Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Cire]

2) The initial fireball (Boom) isn't a fireball -- it is a pure, white puff of steam or smoke that only ignites after entering the outside air. After that, it doesn't expand or blow outward, it just seems to burn up and consumes itself. The building explodes next. The vertical plume of dense smoke is the final visible event. I haven't matched each of these to the boom, boom, boom sounds, though.

This is what occurs when you initially consume free oxygen in a fuel rich environment. As the fuel is pushed outward and mixes with free air combustion resumes.

You can see the effect here. This video is a test coal mine explosion.

http://www.cdc.gov/niosh/mining/products/movies/fireball.avi

 

[flyingblind]

NRC suspects RPV 2 has been breached.

http://www.nytimes.com/2011/04/07/world/asia/07japan.html?_r=1

If true, can anything be done to arrest the process?

1st post so hello.
Quote from the site "This is the (bitmap) PDF file of the NRC assessment obtained supposedly from a source outside the government. This material was cited by a New York Times report (U.S. Sees Array of New Threats at Japan’s Nuclear Plant,"
http://fukushimafaq.wikispaces.com/Miscellaneous"

 

[razzz]

REGARDING COMPRESSION ARTIFACT AND RESOLUTION

Just for grins, here are the actual pixels I am able to resolve, not from the video, but from the links to the frame grabs I posted. ROI is the initial white puff and red fire ball./QUOTE]

shogun338, TCups, AntonL, Cire: Frame by frame I see same as a white object comes up first then the flame; object ejected? roof peeling up? gas breaking free? I don't know. Before that as I watch, at extreme magnification, the roof line (which is the top of the parapet wall) and the building esp. the roof itself, seems to rise and fall 2 or 3 times maybe more like it's alive with explosions inside or at least pressures. Then it appears like part of the parapet wall topples inward before the fireball shows.

Soundtrack would probably coincide with those early roof movements. The description of a RPV clanging against the Primary shell, makes sense if there is enough movement.

Later on in that same fireball area, the smoke turns greenish with movement, I'm think'in the FHM is passing through sideways and all the debris in the updraft is mostly leftover roof disintegrating on the way up and way down. Thought I saw in the 'flyover' video, large pieces of green laying all over near that area. If it was cast iron, it would shatter.

What mechanical force would be affecting the whole event?

[multiple edits, since I'm a product of public edumakation]

 

[shogun338]

Japanese authorities are planning to use a Honeywell T-Hawk micro air vehicle to check radiation levels at the crippled Fukushima Daiichi nuclear plant, while unmanned drone helicopters from France are also joining the effort.

Read more: http://news.cnet.com/8301-17938_105-20051499-1.html#ixzz1IooaDiN5

 

[Jorge Stolfi]

Well, consider this scenario for any or all of reactors #1--#4: after water circulation in the spent-fuel pool stopped, the water boiled off until a substantial part of the fuel was exposed. The exposed part got hotter and hotter. At some point above 300C the zirconium started reacting with the rising steam and generated H2.
The H2 left the SFP (no mostly oxygen-free) and diffused though the building, where it mixed with O2. When the exposed fuel reached 700C the neutron absorber baffles melted or disintegrated. Criticality or near-criticality ensued. The sudden heat pulse and the residual water created a steam explosion in the SFP (white blast that pierced the roof in video of #3). The red-hot fuel bits thrown up by the steam explosion ignited the H2+O2 outside the SFP, that exploded throughout the building.

IF there were indeed three blast sounds from #3, then blast 1 would be the steam explosion due to the criticality event; bast 2 could be the H2 explosion in the upper floor; and blast 3 could be an H2 explosion below the main deck.

 

[AntonL]

REGARDING COMPRESSION ARTIFACT AND RESOLUTION

Just for grins, here are the actual pixels I am able to resolve, not from the video, but from the links to the frame grabs I posted. ROI is the initial white puff and red fire ball.

http://i306.photobucket.com/albums/nn270/tcups/Fukushima%20Foto%20Files/Picture2-1.png

http://i306.photobucket.com/albums/nn270/tcups/Fukushima%20Foto%20Files/Picture3-1.png

http://i306.photobucket.com/albums/nn270/tcups/Fukushima%20Foto%20Files/Picture4-1.png

Not great, but more than 8 pixels for sure. Plus the tower just to the left will give an idea of edge artifact and contrast resolution.

