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Safety Measures Fail To Stop Fukushima Plant Leaks
AmiMoJo writes "The operator of the Fukushima Daiichi plant has been developing countermeasures to deal with repeated leaks from tanks of contaminated water. But despite the measures, 100 tons of radioactive water leaked on Wednesday and Thursday. 'The leaked water was among the most severely contaminated that Tepco has reported in the aftermath of the March 2011 disaster at the Fukushima Daiichi plant, when damage caused by an earthquake and a tsunami led to meltdowns in three of the plant’s reactors. Each liter of the water contained, on average, 230 million becquerels of particles giving off beta radiation, the company said. About half of the particles were likely to be strontium 90, which is readily taken up by the human body in the same way that calcium is, and can cause bone cancer and leukemia.' The estimated volume of the leaked radioactive materials caused Japan's nuclear regulator to rank the leak a level-3 serious accident. The international scale of nuclear and radiological events ranges from zero to 7."
Indeed, the total spill is about the same size as a large-ish residential pool. The ocean will never know.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
It's not like everyone hasn't been saying this for 3 years now. If you'd been paying attention, you would already know this was the case. But I remember when people were saying this in 2011, 2012, even into 2013, they were nay-sayed and called coal shills and alarmists. Now what?
I'm no nuclear engineer, but it seems to me that IF (big if) It were as simple as letting the fuel melt through the floor like a big ol' glowin' gopher, you'd have a hell of a time containing the vapor emitted.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
Once the melted core hit the water table (considerably shallower than 1000' down considering the proximity to the ocean), you would get a huge radioactive steam geyser throwing the fission products into the atmosphere.
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Becquerels of particles? Really? That's like saying (obligatory car analogy incoming) joules of cars. A becquerel is a measure of activity - each litre gives off 2.3e8 electrons per second. While this is a problem, this is a nonsensical way to talk about it. What's that law again? The one that says that "every news article in your field of expertise is utter garbage". I'm pretty sure it holds here.
Cynical Idealist
Ummm, Physics would happen? Unless you had a convenient hole to pool the melt in it will just spread out and solidify ( that what the "core catcher" dishes under the reactors are designed to do ) and stop "reacting" so you would not get the melt actually burning a hole in the ground, you just have a spread out highly radioactive glassy metallic mess sitting at hot temps because of the residual decay heat.
That and ground water, if the melt would burn down it's going to heat up water in the ground, resulting in radio-steam blasting from the hole, probable widening of the fractures the water is flowing through leading to ground instabilities, and irradiating of your groundwater supply.
As others have stated as well, anything the hot melt would burn would also be irradiated and sent to the atmosphere, as well as radio-decay gasses.
In other words, it would be a much more horrible headache than trying to control the decay heat until the fuel can be decanted and put into a longer term storage.
To err is human; effective mayhem requires the root password!
The would give you a nice fire that would carry a significant fraction of the nuclear material in fine-dust form quite far. As in making Japan inhabitable with wind in the wrong direction. This type of fire was what spread the Cernobyl nuclear material all over Europe. Of course that was a bit less than what they try to contain at Fuckupshima.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
"massive radio active steam and dust cloud and the resulting fires and highly molten core would create radio active dust high into the atmosphere that would spread for thousands of miles"
you mean like current coal plants do?
"Though the concentrations are low, the total amount of TENORM in fly ash is noteworthy (Beck
et al. 1980; Beck 1989). For example, in 2004, U.S. electric power plants burned approximately
921 million MTs of coal (U.S. DOE/EIA 2005d). If that amount of coal is burned with 1.5 ppm
uranium, 1,381 MTs of uranium would be concentrated, in addition to other TENORM quantities."
[http://www.epa.gov/rpdweb00/docs/tenorm/402-r-08-005-voli/402-r-08-005-v1.pdf] - EPA
They cannot. They are having serious trouble finding people to work there as it is. Don't forget that these workers risk infertility, malformed offspring and worse.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
"Google Cherynobyl? To this very day it is so radioactive you can't get within 50 to 100 miles of it?"
After the accident/explosion/fire etc. in 1986 the Ukrainian authorities continued to operate the three other undamaged reactors at Chernobyl (they needed the electricity supplies). After a few years folks started running tourist trips to visit the area including the evacuated towns surrounding the damaged reactor. Thousands of workers have been working on the reactor building for decades attempting to entomb it or at least cover it up so it doesn't leak quite as much residual radioactivity as it does even today.
