Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[MiceAndMen]

It is clear from the shadows that this photo has been taken well before noon, (the sun is towards the seaside). The shadow of the south vent stack does not hit the south east corner of the unit 4 building until after noon.

Agree it was taken before noon, but the stack is SE of the #4 reactor building (the center pipes are anyway) so I would expect a shadow of the top to hit that wall in the morning. This picture shows a different kind of hole in the exact same spot:
http://www.flickr.com/photos/digitalglobe-imagery/5522088312/sizes/l/in/photostream/
It looks like a hole shaped for Mickey Mouse or perhaps the Easter Bunny. It's hazy and hard to tell what it is exactly, but it does look like a hole and it does not look rectangular. I think it, too, is a shadow from the vent stack.

Then there are the two pictures at the bottom of this page:
http://cryptome.org/eyeball/daiichi-npp2/daiichi-photos2.htm

They show that a shadow from the stack could, under the right circumstances, be projected onto the east side of the building. Curiously, and in favor of your hypothesis however, the last picture on that page does show a green patch of some sort right near where this "hole" is located! Very interesting.

This is another case where a lack of precise drawings and site layout/dimensions hamper our armchair analyses. IF we knew where the south vent stack was in relation to bldg #4 and IF we knew exactly how high the stack is, it would be trivial to set up a 3D simulation of the sun traversing the sky on the dates in question and determine, once and for all, whether the vent stack could cast a shadow on the building of the right shape and size in that spot. But, alas, that is data we do not have.

 

[MadderDoc]

The two attached photos of unit 4 are frames from a video taken by a helicopter that overflew the facility on March 11th, shortly after the tsunami.

They show the same thing as the other photos I've posted on this matter: an apparent hole in the lower south end of the east wall, and this right after the earthquake. A visual effect of a cast shadow can here be entirely ruled out, the sunlight was simply too diffuse to cast any perceptible shadow at the time of these photos.

 

[MadderDoc]

Agree it was taken before noon, but the stack is SE of the #4 reactor building (the center pipes are anyway) so I would expect a shadow of the top to hit that wall in the morning. This picture shows a different kind of hole in the exact same spot:
http://www.flickr.com/photos/digitalglobe-imagery/5522088312/sizes/l/in/photostream/
It looks like a hole shaped for Mickey Mouse or perhaps the Easter Bunny. It's hazy and hard to tell what it is exactly, but it does look like a hole and it does not look rectangular. I think it, too, is a shadow from the vent stack.

Then there are the two pictures at the bottom of this page:
http://cryptome.org/eyeball/daiichi-npp2/daiichi-photos2.htm

They show that a shadow from the stack could, under the right circumstances, be projected onto the east side of the building. Curiously, and in favor of your hypothesis however, the last picture on that page does show a green patch of some sort right near where this "hole" is located! Very interesting.

This is another case where a lack of precise drawings and site layout/dimensions hamper our armchair analyses. IF we knew where the south vent stack was in relation to bldg #4 and IF we knew exactly how high the stack is, it would be trivial to set up a 3D simulation of the sun traversing the sky on the dates in question and determine, once and for all, whether the vent stack could cast a shadow on the building of the right shape and size in that spot. But, alas, that is data we do not have.

Yes that could be fun :-), however not necessary at all. We have ample access to photos taken from satellites indicating how the shadow of the south vent tower travels across the building of unit 4. Furthermore we have photos of the putative hole, taken under diffuse daylight, completely mooting the question.

The green blob in the photo from cryptome.org is quite interesting, although the photo is rather earlier, from 2010 according to the caption -- but, can it really be a coincidence that it is in the same spot? What could that green blob be, since it does not appear to be a constant feature of the building? I shall have to think about that.

Re the mouse/bunny shape, it appears from photos that it could be produced by the holes upper edges not being teared off cleanly. Indeed from a satellite photo from the same period looking more directly from the south along the east side, it appears that some irregular piece of wall is protruding, above the putative hole. See the attachment.

