Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[LabratSR]

"instrument failure" is only found in these documents (what source is this?), not in the original tepco datasets.

Look at the bottom of the second page under the CAMS data.

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/11052406_level_pr_data_1u-e.pdf


From here.

http://www.tepco.co.jp/en/nu/fukushima-np/index-e.html

 

[SteveElbows]

Using dodgy computer translation of small parts of that large document, I have been able to learn more about the containment damage that appears to factor into their analysis. There is loads more that I am not even going to try to get my head round using computer translation, for now I was content to get some idea of the timing they were considering for this containment damage:Reactor 1:

At the time of analyzing concerning the hypothesis of vapor phase leakage from 1 Containment Vessel, in order it is to adjust to the value of the Containment Vessel pressure which is really measured, the Containment Vessel (the dry well (calling below “D/W”,) you supposed the leakage (approximately φ3 cm) from the vapor phase section from earthquake occurrence in after approximately 18 hours. In addition, enlargement (approximately φ7 cm) of leakage was supposed in after approximately 50 hours. However, to be hypothesis in regard to analysis to the last, whether it is unconformity of measurement value and the analytical value due to the problem of the or meter side which really has leakage from Containment Vessel (D/W), at present time it is unclear.

Reactor 2:

In order it is to adjust to the value of the Containment Vessel pressure which is really measured at the time of analyzing concerning the hypothesis of vapor phase leakage from 2 containment vessels, the Containment Vessel (D/W) leakage from the vapor phase section (approximately φ10 cm) you supposed from earthquake occurrence after approximately 21 hours. In addition, in the same way the pressure control room of 3/15 (calls below “S/C”) the strange noise which occurs in near was supposed in boundary, the Containment Vessel (S/C) leakage from the vapor phase section (approximately φ10 cm). However, to be hypothesis in regard to analysis to the last, whether it is unconformity of measurement value and the analytical value due to the problem of the or meter side which really has leakage from the Containment Vessel, at present time it is unclear.

As for what they say about reactor 3, I cannot rely on the computer translation enough to even begin to describe their position on that.

If the computer translation is even half accurate, it certainly does not sound like their analysis is based on anything more sturdy than the data we already know about, and it may be a crude approximation just to make all the other numbers work in their analysis.

As for what caused these containment failures, I have only translated little bits so far but I would not be surprised if its the same theory as we have heard in the past - things get too hot and/or under too much pressure, and a variety of weak spots are the candidates to break first, whether they be gaskets or whatever. But they may have additional thoughts on this that I cannot understand yet, and as I said I am especially unclear what their analysis of reactor 3 is exactly.

 

[MiceAndMen]

[Posted in other thread, copying here.]

From this morning's paper:

http://www.asahi.com/special/10005/TKY201105240733.html

Summary: Unit 3 ECCS (Emergency Core Cooling System?) may have been damaged by the earthquake, before the tsunami arrived.
(According to analysis released by TEPCO on the 24th.)

Add: I guess the analysis is the report EX-SKF was talking about: http://www.tepco.co.jp/cc/press/betu11_j/images/110524a.pdf
Ooh, this looks juicy. Good bedtime reading.

Beginning on page 215 are diagrams of all 6 Daiichi RPVs that show instrumentation levels. I'll be waiting for the English version of the entire report myself, but the diagrams are pretty clear by themselves for now.

 

[andybwell]

Not likely.

Look at the 5th picture. At the top of the photo you see the skeletal remnants of the wall of the 3rd and 4th floors. There are two massive steam pipes running behind and below the building...the lower edge of the lower pipe is almost perfectly aligned with the floor level of the 3rd floor. Follow the floor line of the third floor down down from that back wall along the right side of the building, then across the front side of the building near the bottom of the photo. There is nothing but air remaining above that level, except for a bit of roof debris which you can see through. Is that the top of the primary containment vessel, as well as the top of the reactor itself?

http://cryptome.org/eyeball/daiichi-npp/daiichi-photos.htm

 

[StrangeBeauty]

Look at the 5th picture. At the top of the photo you see the skeletal remnants of the wall of the 3rd and 4th floors. There are two massive steam pipes running behind and below the building...the lower edge of the lower pipe is almost perfectly aligned with the floor level of the 3rd floor. Follow the floor line of the third floor down down from that back wall along the right side of the building, then across the front side of the building near the bottom of the photo. There is nothing but air remaining above that level, except for a bit of roof debris which you can see through. Is that the top of the primary containment vessel, as well as the top of the reactor itself?

http://cryptome.org/eyeball/daiichi-npp/daiichi-photos.htm

No. The reactor and containment are on the opposite side of the building. If you are truly interested, you need to look back in the thread to see the discussion of the layout of the building (with many excellent pictures), and the ramifications of your highly unlikely scenario.

