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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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MiceAndMen
#7993
May22-11, 08:57 PM
P: 276
Quote Quote by Atomfritz View Post
I think the green stuff scattered on photo is no metal. You would see the metal exposed at the breaks, but it is colored uniformly. Looks like plastic to me.
To me it looks like steel or metal with reinfoced webs, but you're probably right about it being plastic. There would indeed be exposed metal at the breaks.

As for the red stuff in the photo, I think they used a "dye bomb" or dropped some paint on the hot spot as a marker.

If I could ask a favor, in the future could you please try and limit the horizontal width of posted pics to 800 or so? Very wide pics make the rest of the page really hard to read!
ElliotLake
#7994
May22-11, 09:04 PM
P: 11
Quote Quote by Atomfritz View Post
I think the green stuff scattered on photo is no metal. You would see the metal exposed at the breaks, but it is colored uniformly. Looks like plastic to me.

I read somewhere in this thread that functional groups in nuclear plants are "color coded", like the "FHM green".

But I doubt that a plastic box would be used in hot areas, for various reasons. It could just be a trash can been hit in the yard by the explosion. (just my unqualified 2 cents)



I am also curious. What could be radiating so much there?



Certainly this is not caused by a screwdriver.

So here my layman's analysis of the image and my thoughts and questions:



What could be this reddish stuff that appears to spread like pigment?

Any idea?

Edit: This stuff also could be bricks. But I doubt that bricks of apparently very low quality are used in NPPs... So I suppose this could be something other... but what?
Highly doubtful it's brick; that's a wrong red for bricks, too bluish-red, too "red" for brick.
Appears too as though whatever the red is, it got there after the pile got pushed together.
Atomfritz
#7995
May22-11, 09:09 PM
P: 74
Quote Quote by MiceAndMen View Post
As for the red stuff in the photo, I think they used a "dye bomb" or dropped some paint on the hot spot as a marker.
This sounds very plausible, thanks!

Quote Quote by MiceAndMen View Post
If I could ask a favor, in the future could you please try and limit the horizontal width of posted pics to 800 or so? Very wide pics make the rest of the page really hard to read!
Oooops... apologizes to all..
I really didn't think of that. *slapping myself*
westfield
#7996
May22-11, 09:35 PM
P: 145
Quote Quote by MiceAndMen View Post
Regarding the Gamma Camera images at http://www.tepco.co.jp/en/news/110311/index-e.html

Does the fact that the Gamma Camera registers significantly on the (broken?) ventilating ducts imply that the electrically powered HVAC fans were actively circulating radioactive material before they lost electric power on 11 March?
Tepco press releases often seem a bit like their plant releases, they do nothing to clear the air.

In this case, are they simply surveying the place, or perhaps looking for a failure point or are they looking to see what equipment can be made serviceable?

If they are looking for a failure point then SGTS ducting outside of primary containment but inside the building would be a good candidate (it's my "favourite" for how hydrogen made it throughout the RB's). The SGTS's projected failure during reactor overpressure "incidents" is what prompted the Direct Torus Vent System retrofit.

However, there are the SGTS ducts, HVAC ducts and others, who knows what the ducting system is in the pictures, who knows why tepco surveyed it and who knows why they showed it to us.


There are lots of docs on the net going into GE Mark 1 BWR "issues" in depth but this one does two of the more likely failures in brief -
Page 4 of this document has a brief section on the Brunswick plant stress test that revealed the BWR Mk1 containment dome lifting off it's seals at 70psi and also the SGTS issue as mentioned above.
jmelson
#7997
May22-11, 11:17 PM
P: 48
Quote Quote by Atomfritz View Post
I think the green stuff scattered on photo is no metal.
That green stuff may be Borotron, or similar boron-loaded plastic for neutron absorption. I see it at the accelerator labs I visit, you can get it in sheets and blocks to fabricate shielding from.

Jon
Atomfritz
#7998
May23-11, 12:09 AM
P: 74
Quote Quote by ElliotLake View Post
Highly doubtful it's brick; that's a wrong red for bricks, too bluish-red, too "red" for brick.
Yes, this really disturbs me.
And a closer looking also makes me doubt that this is just dye.
See this zoomed-in image.