 

[MiceAndMen]

The green blob in the photo from cryptome.org is quite interesting, although the photo is rather earlier, from 2010 according to the caption -- but, can it really be a coincidence that it is in the same spot? What could that green blob be, since it does not appear to be a constant feature of the building? I shall have to think about that.

The green blob is very interesting indeed. Cryptome says the picture was taken on 18 September 2010, which was before the shutdown for the core shroud replacement job. Maybe they did some work in that part of the building in preparation for that task. It seems like an odd out-of-the-way spot for an access hole, however.

@Jorge, this is for you, too ... these are the links for the Building 3 cross sections I found.

So what is on that level of the building? From 2 diagrams I found in a couple of Japanese-language PDFs I believe (if Unit 4 is similar to Unit 3) the floor at that elevation coincides with the bottom of the SFP, which we have placed in the SE corner of the building, yes?

This PDF shows a diagram on page 17 comparing Unit 3 RB construction with Unit 5:

http://www.pref.fukushima.jp/nuclear/info/pdf_files/100805-1.pdf​

Unit 3 is on the left. Notice the bottom of the SFP coincides with the floor at OP 26.9 meters.

Now have a look at page 35 of this PDF:

http://www.tepco.co.jp/nu/f1-np/press_f1/2010/pdfdata/bi0508-j.pdf​

The top drawing is the same as the earlier one, so I'm assuming the drawings on this page are also for Unit 3 (even though I can't read Japanese). The second drawing on that page is an elevation view from the other direction. It looks like OP 26.9m is also the elevation of the low-bay part of the building to the east towards the turbine building (height above ground = 16.9 m = 55 ft.). This would be the "deck" area that the stairs on the south side of the building lead to. It would also be the lower extremity of your hole. On the same level as the bottom of the SFP.

Make of it what you will. Your diffuse lighting arguments re. shadows are persuasive, but I'm not at the point yet where I'm convinced it's a hole. We shall see! (It is good that we can disagree and be civilized and friendly about it.)

 

[NUCENG]

The CalTech document is a great collection of pictures and data relating to the Fukushima accident. I read it 10 days ago but glad to see it posted here again for all to consider.

I think it will be determined at some time in the future's investigation that like most of the bad things that happened resulted because of the total station blackout - a beyond design basis event. IOW, they were screwed when the tsunami took out the generators.

The venting system relies on fans and filters to remove particles before discharge up the stack. Apparently, little thought was given to a natural draft type back-up venting plan. Top goal was preventing radioactive release. Being so focused on that primary goal, they designed systems that INCREASED such releases in a severe accident!


What I have not seen discussed (and in 300 pages I may well have missed it!) is service water. Was service water (sea water for cooling) available after the EQ? Would it have been available after the tsunami IF electrical power had remained available? Once the suppression pools reached 100 degrees C even the steam driven pumps would have become useless. Just how long does it take to heat the SC to 100C without service water cooling available? Did high SC temperature fail the steam driven pumps or did loss of battery power cause that?

Emergency service water pumps would have been abvailable until the loss of AC. General service water woulld have been available in a reduced form. Most plants can power a reduced number of service water pumps in an emergency. I have no information about Fukushima service water.

The TEPCO reports in the first couple of days recorded when suppression pool temperatures reached 100 degC because they had to report that as an emergency event. Unit 1 had no steam driven pumps. They only had an isolation condenser. Units 2 and three were using steam driven pumps. Unit 2 stuck with RCIC until the suppression pool reached 100 degC. At some point for reasons I haven't seen, operators at unit3 switched to HPCI which requires higher steam flow than RCIC. Later they tried to switch back to RCIC, but failed. Unit 3 reported a loss of residual heat removal as an emergency port. I think this was before the suppression pool reached 100 degC. Use of SRVs would have continued to heat the suppression pool. In the US, Emergency Operating Procedures call for manual depressurization when the suppression pool reaches a temperature whre the suppression function is lost.

 

[etudiant]

The green blob is very interesting indeed. Cryptome says the picture was taken on 18 September 2010, which was before the shutdown for the core shroud replacement job. Maybe they did some work in that part of the building in preparation for that task. It seems like an odd out-of-the-way spot for an access hole, however.