Extraordinary claims require extraordinary evidence. E.g. show us a clear picture of the primary containment cap or its fragments. (Actually I'd like to see a clear picture of the caps regardless of their location and state)

 

[MiceAndMen]

Hm? What distorsion?

(As someone else pointed out, your reputation is fine. It's the webcam that has a poor one.)

The pictures from that JNN webcam present a distorted view of reality. The original image is an SD (Standard Definition) 4:3 aspect ratio frame that has been stretched out to fill a 16:9 frame and falsely presented as HD.

Here's what it looks like (16:9 faux HD stretch-O-vision):

And here's what it should look like (4:3 SD aspect ratio):

The live feed is a distraction at best and at worst it provides grist for the rumor mill. It has lead to all kinds of absurd speculation including:

• The reactors are belching smoke (at least twice a week someone posts this)
• Building 4 is leaning
• Reactor 3 is on fire

My opinion is that that webcam has produced zero useful observations since Unit 3 exploded. I have never tuned into the live feed; it shows nothing of interest unless you're looking for a weather report. I wish they would just turn the damn thing off, at least until something new and interesting actually happens at the site.

 

[MiceAndMen]

Look at the 5th picture. At the top of the photo you see the skeletal remnants of the wall of the 3rd and 4th floors. There are two massive steam pipes running behind and below the building...the lower edge of the lower pipe is almost perfectly aligned with the floor level of the 3rd floor. Follow the floor line of the third floor down down from that back wall along the right side of the building, then across the front side of the building near the bottom of the photo. There is nothing but air remaining above that level, except for a bit of roof debris which you can see through. Is that the top of the primary containment vessel, as well as the top of the reactor itself?

http://cryptome.org/eyeball/daiichi-npp/daiichi-photos.htm

The topic and all those pictures were discussed here weeks ago. The photos were dissected and analyzed thoroughly. I respectfully suggest that you go back and review that discussion and how the photos were marked up and annotated. If you find a new angle that hasn't been discussed yet I'm sure people will be happy to engage you in conversation about it.

 

[andybwell]

Also for the sake of adding the final bit of info I have left to add to conversations about round equipment and the layout of the reactor fuel service floor, I think the same video also shows the reactor cap of unit 4, has this been noticed before?

Watching the video from around the 2 mins 46 seconds mark to get bearings in relation to the yellow containment cap that we know very well already. Watch as the camera starts to show stuff that is further to the right of this yellow cap. Pause it around 3 mins 6 seconds. There is a bit of circular equipment visible at the top of the image, I believe this is still attached to the reactor cap after removal of the cap, and with that in mind a fairly faint image of a dark cap becomes apparent. They look like they are leaning noticeably, but I am wary of how much things can be misjudged due to angle image is being shot at, etc.

I apologize for not doing due diligence research before posting.

http://www.youtube.com/user/modchannel#p/a/u/0/ZKFGavZ_rf4

 

[andybwell]

The topic and all those pictures were discussed here weeks ago. The photos were dissected and analyzed thoroughly. I respectfully suggest that you go back and review that discussion and how the photos were marked up and annotated. If you find a new angle that hasn't been discussed yet I'm sure people will be happy to engage you in conversation about it.

I was looking at those pictures for the first time today and the hackles went up on the back of my neck as to the enormity of this catastrophe and its ramifications if it cannot be "stabilized"

 

[StrangeBeauty]

I apologize for not doing due diligence research before posting.

http://www.youtube.com/user/modchannel#p/a/u/0/ZKFGavZ_rf4

Oops I wasn't completely clear. I meant for units 1-3. The unit #4 bright yellow cap has been visible in many pics for weeks now.

...and its ramifications if it cannot be "stabilized"

I share your concern. I think the characterization of the situation being 'static' is generally accepted as a description of the recent past. All aspects of the situation are certainly not 'stabilized' and there are many unique problems to conquer in trying to get the site safe, and cleaned up, not to mention trying to get significant swaths of the countryside habitable again. I'm not sure anyone here thinks that it can't eventually be 'stabilized' but how long that takes and the final cost in earth, air, water, money, and humanity is up for speculation.

