Jorge Stolfi said:I watched a documentary on Chernobyl the other day. One lesson that Japan could have learned from that incident is: do not let the the plant operators remain in charge of disaster contol. At Chernobyl, precious days were lost while the operators (and their bosses and bosses' bosses, up to cabinet level) insisted that "everything was under control". Real action began only after Gorbachev pushed those people aside and put a committee of the country's top nuclear scientists in charge.
Unfortunately it seems much harder to do that in Japan, given the constraints of capitalism (Fukushima-I is still the private property of TEPCO) and the fact that the State is in many ways subordinated to big corporations like TEPCO, GE, Toshiba, etc. So here we are, 1000 hours after the accident and we are still wondering whether there is any real cook in the kitchen.
The lack of management's understanding of the working environment at the plant could lead to a blunder or a delay in the work.
April 21, 2011
http://mdn.mainichi.jp/perspectives/news/20110421p2a00m0na001000c.html
Michio Ishikawa, a top advisor to the Japan Nuclear Technology Institute : "I think TEPCO also needs to review its organization, for example, by having someone who can exert strong leadership [to spearhead the timetable's implementation]."
April 19, 2011
http://www.yomiuri.co.jp/dy/national/T110418004891.htm
TEPCO's roadmap only mentions equipment at the plant. However, it is human resources that will place the plant under control. Therefore, measures to extend support for workers should be incorporated in the roadmap.
The operator of the troubled Fukushima Daiichi nuclear power plant is to cut annual salaries of its workers by around 20 percent as part of efforts to fund compensation payments over the nuclear accident.
Samy24 said:"to feed the dog with something" that is how the public is feeling about the information "policy" of TEPCO.
But why are they doing so?
To hide the real size of the disaster? -> It's INES 7 already.
To secure "engineering secrets"? -> I do not belief the Iran like to copy this crap.
TEPCO itself do not have more data, pictures and information? -> God forbid.
The Kan administration feared that Japan would be abandoned by the rest of the world, and hoped the helicopter mission would help the country overcome the negative images.
"The release of water was a display to the U.S. We were showing them how serious Japan was," a high-ranking Japanese government official commented.
http://mdn.mainichi.jp/mdnnews/news/20110422p2a00m0na005000c.html
no more than 1 mSv in 5 hours in the 20 kms zone? Uhhhh, are they basing this procedure onto some radiation data that they have to declare this? This would be 200 microSv/h exposition, which is quite huge...The government will only allow the evacuees to be at their homes for up to two hours in order to minimize their exposure to radiation. "We wanted to make sure that residents will not be exposed to more than 1 millisievert of radiation even if they spend five hours, including travel time, in the 20-kilometer zone," said an official with the Nuclear and Industrial Safety Agency.
The text has been corrected.AntonL said:Has the freshwater supply at Fukushima dried up? Or has SFP 1,3 & 4 always been replenished with seawater.
http://www.tepco.co.jp/en/press/corp-com/release/11042203-e.html"
Previous reports just stated water spraying
On March 25 and 26 reactor cooling was switched from sea water to freshwater.
Unit 2 SFP was regularly filled with fresh water according to Tepco reports. Unit 1, 3 and 4 SFP replenishing is always referred to as water spraying with concrete truck.
Finally, the oceanic currents computed by our model are not the reality: they are the result of mathematical equations too simple to fully represent the complexity of nature. The wind which strongly drives the oceanic currents is also a forecast whose accuracy is not known.
We do not know how much radionuclides have been injected, when they have been injected and how they behave once they reach the sea. That is why we do not claim that our simulations are able to provide an accurate quantification of radioactivity in the sea. However, in order to build our scenarios, special attention has been paid to the measurements of Cesium 137 concentration taken several times every day by TEPCO at 30 and 300m in front of the nuclear plant.