@Jorge, this is for you, too ... these are the links for the Building 3 cross sections I found.

So what is on that level of the building? From 2 diagrams I found in a couple of Japanese-language PDFs I believe (if Unit 4 is similar to Unit 3) the floor at that elevation coincides with the bottom of the SFP, which we have placed in the SE corner of the building, yes?

This PDF shows a diagram on page 17 comparing Unit 3 RB construction with Unit 5:

http://www.pref.fukushima.jp/nuclear/info/pdf_files/100805-1.pdf​

Unit 3 is on the left. Notice the bottom of the SFP coincides with the floor at OP 26.9 meters.

Now have a look at page 35 of this PDF:

http://www.tepco.co.jp/nu/f1-np/press_f1/2010/pdfdata/bi0508-j.pdf​

The top drawing is the same as the earlier one, so I'm assuming the drawings on this page are also for Unit 3 (even though I can't read Japanese). The second drawing on that page is an elevation view from the other direction. It looks like OP 26.9m is also the elevation of the low-bay part of the building to the east towards the turbine building (height above ground = 16.9 m = 55 ft.). This would be the "deck" area that the stairs on the south side of the building lead to. It would also be the lower extremity of your hole. On the same level as the bottom of the SFP.

Make of it what you will. Your diffuse lighting arguments re. shadows are persuasive, but I'm not at the point yet where I think it's a hole. We shall see! (It is good that we can disagree and be civilized and friendly about it.)

While unit 4 has the same power rating as units 2 and 3, it is a Hitachi built unit, while 2 and 3 were GE-Toshiba.
There may therefore be differences in the design specifics and the building layout.

 

[MiceAndMen]

While unit 4 has the same power rating as units 2 and 3, it is a Hitachi built unit, while 2 and 3 were GE-Toshiba.
There may therefore be differences in the design specifics and the building layout.

That is true. This news article, though, does state...

A midlevel TEPCO official also said money was a big reason why repairs and changes to the No. 1 plant were not made.

"The blueprints for the reactor cores at the No. 1 plant were bought 'as is' by Toshiba Corp. from General Electric Co., so the priority at that time was on constructing the reactors according to those blueprints," the official said.

When the Fukushima No. 1 plant was being built, Japan was importing technology from the United States and learning from a more advanced nuclear power nation.

The No. 1 plant was considered a "learning experience."

A former TEPCO executive said, "The Fukushima No. 1 plant was a practice course for Toshiba and Hitachi Ltd. to learn about GE's design on a trial-and-error basis."

With the exception of the No. 6 reactor, the other five reactors at the Fukushima No. 1 plant are Mark I boiling-water reactors developed by GE.

http://www.asahi.com/english/TKY201104060126.html

I would bet money that the interior layouts of units 2-4 are quite similar, if not identical in most respects. Their external dimensions seem to be identical, as was their power output. I wouldn't be a lot of money on it, but I would bet some.

 

[rowmag]

I guess the building must have a door - even a pretty big door to get equipment in and out. But that 'hole' does seem a long way above ground level and there's no sign of it in the earlier picture:

[PLAIN]http://img.ibtimes.com/www/data/images/full/2011/03/15/74732-tokyo-electric-power-co-s-fukushima-daiichi-nuclear-plant-no-4-reactor.jpg[/QUOTE]

I think it is a door. If you look really closely at biffvernon's picture, you can see the outlines of it on the right-hand side of the area that looks like a hole in other pictures. When it is open, it swings out to cover the left (as seen from the outside), so the square "hole" seen in other pictures is the combination of the inside of the open door and the interior of the building seen through the open door frame.

Note that there is a staircase going down the south side of reactor building 4 from the roof area accessed by that door.

I'm guessing that the door was either already open at the time of the earthquake for whatever reason, or it was opened by workers evacuating the building afterwards.

The bit of protruding concrete noted by MadderDoc may be a little rectangular rain guard over the door, to keep rainwater sliding down the wall away from the door seals, or else possibly a lighting fixture:

 

[Jorge Stolfi]

service floor BP linked on the webpage was posted here originaly few dozen pages down and is not from Fukushima.

