Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[MadderDoc]

Page 93 of those DAEC drawings has a sketch, albeit not detailed, of that deck.

This sketch is more like the deck of the Fukushima reactors no.2-4:

I am curious how main steam piping is routed out of vessel and where are safety valves relative to your steam plumes.. for they don't quite line up with those passageways to pools.
The DAEC drawing pages 4 and 5 is so crowded it's hard to read.

I am not sure one can necessarily conclude much from the position of the hotspots. There is a leaking PCV down there under several meters of more or less cracked up concrete shield and the steam leaking out likely just take the easiest way out. There could also be weird chimney effects.

ps. jim, please check your method of quoting/replying (are you using the quote button?) The title of the sub-thread seems to be reset to the title of the main thread when you reply.
pss. I found the constantan wire, cheers :-)

 

[MadderDoc]

Building soundness testing (was Re: ..

An English pdf is provided on the same date on the same topic, but the contents, although overlapping for some part, are not the same:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120516_05-e.pdf Soundness Verification of Unit 4 Reactor Building at Fukushima Daiichi Nuclear Power Station (9 pages only)

tsutsuji, the 9 pages English version mentions a method for tilt/skew testing applied to the walls of the buildings, the Japanese version does not seem to mention it. Have you encountered any results of the soundness testing using that method?

 

[tsutsuji]

tsutsuji, the 9 pages English version mentions a method for tilt/skew testing applied to the walls of the buildings, the Japanese version does not seem to mention it. Have you encountered any results of the soundness testing using that method?

I had not realized that there were actually two Japanese pdfs about unit 4's reactor building. So I edited my previous post adding:

Edit: The English pdf mentioned above is a translation of yet another Japanese pdf, that one : http://www.tepco.co.jp/nu/fukushima-np/images/handouts_120516_06-j.pdf (9 pages)

I think it is the first time that I hear about testing the walls that way.

I also found the following press release in the "Important report from Tepco" section of their website:

http://www.tepco.co.jp/en/nu/fukushima-np/info/images/120426_01-e.pdf "We affirm that the Reactor Building and Spent Fuel Pool of Unit 4 will not collapse in the event of an earthquake" (dated 26 April 2012) where they talk about their plan to use "non-destructive inspection" such as Schmidt hammer.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120515_02-e.pdf "May 14: While installing the data logger (data collection equipment used to measure the direct current resistance of thermometer in Unit 1), we found that the wiring for safety valve 4B thermometer (TE-261-13B) and safety valve 4C thermometer (TE-261-13C) connected to the digital recorder in PCV was done in a opposite manner. At 7:12 PM on the same day, the connection was redone properly. The cause of this miswiring is currently being investigated. These temperatures are not included in the monitoring list of the technical specification (Article 138 and 143)."

 

[NUCENG]

Page 93 of those DAEC drawings has a sketch, albeit not detailed, of that deck.

The passage way to dryer pool is as you'd expect wider than the one to SFP.

I couldn't make a lot out of trying to overlay them mentally.

I am curious how main steam piping is routed out of vessel and where are safety valves relative to your steam plumes.. for they don't quite line up with those passageways to pools.
The DAEC drawing pages 4 and 5 is so crowded it's hard to read.

Main steam piping exits the vessel below the RPV Head flange. The piping nozzlkes are spaced 90 degrees apart and are then routed down to the first floor and become parallel as they exit the drywell to the steam tunnel to the turbine building. One set of MSIVs (inboard) are located inside the drywell and the second outboard MSIVs are in the steam tunnel.

Safety and relief valves are on the main steam piping near the vesssel. Most of them have piped discharge to the torus. Some BWRs have unpiped safety valves that discharge to the drywell, but these are the valves with the highest relief pressure setpoints. From what I have read the Safety Relefs Valves that were opened were probably all piped to the torus.

 

[jim hardy]

main steam piping

Main steam piping exits the vessel below the RPV Head flange. The piping nozzlkes are spaced 90 degrees apart and are then routed down to the first floor and become parallel as they exit the drywell to the steam tunnel to the turbine building. One set of MSIVs (inboard) are located inside the drywell and the second outboard MSIVs are in the steam tunnel.

Safety and relief valves are on the main steam piping near the vesssel. Most of them have piped discharge to the torus. Some BWRs have unpiped safety valves that discharge to the drywell, but these are the valves with the highest relief pressure setpoints. From what I have read the Safety Relefs Valves that were opened were probably all piped to the torus.

Thanks Nuceng

so they'd all have to be inside drywell (or PCV whichever's right name...) i assume they're up high, very near the vessel penetrations?

Thaks MD, note title block :) :)

 

[MadderDoc]

Miswired sensors (was.. Building soundness..)

<..>
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120515_02-e.pdf "May 14: While installing the data logger (data collection equipment used to measure the direct current resistance of thermometer in Unit 1), we found that the wiring for safety valve 4B thermometer (TE-261-13B) and safety valve 4C thermometer (TE-261-13C) connected to the digital recorder in PCV was done in a opposite manner. At 7:12 PM on the same day, the connection was redone properly. The cause of this miswiring is currently being investigated. These temperatures are not included in the monitoring list of the technical specification (Article 138 and 143)."

