Japan Earthquake: Nuclear Plants at Fukushima Daiichi

In summary: RCIC consists of a series of pumps, valves, and manifolds that allow coolant to be circulated around the reactor pressure vessel in the event of a loss of the main feedwater supply.In summary, the earthquake and tsunami may have caused a loss of coolant at the Fukushima Daiichi NPP, which could lead to a meltdown. The system for cooling the reactor core is designed to kick in in the event of a loss of feedwater, and fortunately this appears not to have happened yet.
  • #701
antonl said:
[PLAIN]http://www.faz.net/m/%7b7ae28c3d-c2a2-4b40-8e20-c536525a2b69%7dpicture.jpg

todays fire in reactor 3

omg.
 
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  • #702
Playbook said:
About the usage of seawater and the problems it creates:Now the Pacific Ocean has an average salt content of a 35 g / 1000 g of water
We assume that the reactor evaporates 2000 g (2 litres) water / second

therefore:

2 kg/s * 3600 s * 24 * 7 * 0.035 = ~42 tons per week or 6 tons a day !

That's definately a big issue at the moment. Could it be that the smoke coming out is from burning salt?

Salt melts at 801 degrees C and boils at 1413 degrees C
 
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  • #703
FYI from http://www.telegraph.co.uk/news/worldnews/asia/japan/8394963/Japan-nuclear-crisis-fears-over-food-contamination.html" By Nick Allen, in Tokyo 10:09AM GMT 21 Mar 2011
Engineers have managed to rig power cables to all six reactors at the Fukushima complex, and restarted a water pump that will help reverse the overheating that triggered the world's worst nuclear crisis in 25 years.

Some good news...

Rhody...
 
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  • #704
I think that the smoke from number 3 could be related to the ongoing electrical hookup. May be a piece of damaged equipment caught fire when they tried to power it back up with the newly run electrical line. All just speculation on my part and no links.
 
  • #705
AntonL said:
Salt melts at 801 degrees C and boils at 1413 degrees C

So, if the 6 tons of salt per day is at 801ºC or higher, it is a liquified, and above 1413ºC, it is vaporized. Either way, doesen't that mean it will either flow out of the primary containment into the torus pool, or vaporize rather than "burn"? And what does "burning" salt form? NaCl + O2 <=> ? What is the heat of transition for NaCl? Could melting or vaporizing salt, in fact, be a better coolant than pure water in that respect?

I can't get my arms around lots of dark smoke having something to do with ocean salt. I guess that shows.
 
  • #706
rhody said:
FYI from http://www.telegraph.co.uk/news/worldnews/asia/japan/8394963/Japan-nuclear-crisis-fears-over-food-contamination.html" By Nick Allen, in Tokyo 10:09AM GMT 21 Mar 2011 Some good news...

Rhody...

mattm2 said:
I think that the smoke from number 3 could be related to the ongoing electrical hookup. May be a piece of damaged equipment caught fire when they tried to power it back up with the newly run electrical line. All just speculation on my part and no links.

First IR image released in news broadcast
Heat.jpg


Rhody and Mattm2 - sorry to put a damper in your optimism
Electrical hookup would be in the control buildings to the east of the plant, we will see many days pass before the first cooling pump will work.

Hot spot over spent fuel pools indicated as 128 deg C and multiple hot spots at other places
(at the moment I cannot listen to the broadcast - only watch so no idea what they saying
 
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  • #707
FYI, Not verified and appears to be a not for profit:

"/www.allvoices.com/contributed-news/8482842-website-monitors-radiation-levels-across-united-states-map"[/URL]
[QUOTE]A National Radiation Map that depicts environmental radiation levels across the United States is available on the home page of the Radiation Network. It is updated in real time every minute. Not a government site, this website claims to be the first where "the average citizen (or anyone in the world) can see what radiation levels are anywhere in the USA at any time."
Mineralab, LLC, who operates the website from Prescott, Arizona, cautions that it is unable to independently verify that the radiation levels or any radiation alerts that are displayed on the Radiation Map are correct and valid. Monitoring stations are operated by grassroots volunteers. Geiger counter malfunctions or proximity of the counters to certain medical procedures or to radioactive items can cause high readings to occur.
It appears from the map that there are nine monitoring stations currently functioning. The map indicates that they are located in Washington, California, Arizona, Colorado, and Indiana with two additional stations on the East Coast.
The public is invited to join the effort. This requires a digital Geiger counter, Software available from Radiation Network, a computer with Windows operating system, and direct internet access.
Active participants receive the benefit of a map that is fully interactive: with zoom capabilities; descriptions of nuclear sites and monitoring stations; additional map layers, including counties, airports, roads, railroads, lakes and rivers; and the capability to download city streets for their home county. The software also entitles the user to participate in the network's own chat forum.
[/QUOTE]

For what it is worth... not to be alarmist, just informed...

Rhody...
 
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  • #709
Heat.jpg


Those IR pictures seems to rule out some of Tcups hypothésis , if Spend fuel Rod were dispersed on site they would heat up and show.
 
  • #710
mattm2 said:
I think that the smoke from number 3 could be related to the ongoing electrical hookup. May be a piece of damaged equipment caught fire when they tried to power it back up with the newly run electrical line. All just speculation on my part and no links.

I think this is the best working hypothesis on the nature of the fire. I would think the electrical system would have been damaged at some point in this whole fiasco. Perhaps some salt water came into contact with a portion of the wiring, causing a short?
 
  • #711
|Fred said:
Heat.jpg


Those IR pictures seems to rule out some of Tcups hypothésis , if Spend fuel Rod were dispersed on site they would heat up and show.

Do you mean the picture of the newscaster with the screen behind him? Is there another source of more meaningful IR imagery?
 
  • #712
|Fred said:
Heat.jpg


Those IR pictures seems to rule out some of Tcups hypothésis , if Spend fuel Rod were dispersed on site they would heat up and show.

We only see reactor 3, reactor 4 is to the left of the picture
 
  • #713
TCups said:


OK, Oyester Creek, but then I have to assume that the most identifiable feature in the Fukushima building after the blast -- the intact square hole where the fuel casks are lifted by the crane, has been cut away from this drawing, correct?

Also, a small portion of the gate connecting the primary containment to the SFP is shown near the bottom of the transfer channel or "chute". If the scale is correct, it greatly reinforces my contention that the path of least resistance of a blast originating in the primary containment, outside of the RV would be through that gate (even if there are 2 of them, which does not appear to be the case) rather than out the top of the plug.

Notice the design. It appears to me that the logic behind a relatively thin-walled (concrete+ steel, or steel?) gate is that there is a large volume of water behind it, which under normal conditions, would tend to greatly reinforce the backside pressure on the gate at that point. If so, then here is another major design flaw. The reactor containment is compromised if the spent fuel pool is more than a few feet low on coolant. I suspect that the original designers considered an empty SFP with a hot reactor an unthinkable event. If so, then they should re-think that one.

Also, it occurs to me that if the overhead crane were parked at the north end of the building, it's weight would tend to bend the north end wall inward if the south, east and west walls were blown out, accounting for the under-folded north wall girders in our current pictures of Unit 3.

My conclusion:
Loss of water in the SFP greatly compromised the integrity of the reactor containment and the containment of the rods in the SFP when hydrogen and oxygen gasses in the reactor containment exploded. The dark smoke in the latest news release is ominous. I now fear that they may now have lost both the reactor core and the primary containment.


Someone please refute that.

The SFP has no significant structural association (to my knowledge) with the reactor's primary containment and surely not the Reactor Vessel that would lead to such a speculation.