OK.

If there indeed was a hole in the east wall of unit4, before the explosions, as these photos appear to be showing, there is no need to hypothesise about an extra explosion to cause it, nor that someone made the hole deliberately. We need no further assumptions because, we know that the building had just before been exposed to an extraordinarily strong earthquake.

I believe that just opposite to that hole, on the west side, there is a covered gallery that leads into the building, passing under the elevator that is used to move fuel casks in and out of the building. Perhaps the earthquake displaced a truck that was parked inside (or a cask that was about to be lifted, or whatever) and it hit the wall, knocking out one of the panels.

It seems that building #1 has very thick solid walls that get thicker in the lower levels, while buildings 2--4 have a skeleton of concrete columns with a relatively thin concrete shell loosely anchored on them. The hole seems to be on the lowest row of "panels". In the after-the-explosion pictures that row is almost buried under the rubble.

But indeed the building appears to have had such a opening, however at the wall panel at row 2, column 4. Note the distinctly different way this panel has been blown off, with remaining sharp edges and paint deco along those edges. We see the same phenomenon at unit 3, the exact same position, row 2, column 4. The opening that has been made in the east wall of unit 2 is also in this position.

I vaguely recall a statement that those panels were weaker on purpose, meant to be knocked out in case of overpressure. I have also heard conflicting explanations about the #2 holes: some say they were made by the workers to avoid H2 buildup, some say they were caused by the explosion in #2, some say they were a consequence of #3's explosion. Which version is correct?

 

[rowmag]

Second question: The east wall appears to be divided into vertical sections, a broad one in the middle, somewhat narrower sections to the right and left of that, and again, to the right and left of those sections, two even narrower sections towards the ends of the wall. What produces this appearance?

Perhaps they are lightning rod conduits, or rainwater drainage pipes. According to the #1 blueprints, the roof is slanted by 30cm in the E-W direction (although in #1 the East is lower). They seem to follow the main concrete pillars of the building, but offset to one side or the other, rather than down the pillar's midline.

They look like rainwater drainage pipes to me.

 

[Danuta]

Don't know if this link has already been posted. It's the latest video-ed press briefing plus all the previous ones. The 60 odd minutes left me with a strange empty feeling but someone may get something interesting out of it, especially the foreign press' question and answer period.

http://http://nettv.gov-online.go.jp/eng/prg/prg2107.html"

 

[Jorge Stolfi]

@Jorge, this is for you, too ... these are the links for the Building 3 cross sections I found.

They look authoritative. Thanks!

 

[Jorge Stolfi]

I believe that just opposite to that hole, on the west side, there is a covered gallery that leads into the building, passing under the elevator that is used to move fuel casks in and out of the building.

Oops, forget, this does not seem to be correct. The "hole"is two stories up from the cask entrance. But it is the correct height for that floor. See the blueprint of #3 below:

 

[rowmag]

Update on the sub-drain isotope ratio measurements (time-series plots begin on page 3):
http://www.meti.go.jp/press/2011/04/20110423004/20110423004-5.pdf

 

[NUCENG]

OK.



I believe that just opposite to that hole, on the west side, there is a covered gallery that leads into the building, passing under the elevator that is used to move fuel casks in and out of the building. Perhaps the earthquake displaced a truck that was parked inside (or a cask that was about to be lifted, or whatever) and it hit the wall, knocking out one of the panels.

It seems that building #1 has very thick solid walls that get thicker in the lower levels, while buildings 2--4 have a skeleton of concrete columns with a relatively thin concrete shell loosely anchored on them. The hole seems to be on the lowest row of "panels". In the after-the-explosion pictures that row is almost buried under the rubble.



I vaguely recall a statement that those panels were weaker on purpose, meant to be knocked out in case of overpressure. I have also heard conflicting explanations about the #2 holes: some say they were made by the workers to avoid H2 buildup, some say they were caused by the explosion in #2, some say they were a consequence of #3's explosion. Which version is correct?