It is difficult to assess the probability of something new going catastrophically wrong at this point (e.g. SPF4 collapsing; another explosion; etc.).

 

[Azby]

The Daily Yomiuri Online has posted diagrams describing fuel melting in reactors 1,2 and 3, based on info from TEPCO. Anyone care to comment on the plausibility and/or likelihood of these scenarios?

http://www.yomiuri.co.jp/dy/national/T110524006012.htm
http://www.yomiuri.co.jp/dy/photo/DY20110525102058990L0.jpg

 

[andybwell]

No. The reactor and containment are on the opposite side of the building. If you are truly interested, you need to look back in the thread to see the discussion of the layout of the building (with many excellent pictures), and the ramifications of your highly unlikely scenario.

Extraordinary claims require extraordinary evidence. E.g. show us a clear picture of the primary containment cap or its fragments. (Actually I'd like to see a clear picture of the caps regardless of their location and state)

"the ramifications of your unlikely scenario" I was unable to locate them in this thread. Could you elaborate or give me a link?

 

[andybwell]

Oops I wasn't completely clear. I meant for units 1-3. The unit #4 bright yellow cap has been visible in many pics for weeks now.


I share your concern. I think the characterization of the situation being 'static' is generally accepted as a description of the recent past. All aspects of the situation are certainly not 'stabilized' and there are many unique problems to conquer in trying to get the site safe, and cleaned up, not to mention trying to get significant swaths of the countryside habitable again. I'm not sure anyone here thinks that it can't eventually be 'stabilized' but how long that takes and the final cost in earth, air, water, money, and humanity is up for speculation.

It is difficult to assess the probability of something new going catastrophically wrong at this point (e.g. SPF4 collapsing; another explosion; etc.).

"All aspects of the situation are certainly not 'stabilized' " Given your obvious expertise, what is a potential likely outcome a year, two, or ten from now?

 

[andybwell]

Oops I wasn't completely clear. I meant for units 1-3. The unit #4 bright yellow cap has been visible in many pics for weeks now.

It is difficult to assess the probability of something new going catastrophically wrong at this point (e.g. SPF4 collapsing; another explosion; etc.).[/QUOTE

Would an earthquake 6.9 or greater cause a catastrophe? The chances of such an earthquake appear possible.

 

[sp2]

No. The reactor and containment are on the opposite side of the building. If you are truly interested, you need to look back in the thread to see the discussion of the layout of the building (with many excellent pictures), and the ramifications of your highly unlikely scenario.

Extraordinary claims require extraordinary evidence. E.g. show us a clear picture of the primary containment cap or its fragments. (Actually I'd like to see a clear picture of the caps regardless of their location and state)

If you're going to sneeringly dismiss somebody (as so many on this forum spend so much energy doing), don't you think you ought to at least try and make a little more sense than than the OP you're so sneeringly dismissing?

<<The reactor and containment are on the opposite side of the building. >>

I have no idea what you're trying to say there, but I'm quite sure what you did say makes no sense whatsoever.

 

[AntonL]

Soil contamination from Fukushima crisis comparable to Chernobyl:
http://english.kyodonews.jp/news/2011/05/93120.html

TOKYO, May 25, Kyodo

Radiation released by the crippled Fukushima Daiichi nuclear power plant has caused soil contamination matching the levels seen in the Chernobyl disaster in some areas, a researcher told the government's nuclear policy-setting body Tuesday.

''A massive soil decontamination project will be indispensable before residents in those areas can return,'' said Tomio Kawata, a research fellow of the Nuclear Waste Management Organization of Japan, at the meeting of the Japan Atomic Energy Commission, which sets policies and strategies for the government's nuclear power development.

According to Kawata, soil in a 600 square kilometer area mostly to the northwest of the Fukushima plant is likely to have absorbed radioactive cesium of over 1.48 million becquerels per square meter, the yardstick for compulsory migration orders in the 1986 Chernobyl catastrophe

 

[sp2]

(As someone else pointed out, your reputation is fine. It's the webcam that has a poor one.)

The pictures from that JNN webcam present a distorted view of reality. The original image is an SD (Standard Definition) 4:3 aspect ratio frame that has been stretched out to fill a 16:9 frame and falsely presented as HD.