Sure in a Hollywood disaster movie script the Chernobyl site is so radioactive you can't get within 50 to 100 miles of it. However this is real life which is kinda different.
Ah, I just realised you're trolling, aren't you? Silly me.
Love that comic. Bloom County was amazing and I miss it daily. Seen that particular one many times and had no interest in copying it from that website (I already own at least one book that includes it) until I tried to run my cursor over it. I just wanted to read it and kind of use my mouse cursor sometimes like a person would their fingertip to follow the text. The moment I did that the big red COPYNO.com image replaced what I was trying to read and it became my mission in life to copy the damned picture. Out comes my screenshot utility and moments later I'm sending that out to several people just because I can.
Appended to the end of comments you post. 120 chars.
Except that much like mercury the radioactive material is biologically concentrated. I've heard the US has already drastically (20x?) raised its "safe threshold" levels for radioactive materials in foodstuffs to allow Pacific fisherman to continue to sell their catch.
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Unless you take a guided tour.
However, this demonstrates nicely the factual level anti-nuclear lobby operates at.
Forget magic. Any technology distinguishable from divine power is insufficiently advanced.
This depends on how much mass there is, whether it's concentrated in a small lump, or flows through the paths of least resistance, and separates, and spreads out, (like chernobyl did). If it spreads out, the reaction slows, and then, it's largely decay-heat that's left over (which is pretty significant, but still, not 3000 degrees C significant).
Youtube is full of videos of steam-clouds that have been around the plant since roughly June 2012. This *seems* to indicate that there's something hot contacting moisture in the ground, and forcing out steam over an area of soil, but it's not consistent with a 77-ton mass of molten material dropping into a lake (ie. worst-case steam-explosion situation which is often portrayed as the result of a meltdown). The plant is along the coast, so fog has never been an unusual occurrence, so that likely conceals the fact that the core is issuing radioactive steam through cracks in the soil. A simple sampling and test of the steam should reveal if this were the case. But we're not getting that kind of data from Tepco.
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Well, dilution *is* a reasonable approach to disposing of this waste, but what we have here appears to be an ongoing leak from a point source into tidal waters, which is not at all the way you'd design a project to dilute the waste.
There are several big differences between letting the stuff leak and a proper attempt to diffuse the waste over a large area of the ocean. First of all the leak is a point source discharging into an intertidal zone. My wife is a physical oceanographer who helped site a major sewage outfall, so I remember some of the concerns. Stuff that is discharged right near the shore doesn't diffuse nicely out to deep water, it gets transported along the shore with the same currents that deposit sand from rivers along the coast.
This means that the S90 may well get deposited in sediments. The concentration of S90 probably won't be enough to be a direct concern to humans, but because strontium is an analog to calcium, it can bioaccumulate. This means the somewhat incomplete process of dilution gets undone when critters like benthic worms on the bottom of the food chain consume the S90, and are in turn consumed by ground fish and so on up the food chain. At each trophic level the S90 is concentrated a little more.
I agree that the amount here reported is probably not a serious threat to human and environmental health, but the problem is that this process is ongoing. It is possible that what is going on doesn't present any threat to human or environmental health, but we can't be sure. By the time we figure it out it will be too late to do anything (or anything affordable) about it if it is a problem.
In a nutshell: dilution could work, but there's a significant chance that just letting the stuff leak into the sea won't do the job. This stuff needs to be contained or otherwise dealt with *now*.
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why not just let the thing meltdown? It would essentially bury the fuel. After it drops down a 1000' or so, fill the hole in with cement. I wouldn't be too worried about volcanic eruptions, radiation is what keeps the earth core nice and soft.
The most important reason is that 'corium' isn't actually hot enough to burn through the earth like that, nor does it conduct heat all that well, even if any part of it became hot enough.
The integrity of the fuel rods is challenged at 2200F (zircaloy-water reaction, which released the hydrogen that caused the reactor building roofs to blow off on three of the Daichi units.)
Steel melts at about 2600F. Concrete breaks down at about 1800F.
In addition, the fuel is a uranium-oxide mix, a sort of ceramic. This class of material is generally known for poor thermal conductivity. That's why the pellets are the size of a pencil eraser, they need to be small and have a high surface area in order to conduct heat from the center of the pellet- which might be at 3000F in normal operations- to the fuel cladding and into the reactor coolant, which might be around 600F.
Anyway, from what I know about western reactors (it's my line of work, but i'm not a reactor engineer per se), I seriously doubt the fuel would 'burn' through steel or concrete. The fission products escape because of physical destruction to the facility caused by the Tsunami, or because of relief valves that limit reactor coolant system pressure, or primary containment structure pressure.