In US BWRs there are two blowout panels on the 5th floor, refueling area. These panels will pop at a few inches of water pressure. They are designed to vent off building pressurization during high energy line breaks or negative pressure events like a tornado.

 

[triumph61]

I have looked at the Video shortly taken the Tsunami. There is also a hole at Unit 4.
Also look at the light Dark Spot at Unit 2. At the same Position there is later the hole.
http://www.youtube.com/watch?v=LUGAbMVG-qc&feature=related

 

[NUCENG]

Update on the sub-drain isotope ratio measurements (time-series plots begin on page 3):
http://www.meti.go.jp/press/2011/04/20110423004/20110423004-5.pdf

Looks like this sample point is still acting different. Same observations and discussion as in my last post.

 

[PietKuip]

Don't know if this link has already been posted. It's the latest video-ed press briefing plus all the previous ones. The 60 odd minutes left me with a strange empty feeling but someone may get something interesting out of it, especially the foreign press' question and answer period.

http://http://nettv.gov-online.go.jp/eng/prg/prg2107.html"

The Times asked why the new rules forcing people out of the evacuations zones did come now.

Part of the answer (translation starting at 32:00 in the video) was that one could not permit people to stay there, because if they came out of the exclusion zone, their contamination might be a danger for others.

Sorry, but this sounds like bollocks to me.

The press conference ended with a question about SPEEDI, why it does not give data. The basic answer was that the system does not have good input data, so that it cannot make forcasts.

So this expensive system is completely useless when Japan needs it...

 

[clancy688]

ZAMG was the only source that provided overall emission estimates from an early period.

There's also an IRSN estimate from March 22th: http://www.irsn.fr/FR/Actualites_presse/Actualites/Documents/NI-terme-source-22032011-tableau.pdf

90.000 TBq I131 and 10.000 TBq C137 - that's close to the numbers NISA and NSC released on April 12th.

Still confused though because even if the data was accurate only up to the date of issue ,12/4/2011 that still gives 30 x5,000TBqs of Ce137 average daily emission or 2 x chernobyl in one month as opposed to i x every 100 years.

You can't say "5000 TBq * 30". I'd expect that between 5000 and 15.000 TBq C137 escaped between March 11th and March 21th. Not per day. Overall number!
That's 10% of Chernobyl. And from March 21th on we can use these 0,14 TBq C137 per hour. And that's what I meant with "Chernobyl every 110 years".

 

[kujala]

The government is taking TEPCO's side concerning the leak into the sea:
http://english.kyodonews.jp/news/2011/04/87554.html

It's probably based on the TEPCO's explanations found in this paper:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110421e2.pdf

But we all remember there were significant leaks into the sea even in March. For instance on 25th of March there was a sudden and significant rise in the radioactive density of seawater:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110326e5.pdf

So any ideas what caused this rise of radiation if not the leak they were able to stem on 6th of April?

 

[Dmytry]

The Times asked why the new rules forcing people out of the evacuations zones did come now.

Part of the answer (translation starting at 32:00 in the video) was that one could not permit people to stay there, because if they came out of the exclusion zone, their contamination might be a danger for others.

Sorry, but this sounds like bollocks to me.

very dangerous bollocks too.
http://www.independent.ie/world-new...nied-care-over-radiation-concern-2601963.html

 

[MiceAndMen]

The Times asked why the new rules forcing people out of the evacuations zones did come now.

The Times... as in London or New York? Today is the first day of the government takeover of news dissemination regarding the reactors. They are admitting foreign journalists in and allowing them to ask questions? That would be a good thing. At least until they decide that the foreign journalists are asking difficult questions and declares them persona non grata at the pressers.

 

[rowmag]

Looks like this sample point is still acting different. Same observations and discussion as in my last post.

Thank you, NUCENG.

 

[rowmag]

The Times asked why the new rules forcing people out of the evacuations zones did come now.

Part of the answer (translation starting at 32:00 in the video) was that one could not permit people to stay there, because if they came out of the exclusion zone, their contamination might be a danger for others.

Sorry, but this sounds like bollocks to me.

