A crack in the containment vessel of Fukashima Reactor 3 has been mentioned by MSNBC and ABC news, citing the New York Times. The New York Times has an article in which the crack is mentioned in a side bar, attributed to an anonymous person. An anonymous source is not particularly impressive, but the New York Time is. So I suppose this is somewhat impressive.
Various news sources are reporting an actual quote from the anonymous source and say a little more about him. This is what is being reported:
A senior nuclear executive who insisted on anonymity but has broad contacts in Japan said that there was a long vertical crack running down the side of the reactor vessel itself. The crack runs down below the water level in the reactor and has been leaking fluids and gases, he said.The severity of the radiation burns to the injured workers are consistent with contamination by water that had been in contact with damaged fuel rods, the executive said.
"There is a definite, definite crack in the vessel -- it's up and down and it's large," he said. "The problem with cracks is they do not get smaller." ...
In the mean time, we have this... numerous reports, from NHK and elsewhere, indicate that there is a huge spike in radiation in the sea near the reactors.
Tests done 330 meters from one of the plant's coolant water outlets showed radioactive iodine levels at 1,250 times normal, raising new concerns that one of the three hardest-struck reactors may be allowing radioactive materials to leak directly into the environment. Officials fought back against that assessment Friday. "There is no data suggesting a crack," said Nuclear and Industrial Safety Agency spokesman Hidehiko Nishiyama.
So there is a crack, for sure, and a spike of radiation that indicates that there is a breach of some kind, but there is no evidence of a crack, so there isn't a crack, for sure. Importantly, the IAEA has said nothing about a crack, to my knowledge. They are usually a day behind the news reports, but also, tend to be somewhat more accurate (but not as much as one might think).
Meanwhile, I must say I'm getting tired of hearing about how power is restored to the cooling systems of the reactors. It isn't. Every day there is a report that it is restored, or about to be restored, but so far that hasn't happened yet for the reactors that are in danger. From the IAEA:
The restoration of off-site power is still progressing and instrumentation is being tested in Units 1, 2 and 4.
So they're working on it. Meanwhile "puddles" up to 150 cm deep of highly radioactive water have been found in reactor facilities 1 and 2. Reactor facility 3, of course, has lots of highly radioactive water in it previously. Apparently, engineers are going to try to pump some of this water, mainly in the turbine buildings, into the condensers which are located in those buildings.
There is one piece of good news: For at least some of the reactors, engineers have switched form salt water to fresh water for cooling.
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From what Dynamics of Cats ( http://scienceblogs.com/catdynamics/2011/03/fuk-d_what_happened_to_the_… ) mentioned about the reactor there is only indirect evidence of a possible breach.
Basically two points, can't raise the water level in the containment vessel but that could also mean broken sensors and the amount of short lived isotopes (the iodine in the quote) but it is possible that those come from the storage pools.
The cure: Duct tape, then Gorilla tape over that.
So there may be a crack...or not.
Thanks for the insight....I will go have a glass of wine.
Or not.
Pointing out that there are conflicting reports should have a utility function, should it not, Healthphysicist? I mean, some people are only hearing one or the other!
healthphysicist, keep us posted, because we all really care.
NISA has been posting status PDFs.
http://www.nisa.meti.go.jp/english/files/en20110326-3-2.pdf
All the reactors are on freshwater now and the American barge full of a new supply arrives today.
I should start graphing out the day to day readings to see what the trend is.
Some details on the materials in the water in the turbine room of reactor no.2(from NHK broadcast):
2.9 billion Bq/cm^3
I-131, 13 million Bq/cm^3
I-134, 2.9 billion Bq/cm^3
Cs-134, 2.3 million Bq/cm^3
Cs-137, 2.3 million Bq/cm^3
Some context for those figures please? What is a yearly normal exposure? Fatal? Recommended for nuclear plant workers?
In other words should anyone be worried or not.
@Phil - That's 10 million times normal. The occupational limit for workers started at 100mSv/yr., and was raised in the course of this crisis to 250mSv/yr - but the present conditions in this area are 1,000mSv/hr.