Here's what it looks like (16:9 faux HD stretch-O-vision):
View attachment 35894

And here's what it should look like (4:3 SD aspect ratio):
View attachment 35892

The live feed is a distraction at best and at worst it provides grist for the rumor mill. It has lead to all kinds of absurd speculation including:

• The reactors are belching smoke (at least twice a week someone posts this)
• Building 4 is leaning
• Reactor 3 is on fire

My opinion is that that webcam has produced zero useful observations since Unit 3 exploded. I have never tuned into the live feed; it shows nothing of interest unless you're looking for a weather report. I wish they would just turn the damn thing off, at least until something new and interesting actually happens at the site.

To you, and all you guys who seem to spend a good deal of your leisure-time in mocking anybody who ever suggested that there might possibly be an issue with the srtuctural integrity of Building 4, I have three questions:

1. What exactly are the circled regions in your picture supposed to be telling us?
You seem to have circled anything that looks distinctly non-parallel to the picture frame.
So? Your point is what, exactly?
2. What's the big deal about the stretching of the format in the live-vid? It would exaggerate any deviations from vertical, I suppose, but it wouldn't create them, would it?
3. Does it occur to you guys that there's probably a *reason* that TEPCO keeps publicly discussing the need to 'stabilize the building' and 'shore it up to prevent collapse?'
(I've heard them make statements to this effect at least three different times now.)
Do you think they keep saying those things because they're 'hysterical,' or because they've been stupidly fooled by the distortion of the format on the web-cam?

Or, do you think, just possibly, they might actually think they have particular cause to worry about the prospect of the building (or part thereof) collapsing?

I'm sorry, but the snotty condescension of many voices here, masquerading as supreme rationality when it's sometimes really quite the opposite, is a little tough to take after a while.

 

[zapperzero]

The Daily Yomiuri Online has posted diagrams describing fuel melting in reactors 1,2 and 3, based on info from TEPCO. Anyone care to comment on the plausibility and/or likelihood of these scenarios?

http://www.yomiuri.co.jp/dy/national/T110524006012.htm
http://www.yomiuri.co.jp/dy/photo/DY20110525102058990L0.jpg

The timeline for #1 looks like a textbook example, don't know about the others.

 

[AntonL]

on 23 May NHK reported http://www3.nhk.or.jp/daily/english/23_25.html

The operator of the damaged Fukushima nuclear power plant is continuing the transfer of highly radioactive water from 2 reactor buildings to storage facilities within the compound, but the facilities are expected to become full within 3 or 4 days

on 24 May NHK report the following NISA instruction to Tepco http://www3.nhk.or.jp/daily/english/24_38.html

The agency has also asked TEPCO to wrap up a plan for storing and treating radioactively contaminated water at the plant by June 1st.

this is a surprise no finalised water storage and treating plans
(If I remember correctly the Areva plant should be operating by 1st June.)

 

[westfield]

snip >

3. Does it occur to you guys that there's probably a *reason* that TEPCO keeps publicly discussing the need to 'stabilize the building' and 'shore it up to prevent collapse?'< snip.

Yes there would be a reason TEPCO stated that but why jump to the conclusion that they are talking about the entire building?

TEPCO have never mentioned anything specific regarding stuctural integrity of the RB of unit #4 APART from their desire to shore up the underside of the SFP.

To accomplish that they will cut a sizable hole in the outside wall and some inside walls of RB #4 to gain suitable access to the underside of the SFP and will put workers in there to do the work.

TEPCO are planning to use what will amount to tens of tons of steel and concrete to provide support to the underside of the pool.

I'm not TEPCO but it doesn't seem unreasonable to assume that if TEPCO thought for a moment the whole building was facing collapse they would not be proposing to cut holes in it, put workers in there and at the same time add significant additional load to the base structure.

Sure the upper levels of RB #4 are trashed and have significant structural damage, the remaining sections are definitely leaning this way and that. There is no doubt, it's plain to see. That means very little in regard to the overall stuctural integrity of the rest of the building - we can't see that, let alone make a judgement on its integrity.

We have seen the images of inside the building lower levels and how relatively intact things are there - if we had only seen those images and not the images of the upper levels would we think the building is about to fall over?

 

[MiceAndMen]

To you, and all you guys who seem to spend a good deal of your leisure-time in mocking anybody who ever suggested that there might possibly be an issue with the srtuctural integrity of Building 4, I have three questions:

1. What exactly are the circled regions in your picture supposed to be telling us?
You seem to have circled anything that looks distinctly non-parallel to the picture frame.
So? Your point is what, exactly?