Looking up in the latest reliability testing from May 1st, all that can be seen is that -- compared to the other two TE-261-13's -- TE-261-13A has returned clearly higher readings, and appears to be more sensitive to temperature change. This is not quite what I'd expected to see, but perhaps there's something I am missing.

I interpret Tepco's explanation that 'the wiring for safety valve 4B thermometer (TE-261-13B) and safety valve 4C thermometer (TE-261-13C) connected to the digital recorder in PCV was done in a opposite manner' to mean both of the sensors had been connected with reversed polarity, whereas TE-261-13A has been connected correctly.

This is not the first time we hear about miswired sensors.

 

[MadderDoc]

I think it is the first time that I hear about testing the walls that way.

Measuring the verticality of the walls would seem to be suitable to answer the valid question whether the building has been flexed to the side, something which the water level measurements in the reactor well and the SFP might not be able to detect.

 

[tsutsuji]

I interpret Tepco's explanation that 'the wiring for safety valve 4B thermometer (TE-261-13B) and safety valve 4C thermometer (TE-261-13C) connected to the digital recorder in PCV was done in a opposite manner' to mean both of the sensors had been connected with reversed polarity, whereas TE-261-13A has been connected correctly.

I think they mean that the TE-261-13C thermocouple was connected to the TE-261-13B digital recorder and vice versa.

 

[jim hardy]

pss. I found the constantan wire, cheers :-)

put some water in a coffee cup and stick the two wires in it. Observe voltage when they're touching vs separated. A few grains of salt will help your water conduct the current necessary to drive your meter. Then try constantan vs a galvanized nail, a strip of aluminum foil, an iron paperclip, and of course a piece of copper wire..

Cheers also !

old jim

 

[MadderDoc]

I think they mean that the TE-261-13C thermocouple was connected to the TE-261-13B digital recorder and vice versa.

Yes, thank you, that must be it. I can see the switch back to correct on May 14 has now left a discontinuity in the 6 hour data series for those two sensors. I suppose Tepco will have logs to determine when the incorrect connection has been done, and so retrospectively will be able to correct the designation of the data. There is no other obvious discontinuity to be seen in data as far as it goes back in time, so the faulty connection would have happened either before that, or at a time when the two sensors returned similar readings.

 

[MadderDoc]

Of most considerable interest is the area around the gate to the equipment pool. It was this area of the building, which had
- the public's eye intently kept focused away from it,
- the hottest hotspots by far,
- the massive north major twin plume from the building originating from it, and was
- the likely source point of the black 'this is not styrofoam' smoke events of March 21st and March 23rd.

To the March 20th thermographic overlay of the 5th floor above, I have inserted a photo-detail, which shows
how the equipment pool gate area appeared from a crane camera much later, by the end of August 2011.
Emission from the cracks at the sides of the equipment pool gate was still ongoing, but had by then been reduced to a trickle
compared to its heydays during March, April, and May.

 

[jim hardy]

your photos of upper deck & steam leaks

i think this is same area March 16. Cryptome photo 47, cropped a bit.
Looking West, and the column is #4 the centerline of building.

That crane picture you posted is closest to high resolution I've seen of that locale.

 

[MadderDoc]

There are no published photos of the top of unit 3 that are suitable to produce a complete thermographic overlay from.
This is probably as good as it gets at the current level of BO.
Green-yellow-orange to red represent areas above the building top which are at a significantly higher temperature than ambient.
The efficiency of IR blocking by the huge fallen overhead steel crane across the reactor areas is well demonstrated.
http://www.gyldengrisgaard.eu/fuku_docs/111008_05enhovl_thumb.jpg

http://www.gyldengrisgaard.eu/fuku_docs/111008_05enhovl.jpg and the http://www.gyldengrisgaard.eu/fuku_docs/111008_05enh.jpg on which the overlay was made,
enhanced from the original photo released by Tepco

 

[jim hardy]

There are no published photos of the top of unit 3 that are suitable to produce a complete thermographic overlay from.
This is probably as good as it gets at the current level of BO.
...

The efficiency of IR blocking by the huge fallen overhead steel crane across the reactor areas is well demonstrated.

I am carrying as an open question whether that crane was always in just that spot.
The dark circle in that Cryptome #47 shows in early helicopter videos pre- 24 March
but not in later photos or videos
my circles aren't perfectly aligned , sorry

... later ............... 3/16 ...

i don't know whether to dismiss it as an artifact of lighting.
In march the sun still comes up somewhat to North lighting from right side of photo.
By summer it's rising more southerly.
Fukushima at 37 deg North is about latitude of San Francisco and central Missouri
so midday sun never gets directly overhead but always lights from south (left).
Shadows in left photo show it was taken shortly before noon.

