Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[rowmag]

*Ponder*
[PLAIN]http://img850.imageshack.us/img850/2685/unit4preexplosionhole.jpg[/QUOTE]

Hmm, yes, if it is a door or hole, it doesn't really match the post-blast structure very well, does it...

Now the middle, low-res image is looking to me like some object that is standing there on the roof in front of the wall. I can imagine I see two posts, joined by a thick cross-piece at the top, and they are casting a shadow on the wall.

Something shaped like this:

====
|  |
|  |

Maybe something like a small-ish wheeled crane?

(And it would be up there because...why?)

And where might it have gone after the blast? No sign of it under the rubble on the roof, but perhaps it got blown down with the staircase and is on the ground near the corner of the building? (The video taken from the top of the Putzmeister shows some wreckage down there, but it is unidentifiable.)

 

[AntonL]

Here is a very interesting, comprehensive and very damming report on the AREVA water treatment

http://blogs.forbes.com/jeffmcmahon...s-radioactive-water-detailed-including-risks/

 

[rowmag]

As a follow-up, I wrote:

The PDF file is specifically a report on the condition of the long-term stored MOX at Unit 3, but that doesn't exclude the possibility that plastic covering is standard procedure regardless of the fuel. Have so far just skimmed the file, though.

Searching through the file finds no other reference to the plastic covering, but some references to fiberscope searches for foreign matter in the assemblies (not much found), but no particular reason given why this should be a MOX-specific issue (to go to NUCENG's query). So perhaps such plastic covering may have been used in SFP4 as well?

 

[artax]

Interesting video here, nut I don't know geographiacally where from?



Oh there's a map a few minutes in.

And a map of contamination around site here.

http://www.youtube.com/watch?v=Yn5UpvoIbzYhttp://www.youtube.com/watch?v=Yn5UpvoIbzY

 

[fluutekies]

triumph61 this is a nice find, here we have all the published data tabulated in a spreadsheet thanks to the hard work of Masato Fujii http://twitter.com/toofuya

Browsing this data, I possibly discovered a unpublished problem for reactors 5 and 6.

Plot of water level and water temperature of reactor 6
[PLAIN]http://k.min.us/iliXFo.JPG
left axis reactor temp, right axis water level above reactor fuel, blue is for water, red-brown is for temperature
From this plot we can draw two conclusion
1) Reactor 6 water seems to be slowly leaking, either into the primary containment or to the outside (classic saw-tooth plot), and since cooling was re-established water has been replenished on three occasions. (or is there another explanation)
2) Reactor 6 cooling is a start stop operation

Assuming reactor diameter of 6 metres, then 1 metre change in level is 113 tonnes of water, thus the leak rate is about 50 to 70 tonnes a week

Also, from the spreadsheet data similar situation exists in reactor 5


One can see the effect of the water temperature rising as small peaks in the water level.

Same strange saw tooth pattern in dry well #6 for dose rate.
http://atmc.jp/plant/rad/?n=6

 

[Rive]

Interesting video here, nut I don't know geographiacally where from?

Cesium works like that. It forms local 'hot' spots on and lines on surfaces around water flows.

 

[AntonL]

(I apologise should this been posted earlier)

http://www.asahi.com/english/TKY201104240109.html

Recognized as the world leader in robotic technology, Japan will finally deploy its own robot at the crippled Fukushima No. 1 nuclear power plant after relying on US-made versions to do all the work.

...

Another project to develop a robot for a nuclear accident started after a fatal accident at JCO Co. In Ibaraki Prefecture in 1999. After several billion yen was spent, the project was ended in one year on the grounds that the government did not want to give off a mistaken impression to the public.

"(Authorities) perhaps thought that people would think that they were anticipating a nuclear power plant accident if they had developed robots for accidents," Hirose said

I just love that excuse to explain why an apparent technological lead could not be demonstrated by implementing practical applications.