Some causation thoughts: Due to the heavy seismic activity the primary containment (concrete) may have been compromised by sheared pipe lines and pneumatic seals on the top of the primary containment. The SFP is an independent system (piping and construction) as you can see from the drawings. Even with the access gates open it does not have to be further flooded to protect the spent fuel. Flooding the primary containment with sea water to externally cool the reactor vessel and its contents will definitely lead to a big and smelly mess within the primary containment. It is not known whether or not the reactor vessel has experienced a large break LOCA, but something has caused the reactor vessel water level to decrease and is surely the effects of trying to control RPV pressure via venting to the Primary Containment with no make up water to the RPV. The station is in a "black out" situation (no electrical power) that effectively stops all but the manual operation of valves (if they are so equipped). I believe venting of the RPV to the Primary Containment is automatically initiated on over pressurization, akin to your home water heater, but a little more complicated. Steam from venting would normally condense in the Suppression Pool and be pumped back to the RPV (alas no power for the pumps). Venting of accumalated gaes from the Primary Containment is by seepage or open valves (or blast damaged piping and valves), since the Stand-bye and normal off-gas system pumps are basically isolated or shutdown. I noted that TEPCO decided to cut holes in some of the reactor buildings to prevent buildup of explosive gases, which indicates to me they have very little control over the venting of the Primary Containments and the avenue of releases. Reactor relief valves have a limit on their ability to reset and contain pressures due to continued recycling, high temperature water and steam flows affecting their valve seats and springs. Sticking relief valves is not new stuff to the industry.

I do not understand why they have not established a continuous and remotely operated fogging spray over the reator buildings emitting steam and smoke to reduce the plume effects of offsite releases.

Just some idle thoughts. Won't know the whole story until events, actions and results sifted through, and are published in the future.
 
  • #714
TCups said:
Heat.jpg

Do you mean the picture of the newscaster with the screen behind him? Is there another source of more meaningful IR imagery?

Yes I marked the area of the picture below you will now be able to correlate features, like the vent pipe of reactor 4 to exhaust stack at top right hand corner and the pipes running North south along the turbine holes at bottom of IR pic. Just follow the green lines.
The most intense temp is south east corner of reactor 3
Sorry -I have not found a released version of the IR picture so we only have above when I did a quick screengrab when I saw on my PC.
heat5.jpg
 
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  • #715
mattm2 said:
I think that the smoke from number 3 could be related to the ongoing electrical hookup. May be a piece of damaged equipment caught fire when they tried to power it back up with the newly run electrical line. All just speculation on my part and no links.

If that were the case Tepco would be aware of the cause. At this time Tepco claims to be unaware of the cause. They further claim to be investigating. If spent fuel was burning, air samples should detect the different isotopes from spent fuel rods, yes?
 
  • #716
AntonL said:
Yes I marked the area of the picture below, the most intense temp is south east corner of reactor 3
Sorry -I have not found a released version of the IR picture so we only have above when I did a quick screengrab when I saw above.
heat1-1.jpg

Sorry, Anton -- I just can't seem to get oriented to the IR image and don't have a lot of time just now. The two pipes at the bottom of the color image are the steam pipes between the reactors and the turbine bldgs. one of the pipes should have a break. I can't see enough detail to make any conclusion without a lot more study. Later.
 
  • #717
TCups said:
Sorry, Anton -- I just can't seem to get oriented to the IR image and don't have a lot of time just now. The two pipes at the bottom of the color image are the steam pipes between the reactors and the turbine bldgs. one of the pipes should have a break. I can't see enough detail to make any conclusion without a lot more study. Later.

Appologies TCups and others I had finger problems in uploading the picture with yellow box showing area covered by IR picture and green lines connecting common features as aid to orientation, please see my https://www.physicsforums.com/showpost.php?p=3200820&postcount=717" with correct orientation aid or just scroll up two posts
 
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  • #718
[PLAIN]http://img194.imageshack.us/img194/2929/fukushimair2.png [PLAIN]http://img31.imageshack.us/img31/4564/fukushimair1.png

Here are screen grabs from a high-quality NHK World stream. Original picture size, cropped with pixel-accuracy. From memory the translation said the hotspots are around 120°C.
 
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  • #719
OK, so the image is tightly cropped on reactor unit 3. The region of the smoke plume is extremely hot. There are scattered heat signatures in the remainder of the reactor bldg. I can't really conclude much about the remainder of the debris field(s) without a larger FOV and it is not clear what the window/level setting of the IR imagery is, but presumably it would be set to find something as hot as an exposed fuel rod.

