Japan Earthquake: nuclear plants

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.

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.

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.

Yes, this really disturbs me.
And a closer looking also makes me doubt that this is just dye.
See this zoomed-in image.

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.

According to Lochbaum, workers at Brunswick-2,
which also has the Mark I containment — a design by
General Electric used at units 1, 2 and 3 at Fukushima
I — performed “a structural integrity test on the reactor”
in the 1970s, in order “to satisfy a requirement in the
American Society of Mechanical Engineers (ASME) code
for prototype containment designs.”
Progress says the test is required of all containments
before reactors enter service.
He said workers pumped air into the containment
vessel to raise the pressure inside beyond the designed
maximum of 62 pounds per square inch to 71 psi, but
that the pressure stayed constant at 70 psi. “A hissing
sound attracted workers to the top of the containment
structure,” said Lochbaum. Workers discovered that the
air pushed up the metal containment head, which is
bolted to the containment wall “with a rubber O-ring
between the surfaces,” and seeped out into the refueling
cavity above the primary containment, he said.
“It is possible that the containment pressures [at
Fukushima I units] rose high enough to replicate the
Brunswick experience,” he said.
But while containment leakage in the Brunswick test prevented
the pressure inside from rising above 70 psi, Japan’s
NISA reported that pressure in the containment of unit 1
at Fukushima I had exceeded 120 psi a day after the reactor
had lost cooling. Tepco reported that the containment vessel
pressure at unit 2 had reached above 102 psi.

Ventilation system
As steam accumulated and pressure rose in the containment
vessels, Tepco released some steam outside the reactor
buildings at all three units. Helwig said it is possible that
some steam mixed with hydrogen had escaped into the reactor
building during the venting.
The original Mark I design came with a so-called standby
gas treatment system, or SGTS, to vent steam under emergency
situations. Such a system first scrubs most radioactive
particles out of the steam through filters and then releases it
through the ventilation stack to the atmosphere. Fukushima
I units 1, 2 and 3 are still equipped with the SGTS system,
said a Tepco official, who requested anonymity because he is
not authorized to speak to the press.
The SGTS uses ductwork, which is susceptible to leaking
because it is not air tight and is not designed to withstand
significant pressures, to channel steam, said Helwig.
NRC in the 1980s requested that all US plants with Mark
I containments install hardened vents, replacing ductwork
with hard pipes, according to a March 19 report on the Mark
I by GE Hitachi, the company that combined the nuclear
operations of GE and Hitachi.
Borchardt told NRC commissioners that all US Mark I
reactors now have hardened vents, which he said would not
allow hydrogen to leak during venting.
Alexander Marion, vice president of nuclear operations
for NEI, said in an interview March 22 that US industry
experts assume that Fukushima I reactors do not have hardened
vents, “because somehow they were releasing hydrogen
into the secondary containment, but we just don’t know.”
The Tepco official, who answered questions through
emails, however, said the ductwork SGTS was not used at
Fukushima I for venting, “because the pressure of the containment
vessel was high.” Instead, he said, the company
used an alternative vent called the direct release line, which
can withstand high pressure, to blow off steam and cut
pressure inside the containments. “The direct vent line we
used this time is hardened pipe designed for severe accident
case,” he said.

Please, not a "what this pixel is" again.

Color that you see depends on the light at the place picture was taken, white balance of the camera and color temperature of your monitor (and other things). In some cases original colors are irreproducible on the screen no matter how you try, in some cases they are changed beyond recognition. So while there is some reddish tint in this place, it accurate shade is questionable.

Shapes do look "brickish" but if you desaturate the image (making it black and white) they no longer look like bricks, just like a random rubble. It is combination of shape and color that tricks you into thinking about bricks.

I like the idea of a paint bomb.

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 N°3 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

There are many different kinds of things which cause fringing. There are optical defects that are present in the lens, different sensor types might cause fringing (e.g Blooming, which is only present in CCD sensors).


The "fringin" on the highlights in the photo is with 99% certancy an optical effect caused by the earths atmosphere coupled with the extreme optics needed to get images like this from earth orbit. There's no WAY that radiation could cause this. Also if the highlights weren't reflections of sunlight then the light source that produced them has to be as bright or brighter than the sun. And that would be kind-of noticeable on the ground.

interesting figures. The 500 mSv however could be misleading. The title of the map is "organ dose of I-131". Assuming they mean the organ thyroid gland, which has a weighting-factor of 0,05, the resulting effective dose would be 25 mSv.

Hello jpquantin,
As you have calculated the loss rates of SFP 4 is it possible that the SFP 4 at some point has overflowed?
When they spray water over the SFP is there any mechanism that prevents it from overflowing except "let's stop the pumps"?

This. From the live feed. No zooming and no cropping on my part.

Attachment 35798

EDIT: also, this
Attachment 35805

More detailed analysis of accumulated turbine building water from march sampling finally published:

http://www.tepco.co.jp/en/nu/fukushi...10522_04-e.pdf

Any comments?

Is it possible to locate the seawater pumps of Fukushima Daiichi precisely on satellite views or on the map at http://www.tepco.co.jp/en/nu/fukushi...20110323-e.pdf ? According to http://www.yomiuri.co.jp/dy/national/T110410003477.htm they are "near water intake outlets". According to http://www.asahi.com/english/TKY201104060126.html they were "not located within a sealed structure" and had been designed at a time prior Hitachi and Toshiba gained the experience that would lead them to locate seawater pumps "within buildings".

More detailed analysis of accumulated turbine building water from march sampling finally published:

http://www.tepco.co.jp/en/nu/fukushi...10522_04-e.pdf

Any comments?