 

[PietKuip]

Interesting video here, nut I don't know geographiacally where from?



Oh there's a map a few minutes in.

Seems to be in Fukushima City. That meter is detecting beta radiation from surfaces.

 

[AntonL]

Same strange saw tooth pattern in dry well #6 for dose rate.
http://atmc.jp/plant/rad/?n=6

that is actually the spent fuel temperature of unit 6 - dry well dose rates have never been published by Tepco.

 

[clancy688]

Interesting video here, nut I don't know geographiacally where from?

Oh there's a map a few minutes in.

And a map of contamination around site here.

Fukushima City - more than sixty km from the plant.

 

[MiceAndMen]

(I apologise should this been posted earlier)

http://www.asahi.com/english/TKY201104240109.html


I just love that excuse to explain why an apparent technological lead could not be demonstrated by implementing practical applications.

Recognized as the world leader in robotic technology...

I don't recognize them as such. A leader, yes, but not the leader. Except for their automobile manufacturing robots, most of what I see from there revolves around whimsical toys and amusements. Call me when they land a couple on Mars and have them drive around for a few years.

 

[jlduh]

Interesting video here, nut I don't know geographiacally where from?

The main interest of this video is that it shows clearly a phenomenon that has to be understood by anybody who wants to (try to) link measurements and risks for human health. It shows that in the very same area, measurements in microSv/h can HUGELY vary depending on how and where the measurement is done (and this is very often the origins of disputes between associations and autorities: meaning of measurements depending on how the measurement is done).

Which means that any measurement disclosed (also for the global measurements in the areas in the 20 or 30 kms areas) has to be taken as an indication but not a true picture of reality when trying to assess the mid or long term risks for human health (especially when trying to compare those to "thresholds" or "limits" or whatever).

A good part of contamination is related to dust particles carrying contamination, which will concentrate in geographical areas (leopards spots) and in one of such areas, there will be also a huge variability in places where particles will concentrate. The video shows for example that at the output of draining pipes from roofs, where particulates deposited with rain for example, the contamination concentrates. In a few meters distance, the levels can vary from one or several orders of magnitude.

The problem is that if you measure it at a level of let say 1-1,5m (your hands level) you'll get a measure very different than if you measure it at ground level, and at ground level, this measure will also widely vary depending on the spots. Everything that can move the particles is of factor of variation or concentration, and this can of course evolve with time: wind can relocate particles that were on the ground (so people can inhalate them), water will concentrate the dust all along its paths, etc.

The real exposition of a person living at a certain place for a given time will depend more on what he will do, breath, drink and eat, than on a global measured (but measured how?) value then extrapolated for a year, because this doesn't take into account the complexity of the processes involved.

In classical studies done for ongoing chemical pollutions out of many factories in their "normal" activities, the calculations done to assess the excess risks of cancers for example into one exposed population take into account a huge number of parameters, such as what people will eat and so on. And these will only give you a rough idea of some average exposition (that's why safety coefficient are put into place, to try to take into account the fact that measurements and dispersions are complex matters).

It is known for example that in the case of children, a major path for contamination to enter their body is through "ingestion of soil". This looks always surprising but not so much when you consider what they do during the day and also the fact that their mouth is not at the same level than ours as adults!
This info illustrates very well the point: http://www3.nhk.or.jp/daily/english/26_19.html

(even if this is maybe a "good" decision, it seems more a psychological related one than an effective one... because who can think of dust particles not moving from around with the wind and rain and redepositing?

This remembers me a lot of silly stuff done at Tchernobyl to try to fix contamination. Environment and contamination processes are somewhat different in essence than just the basic housekeeping cleanliness psychology: "this is dirty, this is clean"!

Ok, doing something is sometimes the only thing to do, so...

Hope this video and these explanations will help to understand the difficulty for REALLY assessing exposition risks for various people in a given area. Reality is always more complex than models and comparison of a number to an other number!