That's not really a good translation of what he said. He said people were not supposed to be in the evacuation zones to begin with, but there were some people disobeying and going in and out or even staying there, so the government has decided they need to take further steps. Having people going in and out of the zone is not good for the region, it is not good for the people themselves, and they might be bringing out contaminated materials.

(Note, as backdrop, there have been some problems with people going into the region to break into houses and steal stuff from the empty houses.)

 

[PietKuip]

That's not really a good translation of what he said. He said people were not supposed to be in the evacuation zones to begin with, but there were some people disobeying and going in and out or even staying there, so the government has decided they need to take further steps. Having people going in and out of the zone is not good for the region, it is not good for the people themselves, and they might be bringing out contaminated materials.

So the interpreter misinterpreted? My transcription of her translation of the problematic sentence:
"... individuals who would enter these areas because if they come out of these regions the radiation contamination of these individuals may affect other people outside of this area. Therefor such a decision had been made."

I suppose the people sitting there would have had sufficient passive knowledge of English to be able to correct her?

 

[Dmytry]

re: contaminated people.
http://www.sott.net/articles/show/2...-Contagion-Evacuees-Turned-Away-From-Shelters
How did they translate the radioactive contamination to Japanese, I wonder?

In Russian during Chernobyl, the word used is best approximated as "endirtying" and the slang for radioactive stuff is "dirt" and contaminated items "dirty", that is very appropriate because it pretty much is dirt that is 'glowing' (another slang), in the sense of radiating the gammas and betas (except you don't see the glow except when it is already highly dangerous). Very good word choices IMO for explaining it to public.

I don't read news in Russian often, but I've looked - and now they use the word that means something like contagion (or the end result of contagion). Everything is so dumbed down now on all levels. It really doesn't matter what words you use when you know what it is and you think in specific, but for public that does not know, it matters a lot.

There's also an IRSN estimate from March 22th: http://www.irsn.fr/FR/Actualites_presse/Actualites/Documents/NI-terme-source-22032011-tableau.pdf
10.000 TBq C137

Would be great to compare it to Chernobyl estimates from 1.5 months after ;) .
I don't think its very comparable because winds from Chernobyl did blow straight at the parties who were performing independent measurements, rather than into the ocean. There's far larger margin for plausible underestimation than Soviet Union had.

 

[MadderDoc]

<..>

@Jorge, this is for you, too ... these are the links for the Building 3 cross sections I found.

So what is on that level of the building? From 2 diagrams I found in a couple of Japanese-language PDFs I believe (if Unit 4 is similar to Unit 3) the floor at that elevation coincides with the bottom of the SFP, which we have placed in the SE corner of the building, yes?

This PDF shows a diagram on page 17 comparing Unit 3 RB construction with Unit 5:

http://www.pref.fukushima.jp/nuclear/info/pdf_files/100805-1.pdf​

Unit 3 is on the left. Notice the bottom of the SFP coincides with the floor at OP 26.9 meters.

Now have a look at page 35 of this PDF:

http://www.tepco.co.jp/nu/f1-np/press_f1/2010/pdfdata/bi0508-j.pdf​

The top drawing is the same as the earlier one, so I'm assuming the drawings on this page are also for Unit 3 (even though I can't read Japanese). The second drawing on that page is an elevation view from the other direction.

That's a mighty fine catch you have there, mate. They come very handy. EW _and_ NS sections of unit 3! On leafing further through the Tepco documents, I find there's a schematic floorplan of the service floor of unit 3 on page 28 in this pdf (see also attachment below, with the schematic tentatively x/y scaled):

http://www.pref.fukushima.jp/nuclear/info/pdf_files/100805-6.pdf​

It looks like OP 26.9m is also the elevation of the low-bay part of the building to the east towards the turbine building (height above ground = 16.9 m = 55 ft.). This would be the "deck" area that the stairs on the south side of the building lead to. It would also be the lower extremity of your hole. On the same level as the bottom of the SFP.

Make of it what you will. Your diffuse lighting arguments re. shadows are persuasive, but I'm not at the point yet where I'm convinced it's a hole. We shall see! (It is good that we can disagree and be civilized and friendly about it.)