Two sources of radionuclides are considered. One corresponds to a direct emission in the sea in front of the nuclear plant (migration of water contaminated by the reactors), the other one corresponds to fallout of atmospheric particles. In the first case, we introduce a flux at the grid point corresponding to the nuclear plant. This flux is adjusted to produce a concentration close to the values of Cesium 137 measured (see our page of validation). In the last case, we have assumed that the deposition from the atmosphere takes place in a circle of 200km of radius with a concentration maximum at the centre of the circle positioned at the nuclear plant and decreasing with distance. The flux corresponds very roughly to preliminary estimations given by atmospheric model. We intend to improve these values in a next future as results of atmospheric model are available.
For each source (direct release and atmospheric), we consider two cases: one corresponds to dissolved elements, the other one to particles that fall into the sea with a velocity of 10meters per day. Obviously dispersion in the first case will happen at larger scale than for the second case for which deposition of particles on the sea floor reduces the dispersion.
They've been offered nuclear accident robots and other equipment for free by KHG and INTRA . I bet they were also offered crews, but opted not to have any non-TEPCO personnel doing measurements on site. They could get anything they ask for. The losses to nuclear companies from this accident must be incredible. AREVA is offering to do anything possible. Every nuclear company's money are at stake, everyone got strong financial incentive to help. For some reason, it still appears as if only TEPCO employees are doing any measurements.tsutsuji said:I wonder if the robot missions are more than a show to please the United States, in a fashion similar to the helicopter drops :
"The Kan administration feared that Japan would be abandoned by the rest of the world, and hoped the helicopter mission would help the country overcome the negative images."
Yes, the thing is that evacuation itself carries risks so there should be a threshold for evacuation. Some threats you can't run away from. Suppose some immense radiological disaster results in 0.1% higher risk of cancer in an area of population ten millions. That is 10 000 dead. But evacuating such population, with associated spike in disease, may kill more. There's nearly nothing you can do about 0.1% excess risk. You can't even measure it directly, only estimate from theoretical considerations (e.g. role of mutations in cancer) so you can't even 'prove' it in the legal sense.jlduh said:Finally, japanese government starts to move from its original position about evacuation zone and expands it north-west, as we were talking about yesterday on this thread !
http://www3.nhk.or.jp/daily/english/22_20.html
So is this 20 mSv a "threshold" or a "safe limit"?
(a lit bit of irony inside, i admit ;o))
I think it is now accepted by many specialists that any increase of artificial radiation is also an increase in diseases risks, like it is also with many chemical products that act on health of living organisms WITHOUT ANY THRESHOLD MECANISM. This is called "excess risk" and "relative excess risk":
http://cat.inist.fr/?aModele=afficheN&cpsidt=1886907
http://www.rerf.or.jp/radefx/late_e/cancrisk.html
So in fact you were right and i was wrong: there is probably no "safe limit" for radiation, there is only a threshold for evacuation decision...
Japanese government officials and relief agencies hadn’t asked for the robots, but the company saw no reason to wait for a request.
...
The company wasn’t asked to send its robots to New York City after the terrorist attacks of Sept. 11, 2001, but it did.
March 26, 2011
Helping hand from iRobot
Bedford firm sends four robots to Japan’s rescue, recovery effort
http://articles.boston.com/2011-03-26/news/29352816_1_irobot-military-robots-packbots
there's not only robots that were missing. KHG also has portable isotope analysis equipment, which can and IMO has to be used to recognize criticality, if it happens, as soon as possible.tsutsuji said:Also the irobots were not initially requested either by Tepco or by the Japanese governement :
I wonder if the irobots were chosen (among the other Areva, KHG, and Japanese robots) because they best fitted the planned mission or because that US company insisted so much that Tepco finally gave in.
Dmytry said:there's not only robots that were missing. KHG also has portable isotope analysis equipment, which can and IMO has to be used to recognize criticality, if it happens, as soon as possible.
