Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[liamdavis]

EXTENT OF DAMAGE TO REACTOR BUILDINGS DUE TO EARTHQUAKE?


Have there been any reports of the extent and types of earthquake damage that occurred at other regional NPP's that didn't suffer catastrophic consequences of complete loss of power?

Perhaps this point was already made, but if so, I make it again. A 9.0 earthquake, in and of itself, could do significant damage to the reactor buildings. The scenarios I and others have considered in most detail follow the consequences of complete loss of all power and subsequent events related to the reactor vessels, primary containment, and spent fuel pools.

The chain of events at Fukushima with the rapid arrival of the tsunami and complete loss of power were such that, if done, there has been little or no reporting of a primary assessment of damages or likely damages due solely to the magnitude of the earthquake. Significant lateral thrusting occurred.

I am reminded of the external crack visible on Bldg 2 and must wonder if they are blast or earthquake-related, or more likely, a combination of both.

Also, in cross-section, the arrangement of a massive concrete and steel primary containment structure nested atop a huge underground torus leads me to wonder what damages the quake might have caused by the extreme forces of lateral thrusting where the two structures meet, so to speak.

Some knowledge of the specific types and locations of damages that might have been in play at Fukushima at the time power was lost would surely be helpful in sorting out what has followed.

According to this site, which keeps a running tally, as of my posting time there have been
851 quakes >4M
402 quakes >5M
51 quakes >6M
and 3 quakes >7M just since March 11, 2011.

http://www.japanquakemap.com/

By the time you go to the site it will have increased.

Over the 40 years of their operation how many quakes have the Daiichi plants endured? What ever the number it is remarkable. It may also have taken a toll that would have been very informative to analyze after decommissioning. What we cannot know is if those cumulative stresses brought some components too close to failure to withstand the latest combination of events.
liam

 

[timeasterday]

We could really do with a plan veiw of where the reactor is in relation to the cube. Yes if it's in the centre then I aggree but where you can see the green of possibly the crane... which is what I thought it was, there's an obvious hole been blown through everything. possibly the SFP being so heavily built. strong and deep it directed the hydrogen explosion in an upwards direction, piercing like a shaped charge and sending a bit of the roof up.?

Yeah, that could be what happened. I'm still a bit puzzled over the #3 explosion. In the video you can clearly see a large fireball come out of the south side (supposedly where the SFP is) and then it gets sucked back in before a large upward blast that seemed more centered in the building. In the photos the roof is pretty much gone over the north and south ends but still over the middle.

 

[TCups]

VISIBLE STRUCTURAL CRACKS IN SOUTH FACE OF BLDG 2, 4 - NOT CORRECT

I think your diagonal crack is where the stairs were ... look at building 2 in your first image there.

still examining these fascinating images!

#artax:

Oops. Must agree. Stairs. Shadows account for the apparent differences. Back to the drawing board, I guess. . .

SEE ATTACHED IMAGES:

 

[Joe Neubarth]

EXTENT OF DAMAGE TO REACTOR BUILDINGS DUE TO EARTHQUAKE?


Have there been any reports of the extent and types of earthquake damage that occurred at other regional NPP's that didn't suffer catastrophic consequences of complete loss of power?

Perhaps this point was already made, but if so, I make it again. A 9.0 earthquake, in and of itself, could do significant damage to the reactor buildings. The scenarios I and others have considered in most detail follow the consequences of complete loss of all power and subsequent events related to the reactor vessels, primary containment, and spent fuel pools.

The chain of events at Fukushima with the rapid arrival of the tsunami and complete loss of power were such that, if done, there has been little or no reporting of a primary assessment of damages or likely damages due solely to the magnitude of the earthquake. Significant lateral thrusting occurred.

I am reminded of the external crack visible on Bldg 2 and must wonder if they are blast or earthquake-related, or more likely, a combination of both.

Also, in cross-section, the arrangement of a massive concrete and steel primary containment structure nested atop a huge underground torus leads me to wonder what damages the quake might have caused by the extreme forces of lateral thrusting where the two structures meet, so to speak.