 

[MadderDoc]

I am carrying as an open question whether that crane was always in just that spot.<..>

That's pretty exotic. It'd be the last thing I'd imagine moved anywhere since it fell from its rails under the roof in connection with the explosion on March 14th.

The dark circle in that Cryptome #47 shows in early helicopter videos pre- 24 March
but not in later photos or videos

It's called apophenia. If you look carefully in the March 16th source video, you can see the outline of the dark shape is actually the inner edge of steam plumes moving about it. Consequently the dark shape is 'alive', changes shape,and does only in a brief moment appear as a circle. The video has been taken a few hours pre-noon, i.e. the sun is behind the camera to the left, and the wind and the plume is going in the direction of the camera. Hence the space over the reactor where no steam is condensing appears relatively dark, while there is no condensate there to scatter light, and the area is being shaded by the outgoing plume.

The photo you have to the left is from March 24th, when the building for a brief period paused steaming. It may have been exhausted after producing the grand black smoke event on the night before.

 

[jim hardy]

The video has been taken a few hours pre-noon, i.e. the sun is behind the camera to the left, and the wind and the plume is going in the direction of the camera. Hence the space over the reactor where no steam is condensing appears relatively dark, while there is no condensate there to scatter light, and the area is being shaded by the outgoing plume.

makes sense. I did note it morphing in the video.

What a great word - apophenia. Could well be. That's why i asked.

thanks for the thoughtful reply ......

old jim

 

[MadderDoc]

<..>What a great word - apophenia. Could well be. That's why i asked.

Don't worry about it, it is not a disease, not even a particular frailty of the human mind., it's been on Earth for eons before humans even existed, so polar bears have it too :-). One could say the possibility of assigning meaning to patterns and have reality disappoint it, is a logical consequence of having, in the first place, the ability to assign meaning to patterns perceived by the senses.

 

[MadderDoc]

It is a scary thought that the public illusion that the steam plumes from unit 3 all came from the spent fuel pool might have been possible to bring about and uphold -- even if there had been no plume originating from anywhere near it.

However we were spared of that -- because one of Unit 3's two main plumes did in fact originate rather close to the spent fuel pool, at the area of the gate between the reactor area and the pool.

This particular spot is technically difficult to get a picture of, being hidden as it is underneath of a lot of scrap metal from the wrecked roof. Roof covering, rebar, and twisted and rustyburnt roof girders are layered above it. It appears to have been close to an epicenter of something effecting extreme heat, humidity and mechanical forces. I have inserted below to the thermographic overlay, a view to the pool gate area:
http://gyldengrisgaard.eu/fuku_docs/111008_05enhovl_main2vent_thumb.jpg


http://gyldengrisgaard.eu/fuku_docs/111008_05enhovl_main2vent.jpg , http://gyldengrisgaard.eu/fuku_docs/main2vent.jpg , and the Tepco source video from an attempt to air sample the location

 

[jim hardy]

it is not a disease, not even a particular frailty of the human mind.,

not to worry it wan't taken that way.
It's as natural as sitting under a shade tree with your kids imagining objects in the clouds.
It's probably the mechanism by which we read.

Doubtless the same photo puts similar images on our respective retinas, but mammal vision being a mediocre optical instrument with a fabulous computer assist, what winds up in our cerebrums will be markedly different.

That video showing the round plug under the crane rail is the first and only detailed picture I've seen of that region. It closes off some previously unterminated trains of thought for me.
I made a career as a troubleshooter by exploring blind alleys. Occasionally one of them has a jackpot at its end but usually they don't and it is better to not admit one was silly enough to consider going down those.
When you hit one that everybody else dismissed they think you're smart but really I'm just too dumb to give up.
(via that obtuseness ii did once find third harmonics burning up transformers , to astonishment of pooh-poohers.. )

....

to an epicenter of something effecting extreme heat, humidity and mechanical forces.

Steam can exist as superheated vapor so i can imagine 500+ degree exhaust stream up there when cooling water is low .

As i said earlier were i there i'd have tried to keep modest superheat on the temperature indicators . Subcooled means you have more water than is necessary, and too much water in the basements was an early problem. Slight superheat means you are not far from balance and i would have shot for ~50 dereesF. I would have forced subcooling just once to verify it's not critical(if it is it'll boil all the water you can throw at it).
That's just my thoughts, haven't heard it from anybody actually there.

if it's like a mine explosion everything will be pointing away from the epi-center.
I'm curious as to direction of the rebar that shows up in the unit 3 sfp video.
Did it fall in or is it the remnants of a wall?

......

I do ramble. But old men do that.