So far, I don't seen any contradiction to the containment explosion with blast of fuel rods and perhaps some scattered fragments of fuel rods outside of the FOV. But we are drawing conclusions of a picture of a TV picture at low resolution.
 
  • #720
TCups said:
OK, so the image is tightly cropped on reactor unit 3. The region of the smoke plume is extremely hot. There are scattered heat signatures in the remainder of the reactor bldg. I can't really conclude much about the remainder of the debris field(s) without a larger FOV and it is not clear what the window/level setting of the IR imagery is, but presumably it would be set to find something as hot as an exposed fuel rod.

They said that they used this IR footage to conclude the temps in the SPF of unit three is 128 degree c (IIRC). So the white areas would be around that temperature.

There's a bit too much speculation going on in this thread without any real basis at the moment, imo.
 
  • #721
TCups said:
So far, I don't seen any contradiction to the containment explosion with blast of fuel rods and perhaps some scattered fragments of fuel rods outside of the FOV. But we are drawing conclusions of a picture of a TV picture at low resolution.

An analysis expecting damages on the SPF structure after the explosion on #3.
From the french institude for nuclear safety. (IRSN)
Link (french document) : http://www.irsn.fr/FR/Actualites_pr...Seisme-Japon_Point-situation-20032011-06h.pdf

L’IRSN estime que la dalle anti-missile située à la verticale de la cuve et de l’enceinte de
confinement a dû être détruite lors de l’explosion hydrogène du 14 Mars 2011. Si les ouvrages qui supportent cette dalle ont également été touchés, il est envisageable, outre les fuites éventuelles, que le niveau d’eau maximal possible au dessus des assemblages combustibles entreposés dans la piscine soit diminué (dans le pire cas : 1 mètre au dessus du haut des assemblages). Ceci expliquerait les débits de dose très importants au droit du bâtiment et confirmerait les efforts pour maintenir en eau cette piscine.


Pool of reactor No. 3
IRSN believes that the missile proof slab located vertically above the vessel and the containment (see Annex 1) has been destroyed by the hydrogen explosion of the 14th of March 2011. If the structures that support this slab were also affected, it is conceivable that the possible maximum water level above the fuel assemblies stored in the pool would be reduced (in the worst cases: 1 meter above the top of the assemblies). This would explain the very high radiation levels to the top of the building and the constant efforts needed to maintain water level in this SPF.
 
  • #722
"They", et al? 128ºC? Above the boiling point of water? In the spent fuel pool? I 'spec steam could be 128ºC, but not water in a pool, but I would need to know if any steam was rising when this image was obtained.

Also, if the window/level of the color IR spectroscopy were set at a "white" level =128ºC = hottest thing in the image, then I 'spec that everything above 128ºC would also be white, but I don't know the window/level of the color image or what parameters they used to measure the true temperature of the SFP, or even if the hottest thing on the image is what is being measured as the SFP temp. Not enough information in that single image. I do know were it looks hottest now, though, both in Bldg 3 and 4. And I do know that Bldg 3 is hotter than Bldg 4, apparently right where the smoke/steam seemed to be venting after the explosion and where my earlier 'spec was that it was the most likely site where a defect in the primary containment might occur after an explosion. I also 'spec that it wasn't hot "corium" that was seen hanging out the hole on the 3-side of Unit 4.

But you know what the constipated fly said, right? -- "I spec not."

Sorry if I speculate too much. Apologies.
 
  • #723
TCups said:
"They", et al? 128ºC? Above the boiling point of water? In the spent fuel pool? I 'spec steam could be 128ºC, but not water in a pool, but I would need to know if any steam was rising when this image was obtained.

Also, if the window/level of the color IR spectroscopy were set at a "white" level =128ºC = hottest thing in the image, then I 'spec that everything above 128ºC would also be white, but I don't know the window/level of the color image or what parameters they used to measure the true temperature of the SFP, or even if the hottest thing on the image is what is being measured as the SFP temp. Not enough information in that single image. I do know were it looks hottest now, though, both in Bldg 3 and 4. And I do know that Bldg 3 is hotter than Bldg 4, apparently right where the smoke/steam seemed to be venting after the explosion and where my earlier 'spec was that it was the most likely site where a defect in the primary containment might occur after an explosion. I also 'spec that it wasn't hot "corium" that was seen hanging out the hole on the 3-side of Unit 4.