Some knowledge of the specific types and locations of damages that might have been in play at Fukushima at the time power was lost would surely be helpful in sorting out what has followed.

AT Fukushima the degree of shaking was not anywhere near a 9.0.

It might have been equivalent to a 6.0 or less.

 

[AntonL]

They need to take their samples out on the end of that rock and cement Quaywall extending to the right in the photo..

Looking at the swell action you can see the waves coming in at the bottom of the photo. That usually equates to water coming in from the ocean at that point. The absence of swells right at the plant effluent area suggests water flowing out to sea (path of least resistance. I'm an avid body surfer and know how to look for rip currents.) I am willing to bet that their strongest radioactive contamination will be along that quaywall

Joe you 100% correct , a rip will be set up along the breakwater due to the swell action, the sampling point is such as not to expose the sampler unnecessarily to radiation, you can actually see a track leading down to the beach on the land side. Any way nobody will be body-surfing there for a very very long time, cesium being heavy will settle and embed itself into the moving sand

Body surfing, reading the waves and staying safe in a ocean with 3 meter plus waves is also one of my specialties

 

[jlduh]

Concerning the Tcups remark about the possible weak point being at the junction between the torus and the "pear" vessel, especially if you consider the necessity to "float" to some extent for resisting to quakes, as a mechanical engineer i must admit that for me, as i feel it, there is probably a weak point at the radial pipes connecting the torus and the vessel.

The way this design works, which has to be at the same time floating (to be resilient) and very rigid because of the mass of concrete around the vessel to make it resistent from the containment standpoint, is not clear for me...

I saw on several drawings that the torus sits on some strange supports (like fins below it) and I'm wondering if this would be to allow for some movement of it in case of quake? Also i see on this sketch some parts (orange) at the middle of the pipes joining the vessel and the torus: are these some kind of "joints" allowing for some kind of expansion or relative movement?
http://www.netimago.com/image_184623.html

We see these kind of "articulated" joints (or thermal expansion joints) on this picture:

http://i700.photobucket.com/albums/ww1/indoorcarnivore/Browns_Ferry_Unit_1_under_construction.jpg

Something to consider, maybe it has been documented in the past studies, and maybe that was one of the reasons to get rid of the torus in newer designs...

I've seen written that the concerns where about loads at the suppression chamber that were not taken into account in the first design, but it was more about thermodynamic loads it seems (when transient spikes happen in terms of temperature and pressure), that's why they added elements in the SP to diminish the size of the steam bubbles and so the loads. Don't know about the quake loads.

I think you saw this info some days ago, from IAEA revealed by wikileaks:
http://www.indianexpress.com/news/iaea-warned-japan-over-nuclear-quake-risk-wikileaks/763709/

An other remark on the black and white picture above showing the pressure vessel and the torus being built: many many pipes going out of the containment vessel, this is also a weak design from this standpoint.

A different subject with an other confirmation on this plot: the core pressure in reactor N°1 continues to rise dangerously...

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/v6/plot-un1-full.png

 

[TCups]

DO WE KNOW THE FORCE OF THE EARTHQUAKE AND EXTENT OF POSSIBLE DAMAGES TO THE FUKUSHIMA SITE BEFORE THE TSUNAMI?

AT Fukushima the degree of shaking was not anywhere near a 9.0.

It might have been equivalent to a 6.0 or less.

Really? References? It would help to know for sure.

6.0 vs 9.0 would certainly have been one helluva difference - what? a factor of 32 for each full point on the Richter scale, correct? or 1024X less powerful at the Fukishima site than the reported 9.0 quake at the epicenter. Maybe.

Is the magnitude on the Richter scale related to the total duration of the quake event? That is, does a "6.0 quake" that lasts for 2 full minutes instead of 30 seconds measure higher on the Richter scale?

Does anyone know what the quake-resistant structure of a NPP might be? It doesn't appear to be a floating slab foundation at first glance.