What REALLY bothers me btw is the attitude that you have to theoretically prove that criticality happened before you start doing measurements to see if it happened / may resume. That it is seen as normal they aren't testing for short living isotopes. (they used to, and there was Cl-38 and I-134 figures, if you remember, in that radioactive water from reactor 2. Then the officials said 'it is hard to imagine re-criticality in shut down reactor', never mind that after it was dry for hours, it is not a reactor any more but a mess, almost geology. Back in the day when natural uranium was 3% U-235, there were natural nuclear reactors. This stuff is up to 5%)ascot317 said:Getting KHG or something similar in there would have been my first task.
Instead, PackBots, T-Hawk and "Technicians" who can't even work with counters.
It's freaking me out, Japan isn't some 3rd world country, isn't it?
Dmytry said:What REALLY bothers me btw is the attitude that you have to theoretically prove that criticality happened before you start doing measurements to see if it happened / may resume. That it is seen as normal they aren't testing for short living isotopes. (they used to, and there was Cl-38 and I-134 figures, if you remember, in that radioactive water from reactor 2. Then the officials said 'it is hard to imagine re-criticality in shut down reactor', never mind that after it was dry for hours, it is not a reactor any more but a mess, almost geology. Back in the day when natural uranium was 3% U-235, there were natural nuclear reactors. This stuff is up to 5%)
I don't believe I have ever read "the paper" (oft cited: W. Russell, Oak Ridge National Laboratory) either. My internet search skills may be deficient, I suppose, else there was no single "paper" on the subject.|Fred said:It would have be a equally failing understanding. It is not a safe limit it is the threshold that we do not want to exceed for artificial if possible.
Nope, this map is for dose induce by radioactive matériel from Fukushima, it take into account decay, external ionization and internal inhaled particule. it assume one is standing outside 247. and does not take into account that radiation exposition would be mitigated by the time you spend indoor (as requested).
As for the 1 mSv you get it from the ²²²Rn present in the air every one breath .. You also get 0,2mSk from your own potassium etc ..
http://www.rchoetzlein.com/theory/wp-content/uploads/2011/03/radiation.jpg Here again this is a miss understanding, on the "no risk concept". Of course there is a risk, every time you take some medication there is a risk, I almost die the first time I toke penicillin, every time you do something there is a risk.. There is no such thing as risk free, But what is commonly admitted is that when the probability of something bad to hapen is low enough or lower that a lot of other thing we consider it risk free. Call in un "abut de language" or convention..
I mentioned different annual dose for different country France + Dose from this map < annual dose from the states or Sweden..
As low as possible is the word, unless you are Tcup's mice ( I have yet to read the paper), now if you do a proper assessment you have to take into account other choice you make and pose superior threat.
You still don't get, or refuse to ... Let's have an other go.jlduh said:..
Yes you are correct. Hydrogen peroxide has to decompose or come into contact with an organic substance. Hydrogen peroxide on a rag can heat and spontaneously combust. My point is that you don't need any source of ignition and it will decompose rapidly at 70 degrees Celsius. If my research is accurate.Borek said:Hydrogen peroxide is not combustible.
speaking of combustible stuff, what's about boral plates, can someone comment on that? Aluminium powder, and the bloody things are not even watertight, they swell from hydrogen accumulation and the "solution" was to clip corners so that hydrogen could escape (never mind more water getting in).M. Bachmeier said:Yes you are correct. Hydrogen peroxide has to decompose or come into contact with an organic substance. Hydrogen peroxide on a rag can heat and spontaneously combust. My point is that you don't need any source of ignition and it will decompose rapidly at 70 degrees Celsius. If my research is accurate.
what irks me about mox (or even just the old fuel) is that some sort of fractional distillation, or gradual crystallization of molten core, or something of this sort, could result in locally higher concentration of plutonium. It's very different in that respect from u235/u238. It seems to me that it would be very difficult to rule out such a possibility, when you mix salt, water, zirconium, uranium dioxide, plutonium dioxide, etc. and cook it at high temperatures, gradually raising and then lowering the temperature, very slowly.Krikkosnack said:Other bits of information..MELCOR Best Practices - An Accident Sequence Walkthrough L. Humphries
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http://www.ncnr.nist.gov/trtr2005/Proceedings/Belpomo - Phebus presentation.pdfhttp://www.ornl.gov/~webworks/cpr/v823/rpt/109264.pdf"
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source http://forum.atominfo.ru/index.php?showtopic=575&st=520
Dmytry said:re: LNT.