Thanks for your kind thoughtfulness. And the great work you are doing with video and cold hard logic.

old jim

 

[MadderDoc]

<..>
if it's like a mine explosion everything will be pointing away from the epi-center.
I'm curious as to direction of the rebar that shows up in the unit 3 sfp video.
Did it fall in or is it the remnants of a wall?
<..>

The problem as I see it is that one would need to hypothesise a series of events to explain the damage to the roof. It's always been the confusing thing about Unit 3 that you see so much diversity of destruction. Leaving aside what happened after the explosion...

and -- it may seem awkward, but I prefer to take my scenario of events in time reverse:

I'd say the _last_ phase of destruction would have involved the return of heavy debris elevated to great heights by the mushroom cloud. I believe a portion of that debris landed in the quadrant of the building where the SFP is located. My reason for believing this is the twofold, that a lot of debris from obviously roof covering is found in this quadrant while little elsewhere on the building top -- and, that the remnants of the south-most roof-girders appear to have been affected by a force from above, such as to make them warp and drop precipitously towards the service deck.

Before that phase I imagine the fall of the overhead crane and the remnant roof girder construction down to the service deck. (is there a mechanics man on board, what would be the timing of such a fall??) The remnant roof girder construction has hung on to a pillar and so hinged at its east end, while its west end slammed down towards the service deck. This may have introduced the warping already spoken of. Due to the orientation of the diagonal reinforcements in the two-beam girder construction
|\|\|\|\|\|\|/|/|/|/|/|/| , if you get the idea,
the midpoint of the girder would seem to me the weakest spot for a warp, and indeed the observed warps are centred about the midpoint of the girder.
The huge crane beams across the building may have fallen in two stages, initially hinging around one end. However those beams ended up falling down in both ends (need a mechanics man again, what would be the timing of such falls, say from 7 m above floor for the beams and 15 m for the roof girders-)

Before that phase we would have the mushroom cloud racing upwards, with at that stage perhaps little else than the roof covering left in its way to destroy? Or perhaps, with the explosive evolution of steam, it overlapped with and added explosive power to the destruction of the walls.

Before that phase, we would have explosive expulsions of walls above the service deck, to the south, west, and to the north. The north and south walls took away with it the north and south ends of the roof girder construction, The west wall took away with it the support for the overhead crane. And there would have been explosions involving also the floors below the service deck.

And, initially .. we could have a massive hydrogen flare shooting out though the roof and the wall, upwards in an E or ESE direction, igniting and flashing back into the building. Or something that can similarly produce those damages to the roof girders which we find in that section of the roof. I can't imagine any explosive or mechanical effect alone to produce the gross drooping deformation and degrading of those girders hanging over the edge of the pool. Here look below, I think you can see what I mean, for this damage I feel you need to hypothesise heat, real heat, not just the heat of a brief hydrogen explosion:

original photo

 

[jim hardy]

what would be the timing of such falls, say from 7 m above floor for the beams and 15 m for the roof girders-)

first approximation, from high school physics

d = 1/2 at^2 and a = 9.8 m/s^2

d = 4.9 t^2
t= √(d/4.9)

√(7/4.9) = 1.2 sec (1.195 to too many places)

√(15/4.9) = 1.7 sec (1.749 " )

If they were set free at instant of explosion.
I'd guess west end probably was.

Were any roof girders thrown to North and South? Seems there was a girder with light fixture on North side.

heat sure seems a possibility after it quit steaming.

will take a look at that picture after figure out how to save it hi-res.

old jim

 

[jim hardy]

Here look below, I think you can see what I mean, for this damage I feel you need to hypothesise heat, real heat, not just the heat of a brief hydrogen explosion:

I guess they could have got buckled upward by initial explosion if the roof fasteners can transmit tension. Sure need a civil type.

But i see what you mean about the heat. Were ones on other side that aren't so discolored, bent similarly?

I am trying to decide whether to attach significance to the columns .
All the columns on west side were toppled outside and hanging by their rebar , early photos show that well.
These on east side were bent and almost toppled inside, fractured at deck level,
as if a slug of something inside with considerable momentum pushed building that way(west) and pulled east columns inward by tension through roof beams.
Explosive force should have pushed them all outside.

Not asserting that happened - it just looks like the entrance to one of my "blind alleys". Will think on it a day or two. Maybe something will pop up that closes it.

old jim

 

[MadderDoc]

first approximation, from high school physics

d = 1/2 at^2 and a = 9.8 m/s^2

d = 4.9 t^2
t= √(d/4.9)

√(7/4.9) = 1.2 sec (1.195 to too many places)

√(15/4.9) = 1.7 sec (1.749 " )

If they were set free at instant of explosion.
I'd guess west end probably was.

I am sure this is a stupid question: so it doesn't matter whether it hinges at one end or not?

Were any roof girders thrown to North and South?

The northernmost girder was twisted axially 180 deg and bent 90 degrees so appears to have been dragged down along the north face of the building. I imagine remaining fixture to the wall dragged it overboard and down, But at least it is still there and to have suffered nothing but mechanical damage, although in a gross manner. The southernmost girder appears as good as MIA. I believe we _may_ be seeing its end concrete anchor block pointing up in the photo crop, east of the pool and close to the level of the deck. (see encircled below) If so, it only further emphasises the question, how on Earth did it degrade so utterly. I have no idea where the rest of it is.