I didn't want to post that last pic but couldn't find a way to un-attach it after I posted. Please ignore it. If you must know, the circled parts highlight a few things in the image that contribute to the overall optical illusion of tilt. The articulating boom of the Putzmeister is angled off-vertical. There is something amiss on the upper reaches of the pillar in the SE corner of the building. The entire roof line - or what's left of it - goes down and to the right. Even the JNN logo font is tilted. All these visual artifacts contribute to the overall false impression that the image gives to the viewer.

2. What's the big deal about the stretching of the format in the live-vid? It would exaggerate any deviations from vertical, I suppose, but it wouldn't create them, would it?

It's a big deal because it is not a faithful representation of the scene. It exaggerates the horizontal scale and presents the viewer with false information that clearly has an exaggerated horizontal bias. Add in the circled bits of the last image and you wind up with a picture that is dishonest. Would you watch a 4:3 SD television show stretched out to 16:9 on your HD television for any length of time? I wouldn't. The scenes presented are not accurate reproductions of the source material.

3. Does it occur to you guys that there's probably a *reason* that TEPCO keeps publicly discussing the need to 'stabilize the building' and 'shore it up to prevent collapse?'

They need to shore up the supports under the SFP because the entire building's structural integrity has been compromised. Its ability to bear the load of the SFP has been reduced. But there does not appear to be - by any publicly available credible evidence - an apparent and imminent danger of the building collapsing at the SE corner. Those who espouse that view are (in my opinion) perhaps a bit hysterical. Distorted webcam feeds only encourage them. That's why I wish they would just turn it off. It would be good for the hysteria quotient.

I'm sorry, but the snotty condescension of many voices here, masquerading as supreme rationality when it's sometimes really quite the opposite, is a little tough to take after a while.

I have no idea what you're on about here.

 

[swl]

It appears that TEPCO has engineers reading this forum:

However, if they study the CAMS data... then they would note a spike in the readings between 13:00 and 15:25 on 15 March which would make the event even a couple of hours earlier, - a nice correlation between a theoretical study and actual field readings.

And now this TEPCO quote from businessweek:

"It (TEPCO) revised the time the No. 1 reactor melted to within 15 hours of the quake, an hour earlier than it gave last week when it announced the damage to the reactor was worse than thought.

 

[htf]

Well, at the beginning of Gunderson's video above, he is saying :we know that n°1 reactor was already in course of meltdown and the containment was leaking before tsunami hit...

Is this supported by some statements or data or facts?

There recently was an article in a German online magazine. According to this article the story is based on insider information and an analysis by Mitsuhiko Tanaka.
http://www.spiegel.de/wissenschaft/technik/0,1518,762868,00.html

A Tepco insider has leaked information to the press about what happened after the earthquake in reactor #1: workers entered the building to check for damages but after they opened the air-proof safety door their dosimeters went off and they immediately evacuated. From the dosimeter readings they estimated radiation levels of 300 mSv/h inside the building which they therefore suspected to be filled with radioactive steam. The article uses the word Gebäude (building) but I think what they really mean is containment.

On a press conference in March, Mitsuhiko Tanaka (a former Babcock Hitachi employee) had speculated that pipes or something else must have been damaged by the earthquake. He based his analysis on the following facts: Early failure of the cooling system of reactor #1, high radiation levels immediately after the earthquake, rapidly falling cooling water levels in reactor #1, the low pressure (0.8 MPa) of the RPV and an increase in the pressure of the containment ( 0,8 MPa) 12 hours after the earthquake. He said that many experts must have come to the same conclusion but have decided to remain silent.

If this is all true I can imagine that Tepco and NISA prefer the Tsunami theory. This would raise serious question about the susceptibility to earthquakes of all NPPs in Japan.

 

[yakiniku]

2. What's the big deal about the stretching of the format in the live-vid? It would exaggerate any deviations from vertical, I suppose, but it wouldn't create them, would it?

I am not joining the conversation regarding the possibility that reactor #4 is leaning.

Regarding your question, assuming that the algorithm was a linear stretch algorithm, then what you say is accurate. However, a non-linear algorithm could be applied to stretch a 4:3 image to 16:9, whereby retaining the linearity of the central area of the frame but stretching the periphery.

