Nothing had at all been passed into law or set as official government policy yet.
I've long since given up worrying about Slashdot titles. They're almost worthless, except to give you a general sense of what sort of topic you're deali
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Since when is "may have" the same as "confirms" ?
Let me translate:
An accident may have occurred: We had an accident, but don't know how bad it is.
This might affect civilians: If for sure will affect civilians, but hopefully not at a scale significant enough to change things.
We are looking into the possibility of evacuations: My family is already out of here, but getting you out is too expensive.
Nuclear energy is still the safest energ
Did trying to prevent meltdown, make things worse? (Score:2, Troll)
As I've watched the news about Fukushima, I have wondered if by trying to avoid fuel meltdown, did they make matters *worse*?
I admit, I really have limited knowledge about what went wrong or could have gone wrong. I'm definitely not a nuclear engineer.
But, from the news, it seems like the biggest source of problems was caused by hydrogen explosions. The hydrogen explosions happened because steam from the cooling water, under high heat and pressure, interacted with the Zircalloy fuel cladding, which caused t
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The problems are multiple.
1. Is the containment vessel solid? Will this burn through?
2. If the melted fuel gets hot enough to burn you will get radioactive smoke, and such into the air.
3. You are reducing the shielding to nearby people, by removing water that would be in the way.
4. If you made the wrong and not industry standard choice, do you go to jail?
Probably lots of other issues as well.
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1. Is the containment vessel solid? Will this burn through?
If the answer to that is "no, yes", then it isn't a containment vessel.
2. If the melted fuel gets hot enough to burn you will get radioactive smoke, and such into the air.
If it's exposed to oxygen, or the air, it isn't in a containment vessel, or you blew it open by putting water in.
3. You are reducing the shielding to nearby people, by removing water that would be in the way.
The water is not for shielding. The water is for cooling.
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How do you plan on getting all the air out? What equipment exists on side for getting a vacuum in the vessel?
Yes, if containment is lost then the fuel actually burning, as in oxidization at a rapid rate, becomes a real concern.
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The problem is that it could melt through the earth into the water table. Imagine what would happen if something that hot and dirty melted its way into the water table... untold radioactive steam explosions would then ensue!
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Yeah, no. It would have to burn though a huge amount of earth. Not gonna happen. If it got through the concrete slab that would be bad enough. Contaminated water would then seep into the water table and the water supply might be made undrinkable.
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Death-tole? (Score:2)
I am wondering how many people have died from this disaster and add the deaths due to Uranium Mining. And I would like to compare it to people who have died in Coal mining and coal power plant accidents.
Re:It would be funny if it weren't so damn serious (Score:4, Insightful)
Well, I haven't heard of any 3rd parties reporting anything unusual or notable regarding radioactive contamination above or beyond what has been reported already (and TEPCO can't exactly hide stuff that escapes the site.) Surely if it were so horrible then there would be accurate and reasonable reporting on the "true" radiation levels rather than what is reported, but I'm not seeing anything. And anecdotal rumors and information being spread via social networks (especially in a country like Japan that loves rumors) is suspect.
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You do realize that the deaths due to radiation from this incident are well... zero. This was no Chernobyl. Yes, the immediate area will likely be unsafe for some time, but by any rational measurement, the worst that happened was the tsunami, which sadly has been pushed to page 5 by "OH MY GOD, RADIATION LEAK, GODZILLA ATTACK IMMINENT!!!!"
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Maybe you need to tone down your sensationalism as well.
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The long term effects of this to the population: Nothing.
So those people are back in their homes and spending money in their local economies and the children are not having their education delayed and their parents' jobs are going swimmingly?
While they may not get cancer for another 40 years because of this, the economic statistics won't add up to "nothing".
This isn't to say that this accident is a reason not to install nuclear power. Far from it. But it is proof that certain people have in the past done little to ensure robustness in nuclear systems, and peopl
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The problem is the possible cost to the community is so high it might as well be 0. By that I mean if the possible cost is 1000 times what the plant is worth, it makes it less important to add more safety than if the possible loss was 0.5 times the value of the plant. In the latter case they might actually have to pay. So knowing they can't be made to pay they can take larger risks.
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There's a difference between "can't be made to pay" and "can't be made to pay the whole thing."
They can be made to pay as much as they can afford. If they think that's worth risking, then they're just crooks.
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Which means after the risks hit 1 x "What they can be made to pay", there is no economic incentive to ensure any more safety. Then add in that the company will be paying not any individual losing his savings and you get into a position where the people making these decisions may well be the ones least impacted. If an engineer makes a mistake that causes an event like this he is never going to work in that field again and is going to be working flipping burgers. If a CEO makes a decision that causes an event
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relative to this, I should note that I spent the last week at the NIH. One of their local newsletter articles included the results of an ongoing survey of possible thyroid cancers among the youth in the immediate area of effect of Chernobyl.
Results? A TOTAL (not increase) of 62 thyroid cancer cases in the relevant population.