 

[MadderDoc]

I guess they could have got buckled upward by initial explosion if the roof fasteners can transmit tension. Sure need a civil type.

I assume you mean the fasteners for the corrugated iron. They are well visible
http://www.gyldengrisgaard.eu/fuku_docs/japan-nuclear-2012-2-20-7-20-1.jpg .

 

[r-j]

Did anyone ever figure out what was causing the smoke?

http://www.csmonitor.com/USA/2011/0...What-s-in-the-smoke-emerging-from-Fukushima-I

http://www.rt.com/news/fukushima-smoke-reactor-radiation/

 

[jim hardy]

I am sure this is a stupid question: so it doesn't matter whether it hinges at one end or not?

not at all.
It changes things because instead of simply falling the beam rotates about the hinged end.
Which brings its moment of inertia into play. And where the trolley was parked.

It'll fall slower and hopefully some student who's taking dynamics will offer to help...

..


looking at those roof supports, whatever was attached to them must be pretty flimsy for it didn't fail any of them. I don't see them as buckling any beams. Thanks for pointing them out.

Those photos are amazing - i sure missed some photo releases. Got some catching up to do. Any pointers ? Maybe a new Cryptome file?

 

[MadderDoc]

Did anyone ever figure out what was causing the smoke?

http://www.csmonitor.com/USA/2011/0...What-s-in-the-smoke-emerging-from-Fukushima-I

http://www.rt.com/news/fukushima-smoke-reactor-radiation/

There is so little to go on, r-j. :-(
We have webcam images but no photos from the ground
(unlike as we have it for the black smoke event of March21st.)
We have the doserate at the main gate of the plant
(located to the west inland side of Unit 3, to the left side of the webcam images).
We have from officialdom at the time, the assurance that doserate did not change in connection with the black smoke event,
and some speculation of causes none of which involved the reactor. Wherein perhaps lies the answer.
http://www.gyldengrisgaard.eu/fuku_docs/March23th_2011_thumb.jpg
http://www.gyldengrisgaard.eu/fuku_docs/March23th_2011.jpg

 

[Borek]

To All, please remember to stay on topic.

 

[zapperzero]

All the columns on west side were toppled outside and hanging by their rebar , early photos show that well.
These on east side were bent and almost toppled inside, fractured at deck level,
as if a slug of something inside with considerable momentum pushed building that way(west) and pulled east columns inward by tension through roof beams.
Explosive force should have pushed them all outside.
old jim

For what it's worth, the blast would probably have started at deck level, east side.

So, columns get fractured at that level, walls fly away but the columns don't have time to fall, because moments later the blast (augmented now as parts of it got reflected off the walls and ceiling) WHACKS into the west side of the building, pushing the whole construction (which is still connected with roof girders) over that way. I also seem to remember the bridge collapsed at that end... but that might be my awful memory playing tricks again.

Does this make any sense?

 

[Rive]

These on east side were bent and almost toppled inside, fractured at deck level,
as if a slug of something inside with considerable momentum pushed building that way(west) and pulled east columns inward by tension through roof beams.
Explosive force should have pushed them all outside.

Below the deck level the building is not symmetrical: there is more 'volume' on the west side.

So if you cut the explosion in half: there were an explosion on the top level, this just 'blow up' the upper part like a balloon and let fly the wall panels and roof, but did not break the connections between the roof beams and the columns, even if some columns were broken.

The explosion below the deck were asymmetrical and broke the columns only on the west, so they have collapsed and - through the roof beams - pulled the columns on the other end (east) inward.

 

[MadderDoc]

<..> did not break the connections between the roof beams and the columns, even if some columns were broken. <..>
.

Post explosion, the only remaining attachment between roof beams and columns is at the middle column to the east. This column is broken and leans inward allowing the angling downwards of its attached roof beam.

Columns to the north of it are in relatively fine condition and still standing. Columns to the south of it are broken and have lost their tops, including the mounting socket for the roof beams.

The two northernmost roof beams have been retracted from their sockets in the top of the intact columns, with no apparent bending of the 8 steel guide rods of the sockets, and with only little damage done to the concrete around them. The retraction of roof beams from these sockets would therefore need to have been done while the roof construction was in a near horizontal position, and by employing a ccw rotation (as seen from above) of the entire roof construction, with the center of rotation close to the east middle column.

There is little to suggest the south roof beams were in a state at that moment, such as to be able to resist the ccw motion or to do damage to their columns by it, i.e. beams were likely not fixed in touch to their columns -- e.g. the roof had been lifted above their level, or the tops of the south columns were gone, or the roof beams had been structurally degraded.
http://www.gyldengrisgaard.eu/fuku_docs/Unit3_top_NE_thumb.jpg
http://www.gyldengrisgaard.eu/fuku_docs/Unit3_top_NE.jpg

 

[westfield]

<snip>

The two northernmost roof beams have been retracted from their sockets in the top of the intact columns, with no apparent bending of the 8 steel guide rods of the sockets, and with only little damage done to the concrete around them. The retraction of roof beams from these sockets would therefore need to have been done while the roof construction was in a near horizontal position, and by employing a ccw rotation (as seen from above) of the entire roof construction, with the center of rotation close to the east middle column.