Chernobyl's release was due to a massive overpressure event that physically broke the reactor vessel. Nothing ever burned through concrete (check out the photos of the 'elephant's foot')
Three Mile Island's core was found in the bottom of the reactor vessel; a small amount of fission products was released by mis-operation of support systems. The integrity of the reactor vessel was never threatened, though the containment building (much larger than Daichi primary containment structures) withstood several hydrogen burns.
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Strontium 90 has a half-life of 29 years. Obviously the process of decay will go on indefinitely, so it's pretty much meaningless to say that the leaking isotopes will decay "in decades".
What we need to know is how long will it take the concentrations of harmful isotopes to drop to acceptable levels. Thata of course depends on how many times greater the concentration is than acceptable levels.
If the initial concentration of S90 is acceptable, the answer is "instantaneously". If the concentration is 4x acceptable, the answer is "116 years". So it's not inconceivable that an S90 contamination problem could persist for centuries, although we have yet to determine whether we have such a problem.
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If you're not part of the solution you're part of the precipitate.
No brain, no pain.
Strontium 90 has a half-life of 30 years, genius. So if for example it's 100 times natural now, it will decay to 50x in 30 years, 25x in 60 years, 13x in 90 years, 6x in 120 years, 3x in 150 years, 1.6x in 180 years.
Cesium 137 has the same half-life: 30 years.
I suppose 180 years is "decades". Just as much as it is also "centuries".
Hell, a million years is 100,000 "decades".
Fukushima is a serious nuclear disaster. It's a very situation that we should all be concerned about. But this should not lead to any pause in our appetite for nuclear energy.
What people often fail to appreciate is that even coal fired powerstations release quite large amounts of radioactive material in to atmosphere. Coal fired powerstations burn about a million times as much material as a nuclear powerstation per joule of energy produced. Some of that material is radioactive. That stuff isn't been sealed in a container in burrried in a mountain, it's being blown up chimney stacks along with the rest of the rather unpleasant stuff.
Don't believe me? Reflect on this passage taken from this (PDF) document:
So far, there has not been a single confirmed death due to Fukushima accident. In comparison, there were 20 deaths in the US just mining for coal in 2013. This is not to mention all the deaths being caused by cancers and other health problems being caused by breathing polluted air.
If we're ever going to get on top of this climate change challenge, nuclear must be leading the charge. Nuclear is a safe, non-polluting technology. Modern designs are fail-safe in every sense of the word. The newer designs can even cope with a loss of external power (like Fukushima experienced) yet still stay safe.
This is the 21st century. The technology is mature, sensible and safe. Really, we should be looking to retire every coal fired plant as a matter of urgency, if only to reduce the amount of radioactive contamination of the atmosphere!!
I didn't think you were trying to be an apologist. I agree this situation is not an issue for global, regional, or even local panic.
There's a lot of ground between "not a serious problem at all" and "everybody run for the hills", and this situation falls into that territory.
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TEPCO still doesn't have adequate water-processing capacity Fukushima. They installed three units of the "advanced liquid processing system" (which is basically a big ion-exchange resin water purifier) in 2012, and they are still not working reliably. Failures are occuring for dumb reasons: "TEPCO officials believe the cause of that problem was due to a failure to remove a rubber pad from the tank, leading to a blockage in the system." On another occasion, they had to shut down because a crane failed.
Toshiba has overall charge of the project. Why a major Japanese company is having so much trouble with routine industrial tasks is not clear. As a result of all these processing problems, Fukushima has far too much contaminated water in temporary storage.
The process won't remove tritium, but that, at least, has a decay life of only 12 years, and it's not concentrated by biological processes like strontium and cesium, so dumping tritum-contaminated water isn't too bad.)
Nonsense, the concentration in the pacific is negligible and not a danger. you have no understanding of units of meaure of radioactive contamination. You read alarmist nonsense without sense of proportion or scale.
The area around Fukushima that is considered of any possible danger to humans is quite small, measured in low double digits of kilometers
there is no significant CS-137 contamination even ten miles from Fukushima. Not a danger to humans, and the levels now are less than 1/10,000 from when the disaster happened.
It does not improve my comfort with nuclear power that these people are still in charge of this plant.
Help stamp out iliturcy.
Chernobyl reactor design and failure mode and fire of no relevance to Fukushima issues or this discussion
100 tons of water is 24,000 gallons, or about 3600 cubic feet of water.