@TCups below the full image, you are already working with an enlarged image
Judging from the explosion unit 1 picture , the cctv camera is a 4:3 image sensor ie PAL=625 lines or NTSC=525lines, so any pixels we count are already from a very poor recording medium. I think this corresponds to your picture 3
[PLAIN]http://k.min.us/imBHTI.JPG
[PLAIN]http://k.min.us/imBb6c.JPG

 

[Emreth]

There is slightly more to that BBC image, their video is clipped a bit from the original.

 

[shogun338]

REGARDING COMPRESSION ARTIFACT AND RESOLUTION

Just for grins, here are the actual pixels I am able to resolve, not from the video, but from the links to the frame grabs I posted. ROI is the initial white puff and red fire ball./QUOTE]

shogun338, TCups, AntonL, Cire: Frame by frame I see same as a white object comes up first then the flame; object ejected? roof peeling up? gas breaking free? I don't know. Before that as I watch, at extreme magnification, the roof line (which is the top of the parapet wall) and the building esp. the roof itself, seems to rise and fall 2 or 3 times maybe more like it's alive with explosions inside or at least pressures. Then it appears like part of the parapet wall topples inward before the fireball shows.

Soundtrack would probably coincide with those early roof movements. The description of a RPV clanging against the Primary shell, makes sense if there is enough movement.

Later on in that same fireball area, the smoke turns greenish with movement, I'm think'in the FHM is passing through sideways and all the debris in the updraft is mostly leftover roof disintegrating on the way up and way down. Thought I saw in the 'flyover' video, large pieces of green laying all over near that area. If it was cast iron, it would shatter.

What mechanical force would be affecting the whole event?

[multiple edits, since I'm a product of public edumakation]

I think the FHM is still in Unit 3 over reactor . In some of the over flight videos you can see green near this center portion and it looks like it is helping support this section . In Unit 1 on left side there is a large debris pile that looks like it is supported in the same way by the FHM . In Unit 4 it is on left side also and can be seen easily . I don't think the FHM would be built out of cast iron because it would be to brittle .

 

[AntonL]

IF there were indeed three blast sounds from #3, then blast 1 would be the steam explosion due to the criticality event; bast 2 could be the H2 explosion in the upper floor; and blast 3 could be an H2 explosion below the main deck.

Three blasts are TV-producers contribution

 

[|Fred]

I think the FHM is still in Unit 3 over reactor . In some of the over flight videos you can see green near this center portion and it looks like it is helping support this section . In Unit 1 on left side there is a large debris pile that looks like it is supported in the same way by the FHM . In Unit 4 it is on left side also and can be seen easily . I don't think the FHM would be built out of cast iron because it would be to brittle .

there are clear pictures from video and photo showing that the top crane is the structure laying above the reactor concrete shield location. The smaller crane and the FHM is elsewhere , considering color coding and picture interpretation I think it is safe to conclude that the FHM is on the north of the unit to the west side of the pool , one floor bellow operating floor

 

[shogun338]

Referring to the possibility of installing the seawater pumps inside buildings, the former TEPCO engineer said, "It would have been a major project because various pipes are laid out under the pumps, and so all of that would also have had to be moved."

A midlevel TEPCO official also said money was a big reason why repairs and changes to the No. 1 plant were not made. http://www.asahi.com/english/TKY201104060126.html

 

[razzz]

I think Unit 3 after blast, some kind of rods around crane (green).

 

[Emreth]

I triangulated the camera location for the explosions to be around 3-4 miles SW (~53 degrees) of building 4 (or ~58 degrees of building 5). I calculated the building angles with respect to the camera using the relative widths of the projections of the south and west walls on the image compared to their actual proportions (about 3/4) and used the distance between the buildings (~3500 ft). The camera is 15000-17000 ft south and 11000-13000 ft west of building 4. I can't spot any of the features shown in the explosion videos on google Earth around that location, maybe someone can figure it out or refine/check the calculations? There might be errors but the camera is definitely not 20 km away as some suggested.