 

[artax]

Thanks Jlduh,..
That is very relevant,.. in fact I did hear that the first 'criticality' achieved on the planet was a natural event,thousands of years before the human race got going, anyone have any knowledge of this?

Here you go!

http://www.livescience.com/75-natural-nuclear-reaction-powered-ancient-geyser.html

There are quite a few videos out there, using only Japanese script in their titles and key words.
I used the japanes script fot contamination, posted lat page to search you tube japan... it would be good to have a list of RELEVANT words, written in Japanese.
Anyone know the best way to get translations?

 

[Jorge Stolfi]

Some remarks about the recently found Unit #3 "blueprints" (two vertical sections and one service floor layout):

* As far as I can tell, the pillar sructure of Unit #4, substantially exposed by the explosion, matches quite well the blueprints of #3. That is rassuring, it fits with the hope that #2--#4 are structurally similar.

* On the other hand, the three "blueprints" are amateurish. The first two seem to have been done by hand with ruler & compass; the floorplan was done with some random illustration software. Neither is a professional drawng. The north-south cut is the worst; the vertical positions of several features (such as the basment floor) do not match the numbers given along the side. also, the SFP and dryer storage pool in that drawing do not match the florplan. The east-west cut seems more accurate.

* According to the floorplan, and confirmed by the photos, the 4 corner pillars are exacly alike. The other 5 pillars in the west face are all alike and equally spaced, and are exactly mirrored on the east face.On the other hand, the 4 wall pillars on the north and the 4 on the south are irregularly sized and spaced, and there are only two mirrored pairs (1 and 2 from west to right). The south pillars 3 and 4 are aligned with the tracks of the FHM, and bracket the SFP. North pillars 3 and 4 likewise bracket the dryer storage pool.

* Looking at the pictures it is hard to keep in mind the true scale of the objects. Those pillars are massive, about 1.5 by 1.3 meters in cross section (if the drawings are to be trusted).

* In particular, pillar 4 on the south face was twice as wide as the others; posibly 2 m wide by 1.5 m deep. nevertheless, the part that used to exist above the service floor got completely blasted away, leaving the broad "window" that allows us to peer into the SFP.

* The mysterious "hole" that appears in the pre-explosion photos is not in the 3rd row of panels from the top, but on the 4th. After the explosion, the hole got buried by debris; only the top edge is barely visible. It is on the "3rd storey" of the building (the service floor being the 5th). That storey has a rather low ceiling (5.4 m minus the concrete slab). Its floor is on the same level as the floor of the SFP (which is near to southeast corner of the building, only 6-8 meters away from the "hole".

 

[Dmytry]

The main interest of this video is that it shows clearly a phenomenon that has to be understood by anybody wants to (try to) link measurements and risks for human health. It shows that in the very same area, measurements in microSv/h can HUGELY vary depending on how and where the measurement is done (and this is very often the origins of disputes between associations and autorities: meaning of measurements depending on how the measurement is done).

Which means that any measurement disclosed (also for the global measurements in the areas in the 20 or 30 kms areas) has to be taken as an indication but not a true picture of reality when trying to assess the mid or long term risks for human health (especially when trying to compare those to "thresholds" or "limits" or whatever).

A good part of contamination is related to dust particles carrying contamination, which will concentrate in geographical areas (leopards spots) and in one of such areas, there will be also a huge variability in places where particles will concentrate. The video shows for example that at the output of draining pipes from roofs, where particulates deposited with rain for example, the contamination concentrates. In a few meters distance, the levels can vary from one or several orders of magnitude.

The problem is that if you measure it at a level of let say 1-1,5m (your hands level) you'll get a measure very different than if you measure it at ground level, and at ground level, this measure will also widely vary depending on the spots. Everything that can move the particles is of factor of variation or concentration, and this can of course evolve with time: wind can relocate particles that were on the ground (so people can inhalate them), water will concentrate the dust all along its paths, etc.