PM Kan has ordered TEPCO to find the source of the leak. How they will do that, no one knows.
For a little more context, this is 1,000 times the very high levels of radioactivity detected in the turbine building of reactor no.3, the subject of Greg's post.
Also - radioactivity levels at no.1 have been found comparable to those at no.3 (though the composition of the fuel differs somewhat.)
Analysts at NHK are pretty comfortable talking "fission" at this point.
(And yes, in that earlier post, I did mean /yr. and /hr. - it's that bad.)
There is definitely no need to panic! There is absolutely no data suggesting the existence of a crack, at least aside from the crack itself. The heightened radiation level in the seawater could have a natural explanation, e.g. Godzilla taking a dump. It would be entirely premature to declare nuclear energy generation an 'unsafe technology' - but check back every 15 minutes or so.
Slight correction: Present levels are described as 1,000mSv/hr. because that's as high as the dosimeter could go!! TEPCO came forward to say levels "exceed the upper limit of the gauge."
"A crack in the containment vessel of Fukashima Reactor 3 has been mentioned..."
"So there is a crack, for sure...but there is no evidence of a crack..."
Love your blog Greg, and there may be a crack, but...
OK, re-read the post and can appreciate your frustration for lack of facts too. I'm in central Tokyo and a little tense. Reading enough conspiracy theories to last me a lifetime. And can someone *please* stop the "pray for Japan" meme...just send some bottled water for *&!% sake!
Phil - for the Bequerel readings:
The dose given therapeutically to kill the thyroid dead is 550MBq of I-131. You are not meant to sleep next to anyone after that treatment for weeks if not months.
The dose in the liquid in reactor 2 is 13 MBq/ml of I-131 and 2900 MBq/ml of I-134. These things are hard to work out directly as a dose to the patient, but I suspect more than a sip would be very dangerous.
For the workers there, the radiation in the water is multiples higher than in reactor 3, where the workers got very high doses and were hospitalised. Of course, they were hospitalised because they werent wearing waterproof shoes, and got radioactive stuff all over their feet ... so maybe that isnt the most reasonable context!
More concerningly I-134 has a half life of 52 minutes, so unless some other fission product is decaying into it in a big way, it may mean fission is occuring in the damaged fuel rods
Info on spike updated: http://tinyurl.com/4lrzmo8
The crack remains a mystery.
Isn't the evidence not of a crack, but of a leak. A leak could be something other than a crack. Most likely one or more pipes that are attached to the vessel, as these would be much more vulnerable to damge than the vessel itself. Hot brine can make a mess out of metal, and it has been present for several days. Supposedly with fresh water flushing, the salt content should be dropping, but it sounds like the damage has already been done. I think the only thing to do at this time, is to keep pumping water through the reactors and spent fuel pools. To the extent that the waste water can be collected and stored, it should be. Otherwise it runs into the ocean. Given the huge volume represented by the ocean, it should dilute fairly quickly there. At this point the metric of harm is going to be how much land ends up off limits. The goal at this point (aside from worker safety) should be to minimize that.
It's XKCD, but still:
http://www.xkcd.com/radiation
Omega Centauri: "Given the huge volume represented by the ocean, it should dilute fairly quickly there."
One of the favorable assumtions that seems implied in these conversations, and one that never ceases to frustrate me, is that the radioactive materials will disperse evenly though whatever medium they are introduced to.
'On average' sounds nice-- but there is no reason to think the average levels of any isotope in any quantity of water is a meaningful metric. That's just not how things mix, flow and disperse in nature. Both in the air and in water, materials move in 'plumes', remainingly suprisingly concentrated because of differences in temperature, salinity, and so forth.
An example is the Amazon river--
'The river pushes a vast plume of freshwater into the ocean. The plume is about 400 kilometres (250 mi) long and between 100 and 200 kilometres (62 and 120 mi) wide. The freshwater, being lighter, overrides the salty ocean, diluting the salinity and altering the color of the ocean surface over an area up to 1,000,000 square miles (2,600,000 km2) large. For centuries ships have reported freshwater near the Amazon's mouth yet well out of sight of land in what otherwise seemed to be the open ocean.'