Re:It would be funny if it weren't so damn serious (Score:5, Insightful)
The long term effects of this to the population: Nothing. The levels are so low for the population that they're laughably small.
Don't pretend like 0 is the number of people affected by this meltdown. Nobody has been "laughing" since they got kicked out of homes they lost millions of yen for. It's not like someone's going to give that house back to them, nor their cash. School closings smack in the middle of the Japanese school year also mean lots of disrupted youths.
With Japan's prior issues with unemployment, fukushima was the straw breaking the camel's back for many souls now banned from living somewhere safe and known to them. But nobody is talking about the local lives in the cone of influence of the actual meltdown.
Because, you know, all gunshot wounds only hurt locally and we can just ignore the pain if we concentrate on the body parts not hurting. Right?
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Yeah, you're right.
Dragonball Z will be real!
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Fossil fuels are more dangerous.
Nukes can be done safely, they just weren't in this instance, and the designers of this plant are directly to blame for that.
Apples and Oranges (Score:3)
Really?? Are you serious???
You should know very well there's a big difference between nuclear medicine and what was released by the Fukushima reactors. If you don't please beg your parents to send you to a different school before it's too late.
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Your comment said Radiation, it did not exactly seem to differentiate.
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Every material emits some level of radiation. It should go without saying they are not all equally dangerous. You think it's necessary to qualify that?
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I think when speaking in general terms like you are doing you should not be surprised when someone calls you out on it. You are acting like chicken little here.
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Well, yes, since no material can exist at absolute zero, all materials emit some form of radiation. And, yes, they aren't all equally dangerous. The danger also varies with context. Alpha particles are of no particular significance externally, but an alpha emitter that is ingested can cause serious damage. A high energy gamma emitter is usually nasty no matter where it is. You've also further complications (radioisotopes can also be toxic in and of themselves, regardless of the radiation hazard, as can thei
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Criticizing is fine. TEPCO did a total shit job, from the lack of sea walls adequate to the job, to the lack of cooling that would be adequate until generators could be restored. Vermont Yankee is another site that should be shutdown until new responsible owners are brought in. What will get you a troll mode is acting like fucking chicken little, the sky is not falling.
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Mate, give it up. Criticizing the holy nuclear industry will get the bury brigade into full motion. Fastest way to get a troll mod, even faster then posting goatse.
You got that right. It's like talking to a brick wall.
I'm amazed that some people think there will be no long term effects, or seem willing to be complicit in efforts to spin concerns away.
Perhaps a certain individual who is so certain everything is A-OK should consider investing in de-valued Japanese real estate.
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How does this, in practical terms I mean, compare to Chernobyl? Does this mean there's an area of Japan now that will not be habitable for decades/centuries? Is this area the size of a city, or more like the size of a building complex? Decades from now, are brave souls going to be wandering around a deserted area taking photos of the remains of buildings and explaining to the youngins how Fukushima became a household name?
Or is more like "yes, the numbers are bad, but it was contained." ... ?
I apologize f
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So long as it does not get worse, there will be no Zone of Alienation in Japan. There will be some buildings that probably end up entombed in concrete. Odds are the fuel will be left in them or placed in Casks. People will be allowed back to their homes in a timescale measured in months not years, decades or centuries.
If it does get worse, say there is another huge earthquake and tsunami, it could get worse. Still probably not to the level of Chernobyl, since material was not shot into the sky.
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We don't have enough data. Radioactive caesium in the soil can require wholesale decontamination because it's readily taken up by plants and makes its way into the food chain. Can. If it's all in the topsoil and you get a cloudburst, you're minus the topsoil and the problem. The newspapers aren't exactly publishing the levels of Americium or Polonium. Nor is there a vast amount of data on just how deep some of the underground contamination was and what the geology is like. If the contaminants are more likel
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I never said nothing happened. We knew it melted down shortly after the incident began. The claims I am making are that this is not the end of the world. It is not the same as Chernobyl, not even in the same league. I take it you are too young to remember but Western Europe had radioactive rain falling not too long after. Parts of Northern Europe still have high enough levels of contamination that you can't pick wild mushrooms. That does not mean that Chernobyl made all the children born after it mutants ei
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Even thyroid cancer is realistically not that bad, I say this as someone who is basically just waiting for that diagnoses. I have the precursor nodules. It is slow moving and slow growing, normally speaking. How many cases of cancer are worth not using coal? How many coal miners and asthmatics do you want to trade for each cancer death?
The reality is all of these power solutions have risk, and yes this will have a high economic cost. So does the deaths of those coal miners. Plug it into a spreadsheet and te
Re:It would be funny if it weren't so damn serious (Score:5, Interesting)
Re:It would be funny if it weren't so damn serious (Score:5, Interesting)
which may or may not be related to us growing up in on of the fallout hotspots of Chernobyl and getting a healthy dose of rain at exactly the wrong time. They all survived, but having to adjust and readjust your thyroid hormone medication all the time can be pretty shitty. Mood swings, depression, life-long dependency on medication.