The real exposition of a person living at a certain place for a given time will depend more on what he will do, breath, drink and eat, than on a global measured (but measured how?) value then extrapolated for a year, because this doesn't take into account the complexity of the processes involved.

In classical studies done for ongoing chemical pollutions out of many factories in their "normal" activities, the calculations done to assess the excess risks of cancers for example into one exposed population take into account a huge number of parameters, such as what people will eat and so on. And these will only give you a rough idea of some average exposition (that's why safety coefficient are put into place, to try to take into account the fact that measurements and dispersions are complex matters).

It is known for example that in the case of children, a major path for contamination to enter their body is through "ingestion of soil". This looks always surprising but not so much when you consider what they do during the day and also the fact that their mouth is not at the same level than ours as adults!

Hope this video and these explanations will help to understand the difficulty for REALLY assessing exposition risks for various people in a given area. Reality is always more complex than models and comparison of a number to an other number!

I've been telling about this since the day 1 on some other forum. Precisely in the words of how dose rates differ between drain pipe, ground, and holding counter up in the air!
This spots situation is absolutely no surprise for those who know how Chernobyl fallout fell.

This is also highly relevant to the LNT model. The LNT 'opponents' who declare the doses safe / below threshold, use the average doses, where the averaging is justified by LNT (the deaths given by LNT are same regardless of dose distribution as long as doses stay below those resulting in acute symptoms, so you can use the averaging), but then they deny LNT when it comes to counting the cancer deaths.

 

[artax]

I guess you've discussed the source of this concrete block? primary containment Vessel??

http://www.youtube.com/watch?v=8P_Glae6vLc&feature=related

And the narrative may be a little OTT but there miught be some new video here

 

[Jorge Stolfi]

Starting a POV-Ray model of unit 4:

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/fig_un4_service_storey_E_face.png
http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/fig_un4_service_storey_S_face.png

 

[biffvernon]

Regarding the video of measurements from Fukushima city, taking the instrument display at face value i.e. dated 24th April and the numbers showing micro Sieverts per hour, ranging from very little to over ten and sometimes approaching 100 uSv/hr near the pipe ends, I would conclude that any child playing in the dust at those locations is in trouble.

Average values are not a good indicator of harm. A roof draining via gutters to a downpipe opening to a gravel soakaway is going to concentrate fallout dust by a couple of orders of magnitude.

300 000 people live in this city. Some of the smaller ones will play near drainpipes.

 

[liamdavis]

I knew about water under pressure - A couple of years ago, I happened to heat a glass of water under oil in the microwave, and I saw it blow liquid all over the place quite suddenly. And yet, knowing that the building 4 explosion happened with no obvious source, it took me a week and several wrong guesses to think of the steam explosion mechanism.

When I did the arithmetic, I was shocked at the amount of energy that could be held in the water.

Chris

Good catch! Since reactor #4 was shut down it is probable that a lot of maintenance was going on that had no relation to the planned shut-down. Many machines might require being taken out of service to do maintenance work and this might not be allowed during operations. A long list of "work to be done at the next shut-down" would have accumulated and if any of this involved a container of oil in the vicinity of the SPF during the earthquake it could be the source of oil covering the water. It would only require a thin film.

Too much has happened since, and we may never know for certain, but it adds an additional element of interest.
liam

 

[Borek]

That's a good idea. I wonder if there is a way to do that so it is avilable for reference without searching through over 5000 posts. Maybe Borek or Astronuc can help us find a way to do it.

This is tricky. The only way I can think about is to edit the very first post in the thread so that it contains kind of "executive summary" for the current situation/state of knowledge/list of known problems. That has to be done by one of the Mentors, as there is a limit to how long posts can be edited by their own authors.

I have no problems with doing the editing every few days, but the text has to be prepared by someone else. If anyone is ready and willing to do it, please contact me by PM.