Is complete loss of the primary power grid and water sloshing out of the SFP in large quantities, dousing one of the workers (as per his first hand account) common in a 6.0 quake? If not, what brought down the power lines or power before the tsunami hit? Didn't I read that the shore line had shifted almost a meter after the quake in some places along the coast?

 

[AntonL]

AT Fukushima the degree of shaking was not anywhere near a 9.0.

It might have been equivalent to a 6.0 or less.

I read somewhere actually around 7 for the site

but https://www.physicsforums.com/showpost.php?p=3218366&postcount=1989"

so the horizontal acceleration due the earthquake at Daiichi was 507 gal, 1 gal being 1 cm/s^2 that means an acceleration of 5m/s^2. That is a lot.

 

[Joe Neubarth]

DO WE KNOW THE FORCE OF THE EARTHQUAKE AND EXTENT OF POSSIBLE DAMAGES TO THE FUKUSHIMA SITE BEFORE THE TSUNAMI?



Really? References? It would help to know for sure.

6.0 vs 9.0 would certainly have been one helluva difference - what? a factor of 32 for each full point on the Richter scale, correct? or 1024X less powerful at the Fukishima site than the reported 9.0 quake at the epicenter. Maybe.

Does anyone know what the quake-resistant structure of a NPP might be? It doesn't appear to be a floating slab foundation at first glance.

Is complete loss of the primary power grid and water sloshing out of the SFP in large quantities, dousing one of the workers (as per his first hand account) common in a 6.0 quake? If not, what brought down the power lines or power before the tsunami hit? Didn't I read that the shore line had shifted almost a meter after the quake in some places along the coast?

T, I live in southern California. I have been through hundreds and hundreds of 5.0 earthquakes just a hundred miles away that I could not even feel. Distance definitely dampens the effect. Now, if a building is built upon fill or soft soil (clay and water) a building fifty miles from the quake can rock and roll and collapse if it is not structurally sound.

A 5.0 earthquake can bring down power lines if it unleashes boulders from a hillside and they take out the electrical grid transmission tower. Anything like that can happen.

The biggest issue, of course in Japan was that their grid fell apart with all of the nuclear power plants on the north side of that large island going to shutdown mode (SCRAMS) during a part of the day when demand was high. Circuit breakers open and whole regions are without power.

 

[TCups]

T, I live in southern California. I have been through hundreds and hundreds of 5.0 earthquakes just a hundred miles away that I could not even feel. Distance definitely dampens the effect. Now, if a building is built upon fill or soft soil (clay and water) a building fifty miles from the quake can rock and roll and collapse if it is not structurally sound.

A 5.0 earthquake can bring down power lines if it unleashes boulders from a hillside and they take out the electrical grid transmission tower. Anything like that can happen.

The biggest issue, of course in Japan was that their grid fell apart with all of the nuclear power plants on the north side of that large island going to shutdown mode (SCRAMS) during a part of the day when demand was high. Circuit breakers open and whole regions are without power.

J:
I lived in Cape Giradeau, MO for 13 years near the epicenter of the New Madrid fault. The fault lines on the west coast of North America, particularly in California, are in a geographic region where the substructure is basically crushed rock. Like Japan, I believe, the fault line is a subduction zone with the Pacific plate diving under the NA Plate. Major earthquakes on the west coast don't have linear propagation of energy for long distances. On the other hand, major earthquakes along the New Madrid Fault are on a substructure of granite, and the fault line is along abutting plates. When they break loose, like in the early 1800, quakes in Missouri rang church bells in Philadelphia. An 8.0 in New Madrid would be an 8.0 in Memphis and St. Louis. I don't know that you can draw the conclusion that the force of the quake was diminished at Fukushima, but in any case, the hard data would be good to know.

You are of course correct about the probable reasons for loss of power.

 

[DSamsom]

Hi, new in this very useful forum.

Can somebody help me understanding what is happening in reactor 1 these days/hours. The Temperature dropped a little, but the core pressure keeps rising. What could be the explanation?