That's roughly about the same amount as two (2) of the large tanker trucks that fill up a gas station.
Or, in Olympic Pool metrics, about 1/24th of a Pool.
In radiation terms, 230m Bq per liter (for 24,000 Gal = 91,000 L) or 21 Trillion Bq.
A single (average) coal plant puts out about 4 Quadrillion Bq via emissions pollution. So this spill is roughly 0.5% of the yearly output of a coal plant (or, 46 hours of operation of one).
In terms Banana Equivalent Dosage, you're talking about 1.4 Trillion bananas per hour to start with, halving every hour.
And Now You Know.
-Erik
There are always four sides to every story: your side, their side, the truth, and what really happened.
Good catch. The claims are widely circulated, but doing my own googling shows conflicting reports from the sources I'd actually consider halfway reliable for such information. If I ate enough fish to actually care I'd investigate further. For now I think I'll just shut up.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
'Corium' is basically molten ceramic (The fuel is a uranium-oxide matrix.) It has such poor heat conducting properties that during normal operations, it could be 3000F in the center of a pellet, and 650F on the surface of the cladding- 3/16" away from the center.
Alcohol, Tobacco and Firearms should be the name of a store, not a government agency.
That's 380 million per liter times 100,000 liters. Considering how much of this stuff they have on the site the total must be quite horrific.
Help stamp out iliturcy.
A single (average) coal plant puts out about 4 Quadrillion Bq via emissions pollution. So this spill is roughly 0.5% of the yearly output of a coal plant (or, 46 hours of operation of one).
In terms Banana Equivalent Dosage, you're talking about 1.4 Trillion bananas per hour to start with, halving every hour.
You are not comparing like with like. The potassium in a banana is mostly passed through the body harmlessly, as only enough to maintain the normal level is absorbed. The strontium in this water is absorbed by the body like calcium, accumulating in the bones where it will sit for years or decades slowly irradiating you, which is why is causes cancer and leukaemia.
Similarly the output from coal plants is not nearly as dangerous as the content of this water.
I'm disappointed. I expect more than this level of scientific illiteracy from +4 Slashdot comments. The Banana Equivalent Dosage is about as credible as the claim that bananas prove intelligent design, and yet it keeps getting repeated here as if it were a convincing argument.
const int one = 65536; (Silvermoon, Texture.cs)
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You are not comparing like with like. The potassium in a banana is mostly passed through the body harmlessly, as only enough to maintain the normal level is absorbed.
Mostly correct. Instead of only absorbing "only enough to maintain the normal level", what you will actually get is absorption of a bit more than enough to maintain the normal level, coupled with increased elimination (mostly via urine) to maintain that normal level. Either way there is no difference -- there is no long-term storage of Potassium in the body, it is all present as the soluble, highly-mobile aqueous ion. So any increased level of from a radioactive source will relatively rapidly come back down to equilibrium levels of radioactivity, once you return to your intake from your regular Potassium sources.
Anyway, the ratio of radioactive Potassium (to non-radioactive Potassium) in your body will be equal to the average level of radioactive Potassium in Bananas (and other dietary sources, mostly plant-derived materials); the Potassium-40 isotope to non-radioactive isotopes is mostly at equilibrium concentration in the environment. For a 70kg human this means approximately 160g of total Potassium in the body, with 0.0187 grams of 40K, producing 4,900 disintegrations per second (becquerels).
The strontium in this water is absorbed by the body like calcium, accumulating in the bones where it will sit for years or decades slowly irradiating you, which is why is causes cancer and leukaemia.
Partially correct. Like Potassium, Calcium is regulated at a "normal" level, and the body will reduce absorption (from the gut), and increase elimination (mostly through urine) to eliminate excess. Accumulation happens if there is a deficit, or with active deposition of osseous material. However, due to constant turn-over of bone Calcium, at any given time a small amount of material is simultaneously being both absorbed and released from long-term storage. So this means a small amount of the ingested material will go into long-term storage, even when your body is not actively increasing Calcium stores.
However, note that while Potassium-40 and non-radioactive Potassium are chemically identical (well, almost identical -- some tiny kinetic effects may be present, negligible), Calcium and Strontium are not. They are grossly handled the same by the body, but there may be some differences in absorption / retention / excretion rates between the two substances -- so the radioactive Strontium will not be a straightforward constant fraction of the Calcium pool as it moves around in the body.
I'm disappointed. I expect more than this level of scientific illiteracy from +4 Slashdot comments.
I'm not disappointed; I never had any expectations to begin with :)