<snip>

Maybe I've misunderstood, I can't see any evidence or need of a ccw rotation of the general roof structure in the horizontal plane. An overhead image doesn't show rotation in relation to those three trusses, they have just moved west. Two separated from the wall (and caused considerable damage to the concrete around their "mounting slot") and one stayed attached, breaking the wall structure further down instead.

It appears to me the whole roof structure (in general) has moved west as Rive suggested. It would be unsurprising if the failure of the west wall structure, even without it's apparent westerly direction of movement was enough to cause the roof trusses to pull away from their east wall attachments or alternatively break a section of the east wall structure as we see those three trusses now. The attachment "studs" would not be damaged as the truss mounting block is clear of those before it falls out of the "slot".

 

[Rive]

Regarding the explosion on U3 top level the actual status of U4 roof might be useful as it shows signs of various, but more or less systematic damages but without the side columns broken under the deck level.

I still think that the main difference was the breaking of west side columns under deck level (what was the result of the difference between the strength of the explosions).

 

[MadderDoc]

<..> I can't see any evidence [..] of a ccw rotation of the general roof structure in the horizontal plane.<..>

 

[westfield]

The image shows the roof structure is wholly bent half way across. However if you look at the eastern end of the three trusses we have been referring to there is no rotation.

 

[westfield]

Regarding the explosion on U3 top level the actual status of U4 roof might be useful as it shows signs of various, but more or less systematic damages but without the side columns broken under the deck level.

I still think that the main difference was the breaking of west side columns under deck level (what was the result of the difference between the strength of the explosions).

Thinking the same way. The U3 roof structure collapse and damage to east wall framing may not be caused directly by the explosion at all but indirectly by the structural failure in the NW corner of the RB in turn pulling the roof and east wall down. As you say, Unit 4 is great evidence of how once the wall panels and roof cladding are blown away the remaining structure still remains incredibly strong. To add to that, the "slice" of roof cladding in the north end of U4's roof may hint at how the cross braces in the same area of U3 were severed.

 

[MadderDoc]

The image shows the roof structure is wholly bent half way across. However if you look at the eastern end of the three trusses we have been referring to there is no rotation.

I wonder how you come to that conclusion. On the eastern stretches, the projection of the three trusses to the floor appear to me to be either parallel to the crane beams or rotated somewhat ccw relative to them. However the crane beams are rotated ccw relative to the building, so something parallel to them would seem to have been too.

 

[MadderDoc]

<..>
I am trying to decide whether to attach significance to the columns .
All the columns on west side were toppled outside and hanging by their rebar , early photos show that well.

Indeed, they have been arranged such that the most natural thought is they fell rather much in unison.

These on east side were bent and almost toppled inside, fractured at deck level,
as if a slug of something inside with considerable momentum pushed building that way(west) and pulled east columns inward by tension through roof beams.
Explosive force should have pushed them all outside.

Yes, but in the macro scale that may also have happened. If you look in drone photos from the south side, the whole eastern wall of unit 3 does appear to curve outward. Then of course there are details like the top pillars, as you mention 4 of which have become fractured, and are leaning.

One of those, the middle one is forced down by the roof truss to which it is still attached, so no wonder it is leaning inwards. The next leaning pillar towards the south, we find devoid of its top, apparently resting against the sunken remains of the roof truss it was originally attached to, under the influence of gravity of concrete fragments dangling from its top, and perhaps also because most concrete matrix was lost from the inwards side of the fracture.

I am not saying this arrangement couldn't have involved a series of events with at one stage an inward tension from the roof beam, however I fail to see why it should be a necessary assumption to make. We are in that exact area where we saw the initial huge flare or fireball shooting out the building, to the east and upwards far above the roof. So wouldn't it be simpler to assume this really caused a whole lot of destruction in this upper corner of the building, to the end of the roof beams as well as to the top section of the pillars where they were attached, i.e. to where they were fixed to each other. And after that, well, gravity is always ready to make the final arrangement out of the pieces.

(Similarly just for completion, with the next pillar towards the south, which is almost vertical and has its roof beam MIA, why should we try to explain that its roof beam first pulled inwards the pillar, after which the roof beam disappeared, when we know about that huge fireball? And then finally there is the south-most pillar which has a big chunk of concrete hanging from its top, making it lean north around its fracture at the level of the crane beams, that one never had a roof beam attached to it.)

 

[MadderDoc]

looking at those roof supports, whatever was attached to them must be pretty flimsy for it didn't fail any of them. I don't see them as buckling any beams. Thanks for pointing them out.

I was surprised that there were so little in the way of attachment. The ~7 m corrugated iron roof coverings appear to have been just clipped on at the ends. and then tied in with some rebar and concrete poured on top of it. But then of course it was never built to resist a volcanic eruption from below :-)

Those photos are amazing - i sure missed some photo releases. Got some catching up to do. Any pointers ? Maybe a new Cryptome file?