 

[Reno Deano]

Some information on TMI Upgrades that Units 1, 2, 3, and 4 should have implemented by TEPCO. There is no reason or information that they did not implement these modifications. This data can give insight to reasons for the uncontrolled hydrogen releases and why reactor vessel water levels could not be ascertained after the Station Blackout hit.

From NUREG-0737, POST-TMI REQUIREMENTS FOR OPERATING REACTORS

http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0737/final/sr0737.pdf"

These requirements cover, among other things, RPV and Containment relief valves, hydrogen gases control, reactor water level determination, high range radiation monitors in-plant and quantative radiochecmistry analysis off reactor coolants, auxillary feed water system improvements, reactor containment isolation, back up emergency AC and Battery power for possible Station Black Out conditions, etc. Due to the plants experiencing a prolonged Station Blackout, most of the system failed safe.

Excerpt from Table of Contents:

II.F.2 Instrumentation for
detection of
inadequate core
cooling

II.F.1 Accident-monitoring
1. Noble gas monitor
2. Iodine/particulate sampling
3. Containment high-range monitor

II.F.2 Instrumentation for detection of
inadequate core cooling
4. Containment pressure
5. Containment water level
6. Containment hydrogen

 

[Joe Neubarth]

Hi, new in this very useful forum.

Can somebody help me understanding what is happening in reactor 1 these days/hours. The Temperature dropped a little, but the core pressure keeps rising. What could be the explanation?

They are pumping more water in.

 

[curious11]

Sorry if this subject has already been put to bed. I thought I'd use the latest hi-res images to locate the position of the suspected sf-rods from an earlier video.

So, here they are. Any idea what the feature hi-lighted might be?

 

[artax]

Hi, new in this very useful forum.

Can somebody help me understanding what is happening in reactor 1 these days/hours. The Temperature dropped a little, but the core pressure keeps rising. What could be the explanation?

No Idea, How much has the pressure increased or how quickly is it rising, and where are they measuring it... the last I heard (Wiki) they thought 1,2 and 3 had cracks in the containment, or was it the pressure vessel I just read.
Anyone know how high the reactor buildings are...(were!) I want to work out how high that concrete went in the blast at number 3.

 

[jensjakob]

TCups, I can't find the "fuelrods" on the new hi-res images...

Can you?

If they are gone, someone knows what they were...

I have now . . . Here are some enhanced stills from the video.

 

[artax]

Sorry if this subject has already been put to bed. I thought I'd use the latest hi-res images to locate the position of the suspected sf-rods from an earlier video.

So, here they are. Any idea what the feature hi-lighted might be?

https://www.physicsforums.com/attachment.php?attachmentid=33787&stc=1&d=1301584597

Well we've sort of come to the conclusion that all four buildings have the Spent Fuel Pool at the south side of the building/reactor. So if that's true I don't know what those rods are as they are on the North side... but they sure look like the way they were described on Radio 4 last week, about as thick as your finger and 4 meters long!
So maybe they had so many they were storing them everywhere in the less robust tanks around the place. It seems the Americans and no doubt many countries are just saving them up for a rainy day!
It's a shame they can't just hand them out to housholds to chuck in the bath when you need some hot water!

 

[Borek]

So, here they are. Any idea what the feature hi-lighted might be?

Fits our latest photography competition perfectly.

Looks like a pipe to me. Tons of pipes around.

 

[curious11]

Well we've sort of come to the conclusion that all four buildings have the Spent Fuel Pool at the south side of the building/reactor. So if that's true I don't know what those rods are as they are on the North side... but they sure look like the way they were described on Radio 4 last week, about as thick as your finger and 4 meters long!
So maybe they had so many they were storing them everywhere in the less robust tanks around the place. It seems the Americans and no doubt many countries are just saving them up for a rainy day!
It's a shame they can't just hand them out to housholds to chuck in the bath when you need some hot water!