 

[zapperzero]

Soil contamination from Fukushima crisis comparable to Chernobyl:
http://english.kyodonews.jp/news/2011/05/93120.html

There's no point to even start a decon until the accident is over, which it isn't. Cesium and Strontium have a lot of time to bio-accumulate and leach into groundwater. What are they going to do to clean this up? Demolish every house, uproot every tree, take out all the turf and 10-25 centimeters of soil beneath that? Pump the streams dry and cart off the rocks underneath? What will they do with the equipment afterwards? How about the rubble? How about the spots that become re-contaminated while this is going on, from rain and dust and whatever? Where will the replacement fertile soil come from?

Cue the experts... "oh decontaminating the arable land is easy, you just plow it under extra deep and spread a bit of clean topsoil above, the answer to pollution is dilution". This was tried after Chernobyl, also at Hanford. Doesn't work so well. Soil lives. The gently-glowing earthworms you bury find their way to the surface. Plants put roots into the contaminated layer, sucking up cesium. Groundwater swells upwards with seasonal rains in the low places like marshes and river valleys. Hot-spots form in a semi-random manner, where before there was "reclaimed" land.

Oh, just for giggles... what would you do to decon a flooded rice paddy? Will it still be a rice paddy when you're done with it?

 

[elektrownik]

What about one of units earthquake damage ? There was something in Discovery movie, US tepco worker told that after quake there was crack in reactor building ? But which unit ?
Here: http://www.youtube.com/watch?v=PTQ-Jky_fr8&feature=player_detailpage#t=203s
And here: http://www.youtube.com/watch?v=PTQ-Jky_fr8&feature=player_detailpage#t=289s

 

[clancy688]

There recently was an article in a German online magazine. According to this article the story is based on insider information and an analysis by Mitsuhiko Tanaka.
http://www.spiegel.de/wissenschaft/technik/0,1518,762868,00.html

When I first read the article (and the following ones) I was burning with anger. They only quoted an engineer who suspected (correctly I assume) that several pipes were damaged by the earthquake. Which resulted in cooling water leaking from the RPV.
But then in the following articles, spiegel concluded that those damages MUST HAVE resulted in the meltdown (Tsunami wasn't even needed to kill the plant). Which's hilarious. I tried to tell them about their misunderstanding twice by posting in the article related threads. But both posts got deleted.

 

[zapperzero]

I am not joining the conversation regarding the possibility that reactor #4 is leaning.

Regarding your question, assuming that the algorithm was a linear stretch algorithm, then what you say is accurate. However, a non-linear algorithm could be applied to stretch a 4:3 image to 16:9, whereby retaining the linearity of the central area of the frame but stretching the periphery.

I took another screenshot today. A look at the towers will tell you the camera is tilted to the left, in relation to the entire site.

 

[Rive]

There's no point to even start a decon until the accident is over, which it isn't. Cesium and Strontium have a lot of time to bio-accumulate and leach into groundwater. What are they going to do to clean this up? Demolish every house, uproot every tree, take out all the turf and 10-25 centimeters of soil beneath that?

Well, one thing is sure: they cannot give up the entire area.

There are methods to 'wash' contaminated soil, so I think they will license something from Areva or develop some new stuff for it.

Hot-spots form in a semi-random manner, where before there was "reclaimed" land.

It'll be a long fight. But if they need that area then they have to win it. Lots of regular checks, soil replacements, again and again... I see no other way.

 

[zapperzero]

Well, one thing is sure: they cannot give up the entire area.

Why not? I am well aware that Japan has not the area of Ukraine. However, I think the cost of a successful cleanup far outweighs the benefits. An improper cleanup would end up killing people. It would be like living in a minefield. Some parts of Asia are accustomed to exactly that, sadly, but I don't think the average Japanese citizen would like it, even as a prospect, let alone a day to day reality.

Wash the soil from a 600 square Km area? The mighty AREVA can't even muster resources to process a couple thousand tons of low-radioactive water a month. How much more water would be needed? Let's say you just give the first 10 cm of topsoil a quick soak, say mix equal volume water and soil, drain out the rad sludge and call it a day.

You'd have to deal with 6x10⁷ tons of contaminated water. Sixty million metric tons

 

[Rive]

Why not? I am well aware that Japan has not the area of Ukraine. However, I think the cost of a successful cleanup far outweighs the benefits. An improper cleanup would end up killing people. It would be like living in a minefield. Some parts of Asia are accustomed to exactly that, sadly, but I don't think the average Japanese citizen would like it, even as a prospect, let alone a day to day reality.