(from: http://en.wikipedia.org/wiki/Amazon_River)
(see also: http://www.ouramazingplanet.com/amazon-river-plume-spied-by-satellite--…)
The mechanics of how these materials disperse in the environment will not be an average of readings taken at various locations; they will travel in plumes, and settle into areas of greater and lesser concentration (local 'hot' and 'cool' spots) Why? Becasue any time substances come into contact and mix in nature, that's how they operate. Accordingly, we can expect that the massive discharge will remain a fairly cohesive mass, traveling as a plume according to the primary currents around Japan's eastern shore:
(from: http://en.wikipedia.org/wiki/Kuroshio_Current)
"Satellite images of the Kuroshio Current illustrates how the current path meanders and forms isolated rings or eddies on the order of 100â300 km. Eddies retain their unique form for several months and have their own biological characteristics that depend on where they form. If the eddies are formed between the current and coastline of Japan, they may impinge on the continental shelf and their high kinetic energy has the effect of drawing large volumes of water off the shelf on one side of the ring, while adding water to the other side. Eddies size and strength decline with distance from major ocean currents. The amount of energy decreases from the rings associated with the major currents and down to eddies remote from those currents."
Note on the map (if you follow the link) of the southward current closer to shore, with the northward current further in the Pacific, and fairly large circular currents just east of the area that includes both Fukushima and Tokyo.
The assumption of 'dilution to harmless levels' because the Pacific is really really big, and the radioactive materials will behave nicely and spread evenly, is wishful thinking. Similarly, the idea that concentrations will diminish in an even way over greater distances presupposes that 'average dispersal rates' are of any use in the real world. They're not. Some places will find much lower levels of radioctivity, others much higher. You don't want to be in the places that are much higher, and they are going to be found much further from Daiichi than would be predicted by averaging.
OC: "At this point the metric of harm is going to be how much land ends up off limits. The goal at this point (aside from worker safety) should be to minimize that."
Omega, with all due respect, the metric of harm remains what it always has been-- how many people become seriously ill, how many suffer and die, how many children are born with birth defects, and how many people's lives are simply destroyed because they can never return home. There's an abstraction in talking about 'land off limits' that borders on callousness.
How many people would you estimate-- as we see things today-- are going to die because of the radiactive material already introduced into the environment? If you claim just a few of the workers at the plant, you're simply not acknowledging what's been happening.
Omega, the evidence for the crack, and the only evidence for a crack that I know of, as stated in the OP, is some guy who reportedly said "I saw this big crack" and described it somewhat.
I may well be that the final net harm other than injury to the plant workers will be land set off limits for a period of time, plus a zillion dollars in cleanup costs.
These things are built in layers and I doubt the witness stuck his head inside the reactor chamber to view the inner containment vessel. An outside crack may or not continue on as an inside crack. They need to get the instrumentation working fully to know for sure.
OK, I just got this from the German news which means it has probably been translated times already, so could someone with more information please either confirm this nonsense for me, or tell me what they said or probably meant? According to the tagesschau, Edano said that the Japanese Government assumes there might have been a partial meltdown (OK, so far I get it), but that they also think that this is only temporarily.
That last part leaves me clueless. Do they think the meltdown has stopped? Because even I know that there cannot be an "unmeltdown"
Giliell @ #22:
It's really just supposed to sound mollifying - technically, any meltdown is 'temporary': the fission will only continue until all of the available fuel is used up. They suspect that the meltdown is only partial, i.e. that only part of the fuel in the reactor is affected (either because the rods have partially lost their cladding, or parts of the fuel rods have broke off and collected at the bottom of the containment vessel), so fission will cease once that amount of fuel is spent - but since there seems to no idea what amount were actually talking about, it's really more or less a complete non-statement.