Well they certainly aren't near the sfp. Do we have a schematic to overlay on this aerial photo? Maybe they're other elements used to space-out/organise the actual rods; ie benign?

 

[artax]

@ Jenskabob, I'm pretty sure curious ! has located the place... they're just too small to see.

 

[artax]

Well they certainly aren't near the sfp. Do we have a schematic to overlay on this aerial photo? Maybe they're other elements used to space-out/organise the actual rods; ie benign?

I've been searching all day for an overhead plan of one of these reactors with the different floors schematicked. (if that's a word)
I still think it's likely that they had loads of 'FAIRLY COLD' rods that they just thought they'd store in the nearest pool of water, I mean no-one's going to know... unless there's a massive Tsunami next week!
You know what industry is like.

 

[83729780]

http://lewis.armscontrolwonk.com/files/2011/03/Cause_of_the_high_Cl38_Radioactivity.pdf"

Conclusions

So we are left with the uncomfortable realization that the cause of the Cl-38 concentrations is not due to seawater
intercepting neutrons from natural spontaneous fission of the used nuclear fuel. There has to be another reason.

Assuming that the TEPCO measurements are correct, the results of this analysis seem to indicate that we cannot
discount the possibility that there was another strong neutron source during the time that the workers were sending
seawater into the core of reactor #1. However, since we don’t know the details of the configuration of the core
and how the seawater came in contact with the fuel it is difficult to be certain. Given these uncertainties
it is nonetheless important for TEPCO to be aware of the possibility of transient criticalities when work is being done;
otherwise workers would be in considerably greater danger than they already are when trying to working to contain
the situation. A transient criticality could explain the observed 13 “neutron beams” reported by Kyodo news agency
(see above). This analysis is not a definitive proof but it does mean that we cannot rule localized criticality out
and the workers should take the necessary precautions.

 

[artax]

very interesting link thanks.
Will have to read it tomorrow.

 

[curious11]

I've been searching all day for an overhead plan of one of these reactors with the different floors schematicked. (if that's a word)
I still think it's likely that they had loads of 'FAIRLY COLD' rods that they just thought they'd store in the nearest pool of water, I mean no-one's going to know... unless there's a massive Tsunami next week!
You know what industry is like.

Or. they;re just control rods... ?

http://www.sciencephoto.com/images/download_lo_res.html?id=841700465"

 

[gmax137]

TCups, I can't find the "fuelrods" on the new hi-res images...

Can you?

If they are gone, someone knows what they were...

That looks like a bunch of 3/8 inch stainless tubing to me. There's typically miles of that stuff in a plant, used for instrumentation.

 

[TCups]

Sorry if this subject has already been put to bed. I thought I'd use the latest hi-res images to locate the position of the suspected sf-rods from an earlier video.

So, here they are. Any idea what the feature hi-lighted might be?

https://www.physicsforums.com/attachment.php?attachmentid=33787&stc=1&d=1301584597

@Curious

You have indeed located the rod-like objects in the latest areal imagery. This was taken from the first helicopter fly over, and by way of disclosure, "Photoshop'ed" to correct color levels, contrast, and sharpness

http://i306.photobucket.com/albums/nn270/tcups/903a9527.jpg

And here is my best SWAG at the layout of the top floor, see post #2089

https://www.physicsforums.com/attachment.php?attachmentid=33731&d=1301513587

which puts the "rod-like structures west of the location of the equipment pool, I believe. I am not sure of the confirmation of my layout in the second image, however.

That looks like a bunch of 3/8 inch stainless tubing to me. There's typically miles of that stuff in a plant, used for instrumentation.

Yes, but not anywhere else in a fairly tight cluster that I can see. And in the midst of explosive destruction, they seem awfully rigid -- not bent like lots of the rebar seen in other images.

 

[TCups]

T, I live in southern California. I have been through hundreds and hundreds of 5.0 earthquakes just a hundred miles away that I could not even feel. Distance definitely dampens the effect. Now, if a building is built upon fill or soft soil (clay and water) a building fifty miles from the quake can rock and roll and collapse if it is not structurally sound.