 

[jlduh]

To clarify for educational purposes what is called "leopards spots", i post this map of the contaminated zones around Tchernobyl plant:

http://www.netimago.com/image_193374.html

Then, as in a fractal object, if you could zoom more on each spot like with google earth, you would see appearing more local spots with concentration of contamination, and so on until the level of what the guy in the video does going in the corners of walls or at the end of draining pipes.

THIS IS VERY IMPORTANT TO UNDERSTAND WHAT THE REALITY IS BESIDES ISOLATED NUMBERS.

In the case of Tchernobyl it is interesting to see that there has been a big redeposition area in the north east direction of the plant, and that there was apparently no real continuous gradient to describe the affected zones: there is a zone with much less redeposition in between the two main zones. Difficult from this map to conclude that the circle is the best shape to describe the risks zone...

 

[artax]

crikey, these videos of robots in a spacially chaotic environment really show how adaptable and capable our bodies are!
They really need to advance that ASIMO somewhat to have him be of any use in there.

http://nuclearstreet.com/nuclear_po...kushima-nuclear-reactor-buildings-042104.aspx

It has me wondering what sort of radio-protective clothing is available and what percentage of ionizing radiation can they stop?

They really need a man (good climber/absailer) to run round the place with a camera!

 

[PietKuip]

The main interest of this video is that it shows clearly a phenomenon that has to be understood by anybody who wants to (try to) link measurements and risks for human health. It shows that in the very same area, measurements in microSv/h can HUGELY vary depending on how and where the measurement is done (and this is very often the origins of disputes between associations and autorities: meaning of measurements depending on how the measurement is done).

This GM meter obviously detected mostly beta radiation. It is difficult to express those countrates in microSievert per hour.

The measuremens that get published by professional monitoring sites measure gamma radiation. For constant surface contamination, the gamma dose does not depend with distance to the ground (unless one gets really high up and the atmosphere is shielding). That is why the American maps are good.

 

[artax]

this map might give some explosion clues?

http://www.yomiuri.co.jp/dy/national/T110425003601.htm
and another here... sorry if these have already been posted.

http://blogs.forbes.com/oshadavidson/2011/04/25/tepco-reveals-radiation-map/

 

[jlduh]

Pietkuip, are you saying that that kind of equipement doesn't measure also gamma radiations?

If i look at any Radex 1503 spec, both beta and gamma are in the spec (with à 25% possible error indicated, but an increased sensitivity below 300 Kev)

Capteur tube Geiger-Müller
Gamme de mesures
5 à 999 µRem/h ou
0,05 à 9,99 µSv/h

Energies des rayons X et gamma détectés 0,1 à 1,5 Mega electron Volt (MeV)
Energies des particules bêta détectées 0,35 à 1,5 Mev
Incertitude de la mesure en X et Gamma 25 % *

 

[|Fred]

..

The measures provided are airborne unsheltered, you should expect higher concentration as one radioactive material contained in a cloud precipitate to water then eventually when the water evaporate. Hence food and water consumption restriction.

Airborne radiation is by far the main concern as there is not much that can be done to prevent contamination of the general public.

As for the rest you are perfectly correct one should not make the assumption one should not
lick pipes on the street, Children should avoid playing on outdoor playground, one should leave there shoes at the door. If not understood, general population should be educated so.

 

[artax]

I'm pretty sure in Japan they always leave shoes outside, very rude not to.

Which is lucky

 

[Dmytry]

Pietkuip, are you saying that that kind of equipement doesn't measure also gamma radiations?

If i look at any Radex 1503 spec, both beta and gamma are in the spec (with à 25% possible error indicated, but an increased sensitivity below 300 Kev)

Capteur tube Geiger-Müller
Gamme de mesures
5 à 999 µRem/h ou
0,05 à 9,99 µSv/h

Energies des rayons X et gamma détectés 0,1 à 1,5 Mega electron Volt (MeV)
Energies des particules bêta détectées 0,35 à 1,5 Mev
Incertitude de la mesure en X et Gamma 25 % *

also, keep in mind that beta comes only from top suface of gravel anyway, whereas gamma from entire depth. There may very well be more gamma than beta hitting the counter. The counter detects gamma primarily by it knocking out electrons from the walls (i.e. the same way).