This discoloration of bricks is often caused by abnormal high temperatures, like with metals.
Over-heated red pottery often discolors into crimson-bluish if it gets burnt too hot.

Another known cause of brick discoloration are chemical contaminations.

And why are these bricks (or whatever this is) in such a bad shape?
If these are hard bricks (as commonly used in modern times), such a pulverization makes me think that they originally probably have been very near the epicentre of an explosion.

Or, maybe like damaged oven/furnace bricks. Like being burst by steam expansion when heating up a wet oven.
If you look at the bricks closely, you also can find blackish-looking discolorations.
Like the soot you find when you demolish an old not-perfectly-tight chimney. You see where smoke has passed/leaked through.

In fact, these bricks look to me very similar to rotten chimney bricks, decomposed by the effects of heavily changing temperatures, humidity, condensing as boilt out, and salts and acids.
Really not the sort of things I would expect in a NPP.

To me these discolorations seem a bit too dark just to be mortar.
Could it be earth, on this sandy site?
Or, could it be precipitated black smoke?

So, what I don't understand - where came these "bricks" from?
And why do they look so odd?


Could it be possible that an opening in the reactor building has been closed by putting masonry into it?

Maybe due an open hole for some heavy equipment that had to be put with a crane into a building floor after raw construction has been finished?
Or by some modification involving closing no-longer needed openings?

If so, then this could have a series of imaginable consequences.
First, it would have been a weak point in the side walls - possibly ripping them outward instead of relieving the pressure in direction to the ceiling, resulting in the peculiar shape of RB #3?
Second, as most initial pressure then would be relieved when this "structural breaking point" opens, maybe a contaminated equipment part could have separated and blown out of the building?
And so, finally, resulting in a radiation obstacle for the pumping teams, so it just got bulldozed into the next corner?

(Sorry for my long unqualified and scientifically unfounded post. I just have a bit of construction experience, nothing nuclear.)
Grumalg
#7999
May23-11, 12:28 AM
P: 3
Maybe the brick color is due to Iodine? Iodine-129 @ .84% fission yield and 15.7 million year halflife could surely still be around in quantity.
Atomfritz
#8000
May23-11, 12:47 AM
P: 74
Being curious, if i find a clue what the green broken thing could be, I collected the item details in a pic. Looks like sort of container to me.
maybe an expert here can recognize/identify this item?

MiceAndMen
#8001
May23-11, 01:38 AM
P: 276
Quote Quote by westfield View Post
However, there are the SGTS ducts, HVAC ducts and others, who knows what the ducting system is in the pictures, who knows why tepco surveyed it and who knows why they showed it to us.
The PDF on this page, "May 22, 2011 Dose-measurement points by gamma camera..."
http://www.tepco.co.jp/en/nu/fukushi...s/index-e.html

is this file http://www.tepco.co.jp/en/nu/fukushi...10522_01-e.pdf

The first page shows where the pictures were taken from. It looks like they drove the gamma cam bot in through the vehicle portal ("carry-in gate for large stuff") and took pictures straight ahead, and then turned right 90 deg and took some more. The electrical panel on the column with the door hanging off of it is in both pictures. The second picture, then, is from an area near the SW corner of the building with the camera pointing South, while it seems to be pointing East in the first picture.

@Atomfritz : Thank you for resizing that picture.
ElliotLake
#8002
May23-11, 01:43 AM
P: 11
I've no nuclear experience but have built & fired a lot of kilns, and that red substance is nothing like any brick (kiln or otherwise) I've seen. The weird blue red in overburnt bricks goes along with melting, slagging not crumbliness. Boiler bricks would be whitish to white, high duty (high temp/corrosive atmosphere) refractories don't include iron.

It is a puzzle, that largest lump does have a brickish outline, but I can't believe Tepco would have used bricks that way: Japanese knowledge/practice of ceramics is vast and ancient. "Dye bomb" or indicator powder gets my vote.
Maxion
#8003
May23-11, 01:44 AM
P: 36
Quote Quote by Atomfritz View Post
Yes, this really disturbs me.
And a closer looking also makes me doubt that this is just dye.
See this zoomed-in image.