A 5.0 earthquake can bring down power lines if it unleashes boulders from a hillside and they take out the electrical grid transmission tower. Anything like that can happen.

The biggest issue, of course in Japan was that their grid fell apart with all of the nuclear power plants on the north side of that large island going to shutdown mode (SCRAMS) during a part of the day when demand was high. Circuit breakers open and whole regions are without power.

Joe:

I draw your attention to Astronuc's earlier post at 1989. At the time, I was not smart enough to understand what Astronuc was telling us. The lateral acceleration recorded at unit 3 exceeded the design maximum for lateral ground motion acceleration in the east-west axis, ie, in the direction of propagation of the energy from the epicenter of the quake.

Quoting in part, from Astronuc's reference source:

"At Daiichi there is still no data for units 1, 2 and 5, but available figures put the maximum acceleration as 507 gal from east to west at unit 3. The design basis for this was 441 gal. Other readings were below design basis, although east-west readings at unit 6 of 431 gal approached the design basis of 448 gal."

I am also informed that 1 gal = 1 cm/sec² and 500 gal = 1 m/sec²

I've been wondering about the ground motion and accelerations. Apparently not all the data are collected and/or processed, but from WNN,

http://www.world-nuclear-news.org/RS_Fukushima_faced_14-metre_tsunami_2303113.html

No mention of unit 4.

From - http://www.world-nuclear.org/info/inf18.html

 

[jlduh]

Thanks FRED for these excellent quality pictures, taken it seems the 20th and the 24 th of March by a Canon KissX4 (which is in fact the 550D in Japan) and a Canon 5D MarkII (based on the exifs of the pictures... i practice photography so it's an habit to check that).

I guess these are the ones take by the Japanese Air Service in Nigata with the small plane used also for volcanoes. Where did you find them by the way?

As everybody i started to review them in detail. On buiding 3, i have something which ressembles to the cover of the pressure vessel, on this capture:

http://www.netimago.com/image_184641.html

extracted from this full res image:

http://www.netimago.com/image_184667.html

Do you see this big yellow round part which is right behind the pillar n°4, right in the middle of the building from this view taken from the East side?

I've been at first in favor of the theory of the concrete plus being ejected by the huge vertical explosion, but looking at the top and at the way the explosions precisely happened on the video, I rejected this idea. Now i see this picture and I wondering what this part is, right here...

And then, where would have gone the big concrete plug? Just moved sideways maybe?

I'm in the position of really saying that there hasn't been big ejections at the vertical of this point above the reactor well. But maybe displacement?

Could it be that there may be a second cover that was on the top floor for maintenance reasons for example?

 

[Joe Neubarth]

http://lewis.armscontrolwonk.com/files/2011/03/Cause_of_the_high_Cl38_Radioactivity.pdf"

Some time ago I brought up the issue of injecting sea water into the reactor for cooling sake. At that time all of the articles that I read (perhaps fifty or sixty) mentioned injection of sea water into the core and never mentioned boron treatment. Our moderator was kind enough to copy several that were available to him. Obviously, he was reading the right articles. Then I noticed a post with the boron information struck through and then an article that said they injected the boron AFTER the sea water.

If so I am quite certain they managed to flush enough boron from the reactor so as to ensure an increase in the thermal neutrons available for fission, and probably created a temporary (transient) criticality in the high energy pulsating blob that used to be the reactor core.

There is no way of knowing, of course, short of data telemetry that would have recorded the increase in all types of radiation at the scene near the time they were injecting sea water that was not already mixed with boron. That most certainly will account for the oddities associated with Reactor One.

 

[rmattila]

We've been taking some air samples here in Finland, with preliminary results suggesting Cs-134/137 activity ratios of the order of 1,05. Having no idea of what kind of core design they are using at Fukushima, we made some rough calculations of isotopic concentrations of "typical" BWR assembly at different void histories (see example below).