Edit: Sorry it was a bit late and my brain was mushy, changed building 7 to 5.

 

[shogun338]

there are clear pictures from video and photo showing that the top crane is the structure laying above the reactor concrete shield location. The smaller crane and the FHM is elsewhere , considering color coding and picture interpretation I think it is safe to conclude that the FHM is on the north of the unit to the west side of the pool , one floor bellow operating floor

If standing on top of turbine building looking at Unit 3 what is the location of the FHM in Unit 3 . The top two sections on Unit 3 and Unit 4 are the same and the lower section of blowout in section two is the reactor room floor . Are you saying the FHM is below this ?

 

[|Fred]

Referring to the possibility of installing the seawater pumps inside buildings, the former TEPCO engineer said, "It would have been a major project because various pipes are laid out under the pumps, and so all of that would also have had to be moved."
A midlevel TEPCO official also said money was a big reason why repairs and changes to the No. 1 plant were not made. http://www.asahi.com/english/TKY201104060126.html

Basically they are just saying that they build the Reactor from GE and did not made huge if any design modifications they likely just added some general seismic and Tsunami protection, rather that redesigning the unit to be able to sustain stuff from design.
Such redesigning would have require money that's a given but it also assume know how and I doubt they had it at the time.

 

[|Fred]

If standing on top of turbine building looking at Unit 3 what is the location of the FHM in Unit 3 . The top two sections on Unit 3 and Unit 4 are the same and the lower section of blowout in section two is the reactor room floor . Are you saying the FHM is below this ?

[PLAIN]http://i.min.us/im7mIU.jpg

 

[artax]

I triangulated the camera location for the explosions to be around 3-4 miles SW (~53 degrees) of building 4 (or ~58 degrees of building 7). I calculated the building angles with respect to the camera using the relative widths of the projections of the south and west walls on the image compared to their actual proportions (about 3/4) and used the distance between the buildings (~3500 ft). The camera is 15000-17000 ft south and 11000-13000 ft west of building 4. I can't spot any of the features shown in the explosion videos on google Earth around that location, maybe someone can figure it out or refine/check the calculations?

good work, though the land begins to rise around 6 miles away, so I think there might be a camera location on route 35 or route 36, maybe near the golf course, on the large white rectangular building or at the substation.

There's very few roads that go up to the peaks, but mybe they carried cameras up to higher ground.
Do we know who shot the videos.
A more accurate bearing (in degrees roughly SW) from building/ tower relative positions in the video would help, and an altitude?!1

sorry didn't see your 58 degrees! will have a nother look.

There's a little track that snakes up to 300metres, left of the blue/grey quarry, looks like the best spot to me. SW of the road on stilts

loaction, 37 22 06 26 N, 140 56 17 61 E

Just noticed, from the relationship of tops of exhaust towers to the horizon, the altitude of video location is above tower height and I'm guessing the towers are 150m, so we're about right at 300m altitude.

 

[AntonL]

I triangulated the camera location for the explosions to be around 3-4 miles SW (~53 degrees) of building 4 (or ~58 degrees of building 7). I calculated the building angles with respect to the camera using the relative widths of the projections of the south and west walls on the image compared to their actual proportions (about 3/4) and used the distance between the buildings (~3500 ft). The camera is 15000-17000 ft south and 11000-13000 ft west of building 4. I can't spot any of the features shown in the explosion videos on google Earth around that location, maybe someone can figure it out or refine/check the calculations?

Which is building 7?

 

[artax]

there are a lot of the main roof girders on the left (S) side of unit 3 are nowhere to be seen, suggesting source over SPF. is that the conclusion you've come to? source over SPF, with almost certainty?