As you said, they have more limited amount of area than Ukraine. Otherwise they must develop something to threat contaminated areas effectively anyway: accumulation works everywhere, so hot spots will be formed even outside the exclusion zone.

IMO every wastewater pipe and treatment facility within in 200km radius (or even more) is a potential 'minefield'. Even now.

Wash the soil from a 600 square Km area? The mighty AREVA can't even muster resources to process a couple thousand tons of low-radioactive water a month.

Excess capacities are always hard and long to set up.

 

[PietKuip]

Why not? I am well aware that Japan has not the area of Ukraine. However, I think the cost of a successful cleanup far outweighs the benefits. An improper cleanup would end up killing people. It would be like living in a minefield.

The real estate would have little value. It will be difficult to sell agricultural products from the area, when even tea leaves from south of Tokyo are more radioactive than the limits. The supply of housing will be much greater than demand - what parents want to raise a family there? And then there is this weird "shunning" of people from contaminated areas in Japan.

Make this into an area for forestry.

 

[clancy688]

You could try a similar decontamination as in Chernobyl. Only decontaminate streets and buildings.
As long as the people stay inside the decontaminated zone, traveling and working should be possible. There's no sense in decontaminating a meadow, for example.
Nobody wants to live in such a zone, and decontamination of everything there is impossible, as already stated. But they could still try to decontaminate only the most necessary spots in order to establish an economoy in that region again.

 

[tsutsuji]

Demolish every house

Why demolish ? Shouldn't washing the outer surface of walls and roof be enough ?

Here is what a French expert team wrote before the Fukushima crisis (in May 2010) about the actions to be undertaken in the zone where populations are allowed to live, albeit under restrictions. The following is therefore not applying to the relocation zone (the most contaminated area where people are not expected to have their dwelling any longer), but it gives an idea of what can/must be done :

The main contamination reduction measures listed hereafter are detailed in Appendix 9, Part 3 of the Guide entitled “Nettoyage dans le milieu bâti (hors zone d’éloignement éventuel)” [Building Clean-Out (excluding possible clearing zone)]:
 clean-out operations in buildings, to be undertaken by specialised teams, such as the Fire and Rescue Brigade, Civil Security or private enterprises;
 contamination fixation/stabilisation techniques aimed at limiting loose dust or skin contamination;
 measures to be taken by residents, such as:
- washing floors with a moist cloth, taking care to move from the washed zones to zones assumed to be still contaminated;
- cleaning aeration grids and home ventilation systems;
- vacuuming furniture surfaces, rugs and carpets.

Whatever the case, measures shall be adjusted to the level and type of risk involved. For instance, it is not specifically recommended that individuals wash their vehicles in ZPPs. Likewise, any roads cut off during the emergency phase may return to use without having been cleaned. The use of these vehicles and roads will trigger only very low additional exposure, which is negligible when National Preparedness Guide for Emergency Phase Way-Out Working Document - May 2010 58/67 compared to the resources that would have to be mobilised to carry out the cleaning and the related environmental restrictions. It should be noted that outdoor decontamination activities are less of a priority then indoor decontamination. The disposition of waste products will need to be decided before such activities could begin. However, residents may themselves take part in the decontamination of their own property once such work begins (i.e. garden, lawn, etc.).

p.57-58 http://www.asn.fr/index.php/content/download/29754/182511/file/Guide+Sortie+Phase+Urgence_UK.pdf

p.36/55 of the cited Appendix 9, Part 3 ( http://www.asn.fr/index.php/content/download/25882/155306/file/Guide+SPU+Annexes+explicatives+V0+14mai2010.pdf ) has the following comment after detailing firehose and high pressure cleaning :"The efficiency is about 30% for buildings' walls and roofs and 50% for roads and pavements if the action is undertaken within one week after a dry deposit."

 

[zapperzero]

Why demolish ? Shouldn't washing the outer surface of walls and roof be enough ?

Here is what a French expert team wrote before the Fukushima crisis (in May 2010) about the actions to be undertaken in the zone where populations are allowed to live, albeit under restrictions. The following is therefore not applying to the relocation zone (the most contaminated area where people are not expected to have their dwelling any longer), but it gives an idea of what can/must be done :

Why don't you read the references you post? Those are guidelines for decon in the case of a moderate accident - defined as less than 24 hours of continuing radiation release. We're way past that.

EDIT: also, if you wash, where does the water go? It is radioactive now, remember?