What we're hoping is to try to see, if it would be possible to estimate the extent of core damage based on isotopic ratios of nuclides from different samples. Like, if it would seem that the measured isotopic ratios correspond to the void history in the top of the core rather than the core average, or the burnup in the most powerful assemblies vs. core average etc.

I wonder if anybody else is doing anything similar, and if someone would have better information on the fuel/reload strategy used in the accident reactors.

 

[AntonL]

Joe:

I
I am also informed that 1 gal = 1 cm/sec² and 500 gal = 1 m/sec²

PLEASE EDIT your post

1 gal = 1cm.sec^2
500 gal = 5 m/sec^2

then I delete this message

 

[Joe Neubarth]

That looks like a bunch of 3/8 inch stainless tubing to me. There's typically miles of that stuff in a plant, used for instrumentation.

It does not to me.

I see rumpled elongated narrow sheets that were made that way by physical shock, like from that explosion.
They appear to be (approximate guess) ten times to fifteen times wider than they are thick.
For them to have taken on such a rumpled shape their substance must have some malleability, much like lead.
What ever fits that description is what it is.

I think they are fuel rods that have been through one hell of an explosion.But what the hell, I am not a nuclear engineer. I just go by what my eyes tell me.

 

[jlduh]

I post here a series of screenshots of the video showing the explosion of reactor 3. Take the stack vent (the white "antenna") as a reference, it is perfectly aligned with the left edge of the reactor N°3 building.

http://www.netimago.com/image_184705.html

Ok,

FIRST EXPLOSION or FIRST TWO EXPLOSIONS?

a) BIG ORANGE FLASH AT THE LEFT SIDE TOP OF THE REACTOR. This is South side. So it starts with probably an H2 explosion in the top rop, close to SFP.

b) BIG DARK GREY BURST ON THE LEFT SIDE OF THE BUILDING (North)
http://www.netimago.com/image_184715.html

AND THEN (SAME EXPLOSION OR A SECOND OR THIRD ONE?) BIG VERTICAL DARK GREY BURST EMERGING VERY CLOSE TO THE REFERENCE "ANTENNA" (then it moves parallel to the right of course because of the wind), SO MORE ON THE LEFT SIZE OF THE BUILDING (NORTH)

http://www.netimago.com/image_184724.html

Then the vertical grey burst continues to rise very high in the sky (i estimated at around 500m based on the fact that the reactor buiding is around 50 meters high). But it's difficult to see where are the big chunks at the top.

http://www.netimago.com/image_184731.html

http://www.netimago.com/image_184733.html

For reference the complete video is here:


I put also the Hi Res pic from the top of the reactor to try to correlate what the explosion says with what the debris can say:

TOP VIEW: (North is right side, South left side)

http://www.netimago.com/image_184741.html

FROM WEST TOWARDS EAST (North on the left side, South at right)
http://www.netimago.com/image_184742.html

FROM EAST TOWARDS WEST (South on the left side, North at right)

http://www.netimago.com/image_184743.html

PERSONAL CONCLUSIONS: to me pictures of the debris correlate with pictures of the explosions (what a scoop hey!). On the south side at the top we see the place of the first flash above the pool, with a big hole and around the metal is heavily bent. On the North west side, this has been the place of the big vertical burst: heavy destruction of the building, with some holes still visible from the bottom. The metal structure of the roof which stays in the middle seems to have been displaced towards the south by the vertical burst. The south side of reactor n°2 has been crippled by the lateral debris projected by the lateral burst on the North side at N°3. We can also see that Building n°3 is more heavily damaged on its west side than on its east side (one level more still there).

 

[Maxion]

I think you guys will like this.

High-res satelite/air photographeis of the reactors.

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

 

[TCups]

I post here a series of screenshots of the video showing the explosion of reactor 3. Take the stack vent (the white "antenna") as a reference, it is perfectly aligned with the left edge of the reactor N°3 building.

jlduh:
Sorry sir. The thumbnails you post, at least on my browser, are not linked to the full resolution images. All I am getting is thumbnail views.