 

[|Fred]

I don't really get you are you saying they are or aren't roof structure south of u 3? I seen some, I also see deformation of the metallic roof structure on the north suggesting the infamous FHM did its do

 

[artax]

Fascinating!
1) those three bangs are definitely not echoes, and
2) the sound track contains more information than the video.
Thank you for the post, very much.

I think we should accept we don't yet have a sound track, these bangs are added afterwards. DEFINATELY!
I heard two of the IRA bombs when I lived in London at a distance of 3 and 7 miles, the sound gets dulled with distance ( a bit like the video images) and those sounds are artificial.

 

[Jakeh]

I think we should accept we don't yet have a sound track, these bangs are added afterwards. DEFINATELY!
I heard two of the IRA bombs when I lived in London at a distance of 3 and 7 miles, the sound gets dulled with distance ( a bit like the video images) and those sounds are artificial.

If that's the case (and it may be), it is not a bit surprising that (a) the sound effects person added in all the rumbling noises as well as the dramatic bangs and (b) counterintuitively chose to add 3 bangs rather 1 or perhaps 2.

The sound may have been traveling a much more direct route to the mike than you experienced in those London bombs. Unless you were on top of Hampstead Heath or Crystal Palace (or the like) at the time, there would have been a lot more reflection/muffling etc from buildings between the explosions and your ears.

Someone earlier cited the timing as proof the sound was artificial. That isn't exactly proof - if the timing is off, the soundtrack may just have been shifted in time against the video so the sound was a closer match to the picture for TV purposes.

 

[NUCENG]

PS. Also about item (1): one objection to them being fuel rods is that in the assembly they are held together by several horizontal "spacer" plates, which are missing in the pic.The outer square jacket is made of zircalloy, correct? If so it would have protected the rods from corrosion (very little steam inside it, not renewed) until the sleeve itself got busted.

The outer square jacket is made of zircalloy, correct? If so it would have protected the rods from corrosion (very little steam inside it, not renewed) until the sleeve itself got busted.
Yes, the channel or jacket is made of zircalloy. but the rods are being heated by the fuel inside the the channel and inside the zircalloy cladding. Heat is transferred from hot to cold materials through conduction, convection, or radiatiom. Conduction from the fuel centerline, to the edge of the fuel. If fuel has swollen to contact the cladding conduction through the cladding to its surface. Normally conduction/convection to water flowing past the rod. When the rod surface experiences dryout the conduction to steam is very limited and the transfer of heat becomes radiation. From the edge of the bundle heat may be tramsferred to the channel by the same three processes changing in the same order. By the time channels start Zirconium water reactions the fuel and clad are fully involved. The hottest point in the process descrived is the fuel centerline - thus PCT limits are the critical Safety Limit for operating nuclear reactors.

Once the zirconium water reaction starts on the clad, it is strongly exothermic heating clad further and accelerating the reaction rate. Some of the hydrogen being released reacts with the zirconium in rods to form hydrides which further increase rod embrittlement. All this heat inside a rod causes fuel swelling and gas pressures inside rods that can burst the cladding.

Cladding bursts could be big enough to spill fuel pellets of partially melted corium further blocking flow area for water and steam removing any remaining cooling flow. Eventually this process reaches and includes the channel.

However, AFAIK the spacer plates are made od steel (MP < 1500C) and the tubes of zircalloy (MP ~1800C). We know that some of the fuel in the SFP #4 was heated to at least 1000C (only way to make enough hydrogen for the explosion in #4). If heating continued past that point, eventually the steel plates would melt leaving the tubes loose. Is that correct?

Yes, Possible. However from the discussion above, the cladding on fuel rods is involved in Ziconium Water reactions which corrode the cladding, also allowing it to be eroded by high velocity steam. This process starts at the top of bundles as the water level drops. It also proceeds from the core centerline outwars as seen in the TMI-2 centerline slump cavity. The centerline to edge process may not be as severe in a spent fuel pool as in a more densely packed reactor vessel. It is possible that melting of steam spacer plates could occur starting from the top of the bundle. Your scenario has three complications. It postulates that tremperatures would be limited to a 300 degree range. It seems to assume that the spacers could all be melted on a bundle before the cladding itself has ruptured at the top of the rods. And it still depends on some way that the cooler channel can be removed from embrittled unsupported fuel rods (once spacer plates are gone) in some form without shattering the rods.

