Japan Earthquake: Nuclear Plants at Fukushima Daiichi

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The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #4,321
MJRacer said:
Exactly. The drywell appears to be completely gone and it appears as if we are looking right at the stainless steel reactor vessel (sans yellow cap).

No, not exactly. I'm saying your observation is wrong. This isn't a part of the drywell. And it's surely not a part of the pressure vessel. AND the yellow cap isn't part of the pressure vessel, either, it's part of the drywell/containment.
 
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  • #4,322
MJRacer said:
I have marked in red the part of the drywell that seems to have been blown away. But, if so, how?!

In your first picture you can see the drywell cap in the background (yellow). It is sitting on the floor of the refueling level in the reactor building. That floor is several meters above the top of the drywell cap when it's in place. There is no part of the reactor or drywell vessel high enough to block the view of the yellow cap when it's removed and on the floor.

As for the second and third pictures, at that point in construction the reactor vessel would not be in place yet. The middle picture shows the upper part of the drywell sticking up out of the construction site. Whatever the bulky thing in the top picture is, it's not part of the drywell or reactor vessel.
 
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  • #4,323
Everything is not totally wasted. Things could be worse, another good sized earthquake could finish off SFP 4 or even cause more junk to fall into it including the other pools. It flood and bleed for now, I don't think corium is traveling freely as the flooding along with nitrogen injection is preventing Unit 1 from freaking out again. 2 & 3 sitting might as well be sitting in a overflowing swimming pools but with such high contamination readings you can't do any meaningful work on any of them until they cool down.

TEPCO seems the most worried about Unit 4's pool so you know where their head is at.

They need to convert a Bobcat simulator(s) to real-time viewing/controls and keep cleaning up using remote operators before attempting the big stuff. If they can keep the contamination mostly localized anything escaping will hopefully just dilute in the air and water. Just don't need any more big event's.

I notice the think tank on this forum is pretty much silent and they are in the industry so they might know more than they are willing to say. Can't blame'em.
 
  • #4,324
MiceAndMen said:
In your first picture you can see the drywell cap in the background (yellow). It is sitting on the floor of the refueling level in the reactor building. That floor is several meters above the top of the drywell cap when it's in place. There is no part of the reactor or drywell vessel high enough to block the view of the yellow cap when it's removed and on the floor.

As for the second and third pictures, at that point in construction the reactor vessel would not be in place yet. The middle picture shows the upper part of the drywell sticking up out of the construction site. Whatever the bulky thing in the top picture is, it's not part of the drywell or reactor vessel.

Thanks and in reply to all, I see that now. My apologies for the bandwidth.
 
  • #4,325
razzz said:
I notice the think tank on this forum is pretty much silent and they are in the industry so they might know more than they are willing to say. Can't blame'em.

No I think they just decided to finally get some sleep. Now if the tornadoes would just go away I could get some sleep too.
 
  • #4,326
MJRacer said:
The object I have circled in red looks like it is round and does not appear to be in the corner, but away from both walls a certain distance.

Here is appears to be a picture of the control room:

just take away that pilar holding it up and turn it sideways, voilá.
 
  • #4,327
MJRacer said:
Thanks and in reply to all, I see that now. My apologies for the bandwidth.

No problem, we're all just trying to understand what all the pictures, videos and assorted other data are showing.

M. Bachmeier said:
No I think they just decided to finally get some sleep. Now if the tornadoes would just go away I could get some sleep too.

Stay safe.
 
  • #4,328
I_P said:
This article from Asahi lays some of it out:
http://www.asahi.com/english/TKY201104190193.html"
The "puddles" are 5 meters deep now:
"Officials of the Nuclear and Industrial Safety Agency (NISA) said April 18 that a pool of water about five meters deep had been found in the basement of the building housing the No. 4 reactor.

Radiation levels as high as 100 millisieverts per hour were detected on the water's surface.

About 54,000 tons of radiation-contaminated water also sits in the basements of the turbine buildings for the No. 1 to No. 3 reactors.
"

And that is where the missing radioactivity of the Unit 4 SFP went.
 