I think I got them from cryptome .. yes here:.
http://cryptome.org/2012-info/daiichi-022012/daiichi-022012.zip
but as you can see they are from February 2012, when the press with cameramen were invited in. I hope, and I'd expect a repeat photo safari at time soon, for a balanced winding down of PR -- not to often but also not too far apart -- 3 months would seem a good technical choice at this stage. Perhaps not much more to be hoped coming from Tepco, now more than one year on, but the existing photo and video collection built over the last year is still a great resource, and the content could still be improved by replacing with versions of higher fidelity to the original material.

 

[MadderDoc]

I guess they could have got buckled upward by initial explosion if the roof fasteners can transmit tension. Sure need a civil type.
But i see what you mean about the heat. Were ones on other side that aren't so discolored, bent similarly?

I find it curious that the hypothesis of possible heat damage to structures in the upper SE corner of Unit 3 is commonly met with disbelief. To me it would seem to be rather the default position that such heat damaged structures should exist in the wrecked building. Indeed were nothing immediately obvious it would make sense to me to look more carefully for evidence of it. Weird then, to experience an urge rather to explain away, or be blind to it.

http://www.gyldengrisgaard.eu/fuku_docs/20120311193727exp2_thumb.jpg

http://www.gyldengrisgaard.eu/fuku_docs/20120311193727exp2.jpg

 

[elektrownik]

http://enenews.com/japan-nuclear-experts-fears-corium-not-totally-covered-in-water-at-reactor-no-1-may-only-be-15-inches-deep-even-lower-than-no-2

 

[Yamanote]

http://enenews.com/japan-nuclear-experts-fears-corium-not-totally-covered-in-water-at-reactor-no-1-may-only-be-15-inches-deep-even-lower-than-no-2

I expect a similar situation in all three reactors.

If there is a vessel with (given) holes at the bottom, one can only maintain the waterlevel inside by pouring more water into the vessel than escapes through the holes. Obviously this is not possible at Fukuichi, otherwise they would have flooded the PCVs already. Call it reactor design flaw or not, unless the leaks in the PCVs can be sealed, this situation will not change. And we know that the techniques for that are still under development. There is no quick "plan B", so time has to show us...

 

[MadderDoc]

Thinking the same way. The U3 roof structure collapse and damage to east wall framing may not be caused directly by the explosion at all but indirectly by the structural failure in the NW corner of the RB in turn pulling the roof and east wall down.

One can say a priori, that an explosion within the confines of the building cannot cause the collapse of its roof structure directly. It can cause it only indirectly by removing its supports, or by damaging parts of it such as to make it loose integrity. in any case: to bring the roof structure down, there is only gravity. So no quibble there.

Your suggestion otoh that specifically the damage to the wall framing in the south section of the east wall might have been caused by a gravity pull mediated by the collapsing roof structure appears to be entirely speculative. You make no reference to any supporting evidence for that theory, nor evidence to contradict other possible causes of the damage. And in fact it flies in the face of the evidence.

Here, from a video of the explosion, in the very first frame which indicates something untoward is going on with the building, we see explosive damage being done to the walls in the southern part of the east wall:

In the next frame a huge flame burns out through the southern part of the east wall.

It continues to burn for the next many frames, here still visible after more than half a second into the event:

So why should we think none of that damaged the east wall and the roof beams in this part of the building?

 

[zapperzero]

I find it curious that the hypothesis of possible heat damage to structures in the upper SE corner of Unit 3 is commonly met with disbelief. To me it would seem to be rather the default position that such heat damaged structures should exist in the wrecked building. Indeed were nothing immediately obvious it would make sense to me to look more carefully for evidence of it. Weird then, to experience an urge rather to explain away, or be blind to it.

I can see that the hydrogen explosion made a lot of heat, relatively. I do not see how that brief, intense fireball might have had time to heat up the insides of those rather sizeable steel beams.

I'd expect to see no more than light scouring from heating . Blast effects and the structure tearing itself apart afterwards would seem to me to account in a satisfactory manner for most of the damage.

This is not to say that I don't see how that area might have been very hot for a long period of time (days maybe? as dry steam was being emitted?), leading perhaps to further warping.

 

[MadderDoc]

I can see that the hydrogen explosion made a lot of heat, relatively.

Yes. The hydrogen explosionists appear to claim for their theories the combustion of in the order of magnitude 1000 kg hydrogen. My BOE says that's about 150000 MJ heat of combustion.

I do not see how that brief, intense fireball might have had time to heat up the insides of those rather sizeable steel beams.

I am not sure which brief intense fireball you are referring to. I am talking about the fire phenomenon visible above the south east corner of the building for the better part of one second after the building blew up (or should we say 'started to blow up'? :-) Many burnt fingers have been caused by not realising how little heat it takes to heat iron. We are in the neighbourhood of a few hundred MJ/ton/1000K says my BOE.