But you know what the constipated fly said, right? -- "I spec not."

Sorry if I speculate too much. Apologies.

As long as your looking for answers and not drawing unfounded conclusions your contributing to understanding. The problem is that much of the information needed exists but is not being provided.

I don't know why we have an international watchdog if it doesn't bark loudly when pertinent information is withheld from public scrutiny.
 
  • #724
ndray said:
An analysis expecting damages on the SPF structure after the explosion on #3.
From the french institude for nuclear safety. (IRSN)
Link (french document) : http://www.irsn.fr/FR/Actualites_pr...Seisme-Japon_Point-situation-20032011-06h.pdf

L’IRSN estime que la dalle anti-missile située à la verticale de la cuve et de l’enceinte de
confinement a dû être détruite lors de l’explosion hydrogène du 14 Mars 2011. Si les ouvrages qui supportent cette dalle ont également été touchés, il est envisageable, outre les fuites éventuelles, que le niveau d’eau maximal possible au dessus des assemblages combustibles entreposés dans la piscine soit diminué (dans le pire cas : 1 mètre au dessus du haut des assemblages). Ceci expliquerait les débits de dose très importants au droit du bâtiment et confirmerait les efforts pour maintenir en eau cette piscine.


Pool of reactor No. 3
IRSN believes (speculates?) that the missile proof slab located vertically above the vessel and the containment (see Annex 1) has been destroyed (vaporized? shattered? popped off like a giant cork?) by the hydrogen explosion (where?) of the 14th of March 2011. If the structures that support this slab were also affected (the side of the SFP where the gate to the transfer chute is?), it is conceivable (one could speculate) that the possible maximum (maximum? - interesting choice of words) for water level above the fuel assemblies stored in the pool would be reduced (in the worst cases: 1 meter above the top of the assemblies). (if the earthquake didn't slosh it out like this morning's coffee at the speed bump, and if the shock wave of the blast that destroyed the missile proof plug didn't spill any more, and if the only leakage from the pool was at a level no lower than the transfer chute, and if all the dumping and spraying done before the radiation levels rose too high helped before too much more boiled off at 128ºC?) This (and only this?) would explain the very high radiation levels to the top of the building and the constant efforts needed to maintain water level in this SPF.

You may be right about the speculation thing after all. I am sorry, everyone. It is my nature. I just can't help myself sometimes. I will try do better. I promise.
 
  • #725
M. Bachmeier said:
As long as your looking for answers and not drawing unfounded conclusions your contributing to understanding. The problem is that much of the information needed exists but is not being provided.

I don't know why we have an international watchdog if it doesn't bark loudly when pertinent information is withheld from public scrutiny.

http://mdn.mainichi.jp/mdnnews/news/20110319p2a00m0na005000c.html" published on 19th the following "The footage taken from an RQ-4 Global Hawk drone was passed on to the Japanese government with permission for public release from the U.S. Air Force. U.S. military sources said that the decision to release the footage -- or not -- was up to the Japanese government." Although published on 19th it is still the No1 article read on the 21st

The USA has every opportunity to release information but refrains. I am pretty sure watchdog officials also have this footage and expert analysis thereof but are bound to diplomatic secrecy.

TCups said:
You may be right about the speculation thing after all. I am sorry, everyone. It is my nature. I just can't help myself sometimes. I will try do better. I promise.
TCups you are doing very well, no need to change
 
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  • #726
AntonL said:
An http://www.slideshare.net/iaea/4-briefing-radiation-protection-20-03-2011a" regarding radiation levels

and

ongoing http://www.mext.go.jp/english/" published by Japanese government.

The IAEA lists 15 kBq per kg of iodine-131 in spinage and up to 6100 Bq/kg in spring onions from Ibaraki prefecture.

Those are levels to worry about. Agriculture in the region seems impossible this year.
 