Well, for example camels have a threshold for load on their backs, and the dose response of a camel to load on the back is very complicated, however, when they are loaded with a load of gold that kills 20% of camels and maims another 20%, rest assured, effect of extra straws can be expected to be linear even though straws are very different from gold. Ditto for humans really.
There may well be a weight lifting program for a camel that would dramatically decrease camel's risk of suffering broken back, but haphazardly adding random numbers of straws to already 20% dying camels ain't going to be good, and effect oin the population can be expected to be linear (approximating tiny piece of response curve with a line).
We humans have high mutation load, high enough for 40% cancer rate. Single cell studies have indicated that single particle track through nucleus of single cell sometimes results in mutation. In my book, that is theoretical basis enough to require LNT for safety.
It may not be the basis enough if 'radiation' was a human on trial for murder and innocent until proven guilty applied. Then you'd have real trouble convincing jury for unanimous vote. You could perhaps even pull the trick with genetically engineered mouse to set your client free. But for safety, too many people have died already from 'safe until proven unsafe' approach (google for 'radium dial painters' for example, google for the 'radium medicine', etc).
Dmytry said:what irks me about mox (or even just the old fuel) is that some sort of fractional distillation, or gradual crystallization of molten core, or something of this sort, could result in locally higher concentration of plutonium. It's very different in that respect from u235/u238. It seems to me that it would be very difficult to rule out such a possibility, when you mix salt, water, zirconium, uranium dioxide, plutonium dioxide, etc. and cook it at high temperatures, gradually raising and then lowering the temperature, very slowly.
jlduh said:new data from Tepco website on underground water contamination:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110419e11.pdf
and pdf with time curves for all reactors samples:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110419e12.pdf
jlduh said:Well, maybe i should have written maximal ALLOWED dose for general population (defined by french safety coden but that is the limit in many countries for artificial radiation). Which i expect is a "safe limit" by the way ;o)
etudiant said:It seems that this accident is gradually worsening, with no coherent strategy to resolve it.
The public parameters certainly show deterioration, with the closing of the immediate 20km zone and the extension of the contaminated zone to the north.
Also, while the official charts summarized here: http://fleep.com/earthquake/ show a reassuring steady decay of the measured contamination, the level privately monitored here http://www.ustream.tv/channel/%E6%94%BE%E5%B0%84%E7%B7%9A%E3%83%AC%E3%83%99%E3%83%AB from Chiba has about tripled since the April 19-21 inland wind and rain, to about 30 microsieverts/hr.
It does seem that the analogy to the frog being slowly boiled is not entirely off the mark.
Must a larger part of Japan become uninhabitable before the Japanese leadership recognizes that the current approach is not working?
etudiant said:...
etudiant said:It seems that this accident is gradually worsening, with no coherent strategy to resolve it.
The public parameters certainly show deterioration, with the closing of the immediate 20km zone and the extension of the contaminated zone to the north.
Also, while the official charts summarized here: http://fleep.com/earthquake/ show a reassuring steady decay of the measured contamination, the level privately monitored here http://www.ustream.tv/channel/%E6%94%BE%E5%B0%84%E7%B7%9A%E3%83%AC%E3%83%99%E3%83%AB from Chiba has about tripled since the April 19-21 inland wind and rain, to about 30 microsieverts/hr.
It does seem that the analogy to the frog being slowly boiled is not entirely off the mark.
Must a larger part of Japan become uninhabitable before the Japanese leadership recognizes that the current approach is not working?