I already have those issues and quite possibly for the same reason. Forget the mood swings, the adhd like symptoms or sudden weightloss are much worse. The last one is really vicious, because as you lose weight you end up with too much thyroid hormone, which leads to more weightloss, and on and on.
I agree there are alternatives, but the cost is the issue. Money really does mean the difference between life and death for many. I think 2-3 decades is being very ambitious. If we got rid of coal power on that time scale I would be ecstatic, I think we are stuck with nuclear for a hundred years or more. Solar thermal is great where it can be done. Using northern Africa to power Europe would be a great goal. It is not really an option in a place like Japan though. Not enough land to do that, and not enough light either.
Shipping enough coal or natural gas to replace nuclear power plants is expensive too. Again, that cost could well mean lives.
The new news (Score:3, Informative)
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The Germans are notoriously picky about that sort of thing. Give us the number, or compare it to the levels allowed for a French nuclear worker or a US nuclear worker. Of course livestock are being destroyed, they can no longer be sold and as such are not worth feeding. It is not still burning, and it will not make it through the concrete slab. That is why it is the last level of containment. This was a huge disaster but there is no need to act like it is the end of Japan. It still has not killed anyone, an
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So that you can get people back into their houses in a year rather than in a hundred years.
They need to cool the cores so they can permanently contain them. Hopefully they can still be dry casked, but it might not be possible anymore to move the material for a while.
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Highly radioactive fission products are in the core. They decay rapidly, creating heat. That's why it takes so damn long to cool a reactor down to the point where you can remove fuel from it. So you have to keep pumping in water until the fuel is well below 100C. If you took away the water, the reactor would heat up again.
That's also the reason that the spent fuel pool started to burn. The water evaporated and the fuel heated up to a hot enough temperature to burn the cladding, and possibly melt or b
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I heard that about Reactor 1, not 2 and 3 and from the sounds of it, they aren't sure that this was the case even for reactor 1.
Still, its possible that the earthquake cracked 1 and the tsunami screwed up 2 & 3.
Re:Cracked Vessel (Score:4, Insightful)
Maybe, if the earthquake also knocked out the cooling systems.
But it didn't, so it's likely they could have pumped enough water to keep the rods from melting at all, though they would have had a hell of a time sealing the crack.
The fact is that losing electricity to the pumps led to a cascade of catastrophic explosions turned a cracked vessel from a bad thing into a months-long nightmare. And that fact points to naive, negligent, or deliberately penurious design.
Loss of power was the big problem. (Score:5, Informative)
Mod parent up.
Some pumps were still running after the earthquake and tsunami, and they continued to run until the backup batteries ran down. Loss of power was the real cause of the disaster. If they'd some backup power source that worked, the reactors would have reached cold shutdown in a day or two, there would have been no hydrogen explosions, and no core melting.
This is really important. A plant could lose backup power for many other reasons: fire, flood, hurricanes, terrorism, contaminated fuel, tank leakage, transformer damage, maintenance outages, or exhaustion of fuel supplies. Hospitals and data centers with backup power have at times lost power for all those reasons.
Read NUREG/CR-6890, "Reevaluation of Station Blackout Risk at Nuclear Power Plants " [nrc.gov], from 2005. Volume 2, page 22, has the line "Risk is evaluated only for critical operation, not for shutdown operation. External events, such as seismic, fire, or flood, are also excluded." That, as we know now, is an overoptimistic assumption. The NRC does a statistical analysis on backup power sources, assuming independent failure of separate units, and computes the odds accordingly.
Nuclear plants that need power to reach shutdown need power sources as tough as the containment vessel. That's now very clear.
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would have reached cold shutdown in a day or two,
Really? It was my impression that even when scrammed there's enough self-reacting of a "spent" fuel rod that it takes weeks or months for the temperature to decrease to where you can remove it from a vessel, even to move to the pond to continue cooling until it's "cold". And these weren't spent rods, they were mostly in the middle of their lifecycles.
Re: (Score:2)
Really? It was my impression that even when scrammed there's enough self-reacting of a "spent" fuel rod that it takes weeks or months for the temperature to decrease to where you can remove it from a vessel, even to move to the pond to continue cooling until it's "cold".
It takes years before it reaches a state where little cooling is required. Cold shutdown, though, simply means that the reactor temperature is below the boiling point of water, the reactor vessel is at atmospheric pressure, and the fuel rods are submerged in water. In that state, a pressurized reactor can be opened at the top. The fuel rods can then be removed, one at a time, to the spent fuel pool. This is how normal refueling takes place. [nucleartourist.com]
Re: (Score:3)
It largely depends on the age of the reactor core. An older core contains more longer lived isotopes than a younger core.
That said, it doesn't take months to cool it down, even with an old core. A few weeks, tops.
Re: (Score:2)
I thought about the 'put them up high' idea, then realized that Japan gets hit with typhoons. But the basement idea was bad. Maybe a reinforced, water tight, ground level plant? I don't know, I'm not an architect.