If the pictures showed partial bundles or debris that didn't have other possible explanations, I would agree But to believe that an 800 pound bundle could be lifted in an explosion, stripped of its channel and spacer plates and dropped onto a pile of debris without breaking into random lengths, strains my understanding of fuel damage processes.

I wish we had some better way of comparing the diameter of the pictured "fuel rods" than eyeballing it to the FHM handrails, but I still think those "rods" are too large to be fuel.

 

[|Fred]

I think that the soundtrack should in deed be weighted with a low reliability factor...
We just need to identify who toke the video and ask him..

 

[NUCENG]

Hydrogen is generated in a corrosion reaction between Zircaloy and water at 300°C. The higher the temperature, the faster the reaction. To have a hydrogen explosion, one only need H₂ + O₂ with something like a 15% concentration. Below that one gets a fast burn or deflagration.

Also, one doesn't necessarily need O₂ as the oxidizer for a hydrogen explosion. Chlorine gas (Cl₂) mixed with H₂ makes for a pretty good explosion. If there was H₂ produced from the Zr + 2 H₂O => ZrO₂ + 2H₂ reactions, and seawater release Cl₂, then I wonder if an H₂ + Cl₂ => 2 HCl reaction in the top of the RPV would be possible.

If my timeline is right, the injection of seawater to the reactors started after the explosions. Chlorine is now more of a concern if more hydrogen is being generated.

I just saw #3081. Okay now we have a clear difference which may be important between Unit 1 and the sequence for units 2,3. So far we have been looking for common cause for units 1,2, and 3. Maybe we have three or even four different accidents to study.

 

[NUCENG]

I don't think the fuel handling machine even goes past the reactor containment to the equipment pool, does it? And that being the case, then the overhead crane would be needed to transfer fuel rods, but than only happens after fuel rods have been put in casks. So, even if they wanted to get the fuel rods into the equipment pool, I can't see how they would do it.

You are right to the best of my recollection.

In the US plants reaching the point where the fuel pool was nearly full still needed to be able to offload a full core if vessel internal repairs were needed. Some plants had customized racks built to put in the cask pool temporarily. This could not be a permanent rack because it would prevent cask operations that would eventally be needed. There also may be designs that allow new fuel to be in a different designated region. I just don't know of any two tier or different depth storage of spent fuel.

 

[M. Bachmeier]

REGARDING COMPRESSION ARTIFACT AND RESOLUTION

Just for grins, here are the actual pixels I am able to resolve, not from the video, but from the links to the frame grabs I posted. ROI is the initial white puff and red fire ball.

http://i306.photobucket.com/albums/nn270/tcups/Fukushima%20Foto%20Files/Picture2-1.png

http://i306.photobucket.com/albums/nn270/tcups/Fukushima%20Foto%20Files/Picture3-1.png

http://i306.photobucket.com/albums/nn270/tcups/Fukushima%20Foto%20Files/Picture4-1.png

Not great, but more than 8 pixels for sure. Plus the tower just to the left will give an idea of edge artifact and contrast resolution.

Those are not artifacts. And it looks like a pocket explosion of rapidly ejected gas.

 

[TCups]

I triangulated the camera location for the explosions to be around 3-4 miles SW (~53 degrees) of building 4 (or ~58 degrees of building 7). I calculated the building angles with respect to the camera using the relative widths of the projections of the south and west walls on the image compared to their actual proportions (about 3/4) and used the distance between the buildings (~3500 ft). The camera is 15000-17000 ft south and 11000-13000 ft west of building 4. I can't spot any of the features shown in the explosion videos on google Earth around that location, maybe someone can figure it out or refine/check the calculations?