This discoloration of bricks is often caused by abnormal high temperatures, like with metals.
Over-heated red pottery often discolors into crimson-bluish if it gets burnt too hot.

Another known cause of brick discoloration are chemical contaminations.

And why are these bricks (or whatever this is) in such a bad shape?
If these are hard bricks (as commonly used in modern times), such a pulverization makes me think that they originally probably have been very near the epicentre of an explosion.

Or, maybe like damaged oven/furnace bricks. Like being burst by steam expansion when heating up a wet oven.
If you look at the bricks closely, you also can find blackish-looking discolorations.
Like the soot you find when you demolish an old not-perfectly-tight chimney. You see where smoke has passed/leaked through.

In fact, these bricks look to me very similar to rotten chimney bricks, decomposed by the effects of heavily changing temperatures, humidity, condensing as boilt out, and salts and acids.
Really not the sort of things I would expect in a NPP.

To me these discolorations seem a bit too dark just to be mortar.
Could it be earth, on this sandy site?
Or, could it be precipitated black smoke?

So, what I don't understand - where came these "bricks" from?
And why do they look so odd?


Could it be possible that an opening in the reactor building has been closed by putting masonry into it?

Maybe due an open hole for some heavy equipment that had to be put with a crane into a building floor after raw construction has been finished?
Or by some modification involving closing no-longer needed openings?

If so, then this could have a series of imaginable consequences.
First, it would have been a weak point in the side walls - possibly ripping them outward instead of relieving the pressure in direction to the ceiling, resulting in the peculiar shape of RB #3?
Second, as most initial pressure then would be relieved when this "structural breaking point" opens, maybe a contaminated equipment part could have separated and blown out of the building?
And so, finally, resulting in a radiation obstacle for the pumping teams, so it just got bulldozed into the next corner?

(Sorry for my long unqualified and scientifically unfounded post. I just have a bit of construction experience, nothing nuclear.)
Heh, remember occams razor. What would normal red bricks be doing as construction material at a nuclear powerplant? Laying bricks is not exactly easy on labor.. And that would be the only small pile of bricks we've seen on the entire site.

It's paint/dye/powder to mark the spot of high radiation.
MiceAndMen
#8004
May23-11, 02:19 AM
P: 276
Quote Quote by westfield View Post
However, there are the SGTS ducts, HVAC ducts and others, who knows what the ducting system is in the pictures, who knows why tepco surveyed it and who knows why they showed it to us.
My second reply to this... I adjusted the levels a little on the second picture (the one to the south) just to enhance the contrast a bit. It's a little more complex up there than I initially thought. There seems to be a jib crane mounted on a vertical pivot that is probably used to load and unload equipment and fuel from vehicles. Other than that, it looks like a rat's nest of pipes and other things.
Attached Thumbnails
gamma_cam_2.jpg  
zapperzero
#8005
May23-11, 02:28 AM
P: 1,042
Quote Quote by Atomfritz View Post


(Edit 2: re-uploaded smaller sized pic, see full resolution pic here: http://imageshack.us/photo/my-images...actorstain.jpg )
I like your analysis. I think the red is red marker powder.
Let me throw my $0.02 in the rubble debate, from a very different angle.

I had been looking for a way to avoid having to think of burning concrete and burning metals, because I didn't understand why such high temperatures would not also produce other observable effects. Seems I found it.

The yellow stuff is indeed insulating foam. To be more precise, it is polyurethane foam, widely used for insulation and as a fire retardant. If you are looking for an explanation for what generated massive amounts of black smoke on several occasions, this may be it. A small electrical fire in a cable duct (a la Browns Ferry) can be enough to get it going.

Diablo Canyon incidents:
http://www.nrc.gov/reading-rm/doc-co...in88004s1.html

LATER EDIT: the small orange-brown pieces you ask about are also insulating foam. It gets like this from being exposed to UV light.
tsutsuji
#8006
May23-11, 02:35 AM
PF Gold
P: 1,220
Thanks for unearthing this Kyodo news.