So, if the hydrogen explosionists could be so kind as to spare some kg of hydrogen for a http://www.gyldengrisgaard.eu/fuku_docs/20120311193727exp2.jpg , which however was undoubtedly present, and with possibly some effective metal heating hydrogen combustion directed to the part of the building in question.

I'd expect to see no more than light scouring from heating . Blast effects and the structure tearing itself apart afterwards would seem to me to account in a satisfactory manner for most of the damage.

Perhaps. You are not being very specific.

This is not to say that I don't see how that area might have been very hot for a long period of time (days maybe? as dry steam was being emitted?), leading perhaps to further warping.

I'd consider that to be just speculative. I don't think it well fits the evidence.

 

[zapperzero]

I am not sure which brief intense fireball you are referring to. I am talking about the fire phenomenon visible above the south east corner of the building for the better part of one second after the building blew up (or should we say 'started to blow up'?

In the beginning there is an actual round fireball poking out of that corner.

So, if the hydrogen explosionists could be so kind as to spare some kg of hydrogen for a perhaps insignificant fire phenomenon[/url], which however was undoubtedly present, and with possibly some effective metal heating hydrogen combustion directed to the part of the building in question.

Undoubtedly there was some heating. I am "just" saying that the most energy, by far, went into making a pressure wave. Incidentally, its leading edge was very hot also. But the inside of that impressive ball of fire is empty, at very low pressure and relatively cool, the flame front passes over any given thing for only the briefest of moments, because it is supersonic. If you look at the photos more, you will see that there is still some paint, in patches, on even the most corroded, darkened beams. That does not jive with scorching heat.

I'd consider that to be just speculative. I don't think it well fits the evidence.

Me neither. It's just a remote possibility.

 

[MadderDoc]

In the beginning there is an actual round fireball poking out of that corner.

When, in the beginning? Perhaps you can use this as a reference.

Undoubtedly there was some heating. I am "just" saying that the most energy, by far, went into making a pressure wave. Incidentally, its leading edge was very hot also. But the inside of that impressive ball of fire is empty, at very low pressure and relatively cool, the flame front passes over any given thing for only the briefest of moments, because it is supersonic. If you look at the photos more, you will see that there is still some paint, in patches, on even the most corroded, darkened beams. That does not jive with scorching heat.

The visible fire phenomenon is almost entirely outside the building, so only relevant from what it tells us about what's concurrently happening inside the building, e.g. where does the burning substance originate from, what source feeds it, what route did it take from there to erupt on the outside of the building, what were the conditions for damage along that route while it burned.

 

[MadderDoc]

<..>. If you look at the photos more, you will see that there is still some paint, in patches, on even the most corroded, darkened beams. That does not jive with scorching heat.

Apparently 'hydrogen explosion' can be used to explain any effect, any degree of damage, and is not supposed to be held to any high evidential standard. Otoh, if there is just a few patches of something looking like paint to be found on a piece of scrap metal, it is concluded that it cannot have been damaged by heat. I wonder if you'd seriously be willing to use that criterium, if you were shown corroded beams with not a speck of paint left, or 'hydrogen explosion' and a bit of handwaving would be used to explain that away too.

 

[jim hardy]

i'm way behind you fellows.

I can't rule out the beams having got roasted by hot gas during or afterward. Rust suggests the paint got cooked off.

Still musing on the columns.
The crane rail, so obvious in that photo, ties the columns together for N-S forces. The east ones still standing fairly well retained that alignment.
The west ones did too, from aerial March 20 (2011) shots of them dangling by rebar.
The resolution of those isn't good enough to say whether the rail is still attached to them but it doesn't appear to be laying under the crane ends up on the deck.

If that substantial beam is one continuous rail it'd add some rigidity for E-W forces too, making the columns into a wall-like structure. That could explain why the [STRIKE]east[/STRIKE]west (edit) columns toppled together as a unit. I'd say the [STRIKE]west[/STRIKE]east ones almost did too.

plodding along. if you guys dismiss this as beating the obvious I'm not offended.

visiting kids now and away from my computer else i'd post that 20 march photo..

old jim

 

[MadderDoc]

Still musing on the columns.
The crane rail, so obvious in that photo, ties the columns together for N-S forces. The east ones still standing fairly well retained that alignment.
The west ones did too, from aerial March 20 (2011) shots of them dangling by rebar.
The resolution of those isn't good enough to say whether the rail is still attached to them but it doesn't appear to be laying under the crane ends up on the deck.

If that substantial beam is one continuous rail it'd add some rigidity for E-W forces too, making the columns into a wall-like structure.

It is not a continuous rail, it is in 6 sections corresponding to the wall structure. The sections appear to have been laid out on slip pads on top of the pillar supports. This would seem to be in order to guard against heat expansion's cracking up the building over time, so the rail sections are unlikely to be firmly attached to the pillars. The rails sections from the west wall seem to have just slid off the wall pillars once they landed top down.