 

[jlduh]

Fred, I'm not going to be too sarcastic but your remark remembers me what has been said for years by asbestos industry: cancers risks are related to improper use of the product, and workers have to be "trained" to use it properly. We all know here where we ended up with it (and it's still not ended with the coming dead).

Here we talk about general population and children. That kind of measures can be taken for short emergency and/or transitory situations, but for on going life, this is a joke.

 

[PietKuip]

Pietkuip, are you saying that that kind of equipement doesn't measure also gamma radiations?

If i look at any Radex 1503 spec, both beta and gamma are in the spec (with à 25% possible error indicated, but an increased sensitivity below 300 Kev)

It does measure gamma, but a GM tube is not very sensitive to it. Most of it passes through it, without being registered.

You can determine whether it is measuring gamma or beta by putting it in an aluminum, plastic or wooden box. That will stop the betas, but hardly effect the gamma intensity.

 

[Dmytry]

It does measure gamma, but a GM tube is not very sensitive to it. Most of it passes through it, without being registered.

You can determine whether it is measuring gamma or beta by putting it in an aluminum, plastic or wooden box. That will stop the betas, but hardly effect the gamma intensity.

or you can also look at actual specs and see the accuracy for gamma and beta.

 

[ascot317]

I'm pretty sure in Japan they always leave shoes outside, very rude not to.

Which is lucky

A lot of houses (walls/windows) an are not properly isolated, which is kinda unlucky.

That's what I wondered about when they declared the 30km-zone earlier.

 

[jlduh]

For Radex 1503:

accuracy for gamma: 25% but increased sensitivity below 300 Kev (125% at 100 Kev and 200% at 60 Kev)

So basically what you are saying Pietkuip anyway is that this equipement is essentially minimizing the actual measurement if more gamma are present.

 

[PietKuip]

For Radex 1503:

accuracy for gamma: 25% but increased sensitivity below 300 Kev (125% at 100 Kev and 200% at 60 Kev)

So basically what you are saying Pietkuip anyway is that this equipement is essentially minimizing the actual exposure if more gamma are present.

I am saying that those readings are mostly beta radiation. It is not really correct to express the readings as a dose rate in sievert per hour.

With such meters it is easy to get readings that are much higher than the numbers given by authorities. That may undermine the confidence that the population has that the authorities are telling them the truth. But these are different instruments, and the official Japanese gamma dose rates can be relied on.

It seems that the conversion from countrate to dose is done for 300 keV gammas. That is also a bit crude, but it is the best that one can do with such a simple device. The real deviations occur when there is also beta radiation.

 

[MadderDoc]

ID'ing fragments of wall panels from unit4 east wall, the lower part of row 2, column 3:

The lower part of these fragments correspond to the floor of the service deck, close to the mouth of the reactor cavity. (See attachment with THawk photos of the fragments, and a markup photo of the building)

The fragments appear to have fallen almost vertically to the foot of the wall. They have landed very much on top of other debris, along with roof material. They have some curiously linear edges, which might indicate something about how the finishing layer to the wall was made. The remains on the building appears to negate that these fragments could have formed part of a designed opening. (Whereas in the _neighbouring_ row 2, column 4, there are remains left on pillars of something looking like a window frame, and the whereabouts of the corresponding wall panel/window filling is unknown.)

The wall fragments may have initially hung on in tatters to the building after a powerful blast of the hydrogen on the upper floor -- only to be shattered loose very shortly thereafter, by a more subdued and upwards directed poof, of the hydrogen present in the open reactor cavity.