Can't do the calculations any more, but I can tell you that Bldg 4 probably isn't in the picture. What at first glance appears to be Bldg 4 is a different building in the foreground. Key on the 3 towers for your triangulation.

|Fred's assessment of the resting spot of FHM3 is quite accurate, I think. As usual, his observations have been very accurate and helpful.

I am fast approaching or perhaps well past my ability to comment with authority on any of the potential artifacts in the video(s), but one last observation:

The visible camera jiggle from the shock waves arrives after the visible blasts, particularly blasts 1 and 2, if my observation is correct. A reasonably accurate estimation of the distance from B3 (or the tower between B3 and B4 to the location of the camera site plus the speed of sound in air at sea level should give the appropriate time delay needed to allow someone with more video skills than me to overlay the soundtrack to the video in real time and make matching the blast sounds and transient metal sounds with the video less susceptible to errors of interpretation.

If the three explosion sounds were added by the video producers, then they sure as hell went to a lot of trouble to add the transient metallic and swooshing sounds that razzz (I believe) first pointed out. And on more careful consideration, there is no ring-down diminution of amplitude of the blast sounds as would be expected from a series of echoes.

 

[georgiworld]

1st post so hello.
Quote from the site "This is the (bitmap) PDF file of the NRC assessment obtained supposedly from a source outside the government. This material was cited by a New York Times report (U.S. Sees Array of New Threats at Japan’s Nuclear Plant,"
http://fukushimafaq.wikispaces.com/Miscellaneous"

Thank you for the great, well-organized site. Are you the author?

 

[Astronuc]

I just saw #3081. Okay now we have a clear difference which may be important between Unit 1 and the sequence for units 2,3. So far we have been looking for common cause for units 1,2, and 3. Maybe we have three or even four different accidents to study.

Yes - there are 4 different, but similar and related events. Unit 4 seems to be primarily the SFP - what happened there. Besides going dry, is there structural failure?

Units 1, 2 and 3 all evolved differently. One of the big unknowns is the structural damage done by the earthquakes. We don't know if and which pipes and structures might have cracked or broken. That would affect water levels.

Unit 1 upper containment failed quickly (within about 24 hrs) of loss of coolant, ostensibly due to hydrogen from the core which exploded - and well before seawater was introduced.

Unit 3 suffered a hydrogen explosion after the injection of seawater. The apparent RST assessment indicates that seawater in the core leads to enhanced hydrogen production.

Unit 2 seems to have had some explosion or major structural failure within containment, and it is leaking contaminated water to the ocean, or at least to the outside of containment.

Units 1, 2 and 3 are similar in nature - LOOP followed by LOCA, followed by loss of containment - but three different paths.

 

[georgiworld]

Very interesting compilation of webcam images synchronized and timed.

 

[artax]

Thank you for the great, well-organized site. Are you the author?

That site has the best rew video I've seen of reactor 3 but no sound?



best from 22 seconds.
and this might be raw colour one.

http://www.youtube.com/user/thegermanfire#p/u/28/tvJ6VBlkqfs

 

[|Fred]

How do they inject water into 1 and 2 pool ?
There is a vertical structure linking the floors : the lift( and likely a staircase) could it play a role in the lower floor damages ?

 

[Astronuc]

How do they inject water into 1 and 2 pool ?
There is a vertical structure linking the floors : the lift( and likely a staircase) could it play a role in the lower floor damages ?

For Unit 1, the METI/NISA-JNES presentation indicates injection of water through the fire extinguisher system and water sprayed by truck. It's not clear that is still the case, but perhaps they lost the cooling system in Unit 1.

In Unit 2, they are using a motor operated pump with water from the fire extinguishing system.

There could be leaking water over the floor or through any cracks that might have occurred in the SFP steel liner and concrete structure.

 

[tsutsuji]

French scientists simulate how the radioactivity dilutes into the Pacific Ocean : http://sirocco.omp.obs-mip.fr/outils/Symphonie/Produits/Japan/SymphoniePreviJapan.htm
See also the simulation after 72 days on page 8/9 of http://www.irsn.fr/FR/Actualites_pr...ident-Fukushima-sur-milieu-marin_04042011.pdf