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  • #727
PietKuip said:
The IAEA lists 15 kBq per kg of iodine-131 in spinage and up to 6100 Bq/kg in spring onions from Ibaraki prefecture.

Those are levels to worry about. Agriculture in the region seems impossible this year.


Iodine does have a half-life of 8 days. It will be gone quite rapidly. 15kBq isn't THAT much radiation.
 
  • #728
I propose some modifications (in bold) to translation initially posted by ndray:
ndray said:
IRSN speculates that the missile proof slab located vertically above the vessel and the containment (see Annex 1) has been shattered then scattered by the hydrogen explosion (where?) of the 14th of March 2011. If the structures that support this slab were also affected (the side of the SFP where the gate to the transfer chute is?), it is conceivable (one could speculate) that, besides possible cracks, the possible maximum (maximum? - interesting choice of words) for water level above the fuel assemblies stored in the pool would be reduced (in the worst cases: 1 meter above the top of the assemblies).
Note: This is not about the water level in this pool, this is only about the water capacity of the pool after some of its walls have been curtailed by the fall of this shattered and scattered slab and support.
ndray said:
[continued]
This would be sufficient to explain the very high radiation levels close to the building and the significant and constant efforts needed to maintain water level in this SPF.
TCups said:
You may be right about the speculation thing after all. I am sorry, everyone. It is my nature. I just can't help myself sometimes. I will try do better. I promise.

Maybe the information here is about the presence of thick slab pillar(s) just near the walls of this pool.
 
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  • #729
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  • #730
dgdd said:
I propose some modifications (in bold) to translation initially posted by ndray:

Note: This is not about the water level in this pool, this is only about the water capacity of the pool after some of its walls have been curtailed by the fall of this shattered and scattered slab and support.



Maybe the information here is about the presence of thick slab pillar(s) just near the walls of this pool.

Where?
http://img863.imageshack.us/img863/3206/reactor.jpg
 
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  • #731
myth_kill said:
link is not working

Sorry. I will try later. OP with faulty links deleted. Lots of folks must have been looking. Bandwidth exceeded.

OK, try again.

If the fuel transfer chute and gate (yellow) were the weak spot. A blow out here would cause a blast from inside the primary containment to blow out and up from the south end of the building, blow out the roof over the south end, and if the heavy crane (blue) partially shielded the north wall, perhaps collapse it inward with portions of the roof girders over it. Venting stem would come from the region of the chute.
 

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  • #732
Those IR images are interesting. Why are there hotspots on the ground between 3 & 4? What are the cause of those hotspots? Very interesting.
 
  • #733
The four-reactor Fukushima II Daini plant was just 7 miles due south of the Fukushima I Daiichi plant. It was on the coast just like the Daiichi plant, was hit by the same earthquake and Tsunami, and to my knowledge is of similar design.

Why was it not as badly affected?
 
  • #734
rhody said:
FYI: For perspective:

http://www.cnbc.com/id/42112536?slide=1"

Rhody... :redface: (no dark humor intended, the red face that is... well maybe, just a little)

Tokaimura 1999, wasn't TEPCO involved?
Goiania, Brazil 1987, that blue barbeque scene, is that where the expression "laughing in the face of death" came from?
More horrible than horror stories these accidents. Sobering knowledge. We learn from our mistakes, yes, but some mistakes are incomprehensably awful.

Accidents will happen. I accept that.
Playing with fire this is not, I accept that also.
It's the cover-up reflexes and twisting of numbers afterwards that I find most depressing.
 
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  • #735
joema said:
The four-reactor Fukushima II Daini plant was just 7 miles due south of the Fukushima I Daiichi plant. It was on the coast just like the Daiichi plant, was hit by the same earthquake and Tsunami, and to my knowledge is of similar design.

Why was it not as badly affected?

Nuclear PR is familiar with the phrase 'freak accident', Daini (= Plant 2 in Japanese) experienced freak luck.

Seen that slowed-down video footage from the helicopter over Daiichi? Early on you see tarmac ripped like paper by the earthquake. A metre away and it's still intact. Earthquake causes local surface damage over a great many locations. Hope this unscientific explanation helps.
 

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