Far greater amounts of radioactive iodine and cesium were found in rain, dust and particles in the air in some areas over a 24-hour period from Sunday morning due to rainfall, the science ministry said Monday.
http://english.kyodonews.jp/news/2011/03/80010.html
This blame-the-rain stance sort of rules out the possibility that any serious radiation was released into the air at the plant on March 20th or 21st.

Quote Quote by westfield View Post
In this case, are they simply surveying the place, or perhaps looking for a failure point or are they looking to see what equipment can be made serviceable?
I was thinking that at the very least by knowing where the hot spots are located they would know where they need to add shields to block the rays.
jlduh
#8007
May23-11, 02:44 AM
P: 468
Quote Quote by zapperzero View Post
Hey ho... when you say prism effects you mean the oddly coloured diffuse splotches in the water? What abot the two closely spaced shiny/white spots, violet on the edges, on the roof of #1 turbine hall? There's another similar one on the road in front of #4. Specular?
Concerning this particular picture that you mention:


I remarked when i saw it first when it was released by digitalglobe that there were those very bright spots encircled with coloured lines, especially on some roofs but also around the reactors on the ground. AT first i thought that these could be some glowing parts of fuel or corium emitting a very intense light, as in digital photography, this kind of fringing appears around very bright spots in an image, in fact this comes from an overflow of photos in the adjacent pixels when the pixels receiving too much light are saturating (which is called BLOOMING).

I tried to see on all the other pictures i saw after from the plant if i could do a correspondance between these spots seen on this picture taken just after explosion of N3 and some specific areas with remaining debris. In fact i didn't succeed in doing this: those spots didn't appear to me to be of special interest based on the later pictures.

So i don't know what to think. For sure these bright spots circled with color are surprising at first sight. On the other hand, we see in the sea area (on the same picture) that there are a lot of speculars coming from what looks to be like aluminum sheets reflecting in the sun. I don't know if there is something special on the water that makes it shining like that, or if it is just from the waves and the sun playing together (i think this second option is the good one). For sure, the picture is a little bit overexposed and the sun reflecting here and there doesn't help.

Now, even if the spots on the roofs for example are not "glowing corium" (which was not evidently) but reflections from shiny parts, we shoud find evidence of some of those parts on other pictures. I had a hard time to confirm this either... So i guess this needs maybe further look and analysis. But again maybe it's just speculars on some small shiny parts, we all know how bright this can be if just at the right angle!

Concerning the white dots in some pictures in areas with radioactivity: this is a different subject than above but to me this is clearly the effect of the radiations (gamma) on the sensor. This is very well shown in the experiment in the video posted. Some of these dots may be in fact dead pixels from a previous exposure (like in the experiment shown) or pixels reacting to some gamma rays i think.

CCDs are considered more proned to this than CMOS but CMOS are also vulnerable to this. There is a complete thesis available on this subject:

http://www.cse.yorku.ca/visor/pdf/MSc_thesis_Henok.pdf
Borek
#8008
May23-11, 02:55 AM
Admin
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P: 23,406
Quote Quote by Grumalg View Post
Maybe the brick color is due to Iodine? Iodine-129 @ .84% fission yield and 15.7 million year halflife could surely still be around in quantity.
Iodine is too volatile to stay in open place for that long. Besides this is not an iodine color.
zapperzero
#8009
May23-11, 02:57 AM
P: 1,042
Quote Quote by jlduh View Post
an overflow of photos in the adjacent pixels when the pixels receiving too much light are saturating (which is called BLOOMING).

Now, even if the spots on the roofs for example are not "glowing corium" but reflections from shiny parts, we should find evidence of some of those parts on other pictures. I had a hard time to confirm this either... So i guess this needs maybe further look and analysis.
Blooming on the edges, for sure. But I can't see what the mirror could have been either. I doubt anyone went on that roof to sweep away little blobs of corium though, after all, this is not as bad as Chernobyl, as they keep telling us :D
zapperzero
#8010
May23-11, 03:00 AM
P: 1,042
Quote Quote by tsutsuji View Post
This blame-the-rain stance sort of rules out the possibility that any serious radiation was released into the air at the plant on March 20th or 21st.
Serious amount of radiation in Tokyo is serious, no matter if it's from concentration due to rain or a new massive release.


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