Yes, I like that too. My observations as to lighting/shadows are not fit to prove that it is a hole we see in unit 4 in those photos. They are fit to disprove that it is a shadow. And I dare say, they do so more than persuasively :-) Rather, they do it forcefully compellingly, not to say: conclusively. Whatever it is, it is not a shadow.

 

[|Fred]

http://www.pref.fukushima.jp/nuclear/info/pdf_files/100805-6.pdf​

.

At last this does in deed confirm the floor plan we were close to , nice find.
A shame I can't make much of the rest

 

[rowmag]

So the interpreter misinterpreted? My transcription of her translation of the problematic sentence:
"... individuals who would enter these areas because if they come out of these regions the radiation contamination of these individuals may affect other people outside of this area. Therefor such a decision had been made."

Listening again, he said, "その外に出て来た時の放射能の問題もある," or "there is also the problem of radioactivity when [they] come out of there" -- which could be open for interpretation, but I wouldn't render it as implying "contamination of individuals."

But live interpretation is a delicate, difficult process, so I would cut the interpreter some slack.

 

[rowmag]

re: contaminated people.
http://www.sott.net/articles/show/2...-Contagion-Evacuees-Turned-Away-From-Shelters
How did they translate the radioactive contamination to Japanese, I wonder?

In Russian during Chernobyl, the word used is best approximated as "endirtying" and the slang for radioactive stuff is "dirt" and contaminated items "dirty", that is very appropriate because it pretty much is dirt that is 'glowing' (another slang), in the sense of radiating the gammas and betas (except you don't see the glow except when it is already highly dangerous). Very good word choices IMO for explaining it to public.

The word generally used is 放射能, radioactivity. No need for dysphemisms.

 

[Astronuc]

The problem in the evacuation zone is two-fold: 1) exposure of anyone within the zone, and 2) the possibility of transporting radioactive particles outside of the zone when leaving. The government doesn't want uncontrolled or untraceable exposure, i.e., they don't want the problem growing bigger than it already has.

As for inside the zone, the safest place is actually in doors, since the deposition is on outside surfaces. The problem for someone wanting to stay inside the zone is that if they go in and out of a dwelling, they may carry radioactive material inside the dwelling.

As far as I know, the government allowed some flexibility in the evacuation zone, but now the exclusion is mandatory.

 

[rowmag]

I find there's a schematic floorplan of the service floor of unit 3 on page 28 in this pdf (see also attachment below, with the schematic tentatively x/y scaled):

http://www.pref.fukushima.jp/nuclear/info/pdf_files/100805-6.pdf​

https://www.physicsforums.com/attachment.php?attachmentid=34862&d=1303728878

Interesting notation on that image: "In order to keep foreign matter out of the stored MOX fuel, a plastic cover is placed over the top." Which makes me think of cphoenix's superheated water/steam explosion theory. If pumps stop, and there is a plastic lid over the assemblies, it sounds like his conditions could be satisfied:
https://www.physicsforums.com/showpost.php?p=3254513&postcount=4158

 

[NUCENG]

Interesting notation on that image: "In order to keep foreign matter out of the stored MOX fuel, a plastic cover is placed over the top." Which makes me think of cphoenix's superheated water/steam explosion theory. If pumps stop, and there is a plastic lid over the assemblies, it sounds like his conditions could be satisfied:
https://www.physicsforums.com/showpost.php?p=3254513&postcount=4158

What is there about MOX fuel that requires that kind of protection, that doesn't apply to UO₂ fuel?

 

[rowmag]

The problem in the evacuation zone is two-fold: 1) exposure of anyone within the zone, and 2) the possibility of transporting radioactive particles outside of the zone when leaving. The government doesn't want uncontrolled or untraceable exposure, i.e., they don't want the problem growing bigger than it already has.

Yes, Astronuc. That is exactly what I think was trying to be said.

 

[|Fred]

Looking at unit 4, pink plastic seems there standard procedure when refueling regardless of mox .. that said the pdf seems to be discussing a lot about Mox.

rowmag might find answers within