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  • #4,329
It is inside picture of the Kariwa Tepco Power plant Fuel pool taken by a security camera before and after the Niigata-Chuetsu-Oki Earth quake in 2007
http://www.tepco.co.jp/en/niigata/plant/jisho02-e.html
[URL]http://www.tepco.co.jp/en/niigata/plant/images/jisho02/k3001.jpg[/URL]
[URL]http://www.tepco.co.jp/en/niigata/plant/images/jisho02/k3002.jpg[/URL]

Tepco building seems so be strainer when in comes to holding water..
on the above occasion watter steered out of the out the pool found its way to the ocean..
[URL]http://www.tepco.co.jp/en/niigata/plant/images/jisho04/k6003.jpg[/URL]
http://www.tepco.co.jp/en/niigata/plant/jisho04-e.html
 
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  • #4,330
TCups said:
<..>The stuff on the facade of the turbine building is laying over the edge, not damage from an outward blast. The smoke that looks to be coming from the east side of Bldg 4 is coming from the stack I guess. And the debris are from Bldg 3. So, BTTDB . . .

The 'smoke' is not smoke it is steam. We know #3 had puked up just a few minutes ago. We know that _a larger area_ around it must have been soaked by water from it. Hot water. So, no surprise, we see steam coming from that area...

But soon that steam dissipated. Webcam about an hour later:
20110314120021.jpg


I'm not even sure one can see, that it is still smoking a bit from the top of unit 3, but it did.
 
  • #4,331
rowmag said:
Looks like they found a leaking fuel assembly. See page 26:
http://www.tepco.co.jp/nu/f1-np/press_f1/2008/pdfdata/bi8a09-j.pdf

Would something like that have been left in the SFP after replacement, or would it have been stored in isolation somewhere else?

Following up to myself: From page number 8 (PDF page 10) of http://www.tepco.co.jp/nu/f1-np/press_f1/2008/pdfdata/bi8a08-j.pdf, they report that a suspected leaking fuel assembly in the core had been identified during operation in 2007, I gather by sliding different sets of control rods in and out with the plant running at reduced output until they managed to get the leaked radioactive gas to stop being produced. They isolated that assembly by inserting the control rods around it, and went back up to full power until the scheduled maintenance/inspection period in 2008. When they eventually pulled the suspect assembly out, it showed no visible signs of damage, but they treated it as a spent fuel assembly and did not re-use it.

Which doesn't exactly answer my question, but perhaps suggests it was placed into SFP4?

(Not sure this tells us anything, though, unless it gives NUCENG some bright idea...)
 
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  • #4,332
TCups said:
Building 4 has already exploded. Two panels have blasted out of the east side and impacted on the west facade of the turbine building for Unit 4, and smoke is pouring out of the east side of Building 4. Your eyes aren't looking for it because you know this is "before" the explosion. But the impacts on the turbine building are real. They weren't there before the explosion.

https://www.physicsforums.com/attachment.php?attachmentid=34633&d=1303253626

after the https://www.physicsforums.com/showpost.php?p=3255144&postcount=4231", it's what i saw 5 minutes later , analyzing the possible trajectories. You can see on the pipe, there is the blue color of the wall attached to the cement, that can't come from the reactor 3. But, if you look well, the edge of building in front of the reactor 4 was already broken before the "possible explosion" of reactor 4
 

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  • #4,333
Krikkosnack said:
after the https://www.physicsforums.com/showpost.php?p=3255144&postcount=4231", it's what i saw 5 minutes later , analyzing the possible trajectories. You can see on the pipe, there is the blue color of the wall attached to the cement, that can't come from the reactor 3. But, if you look well, the edge of building in front of the reactor 4 was already broken before the "possible explosion" of reactor 4

Your yellow trajectories don't take into account visible tracks on the turbine building roof - it looks like whatever felt through the roof to the inside of the building was first sliding and didn't get through till it slowed down enough.
 
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  • #4,334
NUCENG said:

Thank you very much, it worked. :)@TCup

As for the bldg 4 "explosion before the explosion" - I mentioned nearly the same a couple of days ago... ^^

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

This image was taken on March 14th - but I don't know the exact time zone and the exakt time. Sources report an explosion in Unit 4 in March 15th, 6am, which destroyed two panels - that's consistent with your observation on this sat image.
If the satellite was taking images at US standard time, it's over half a day behind the japanese time. So it could be possible that this image is covering March 15th. But the shadows are not long enough and are coming from southsoutheast - I think the picture was taken around 10-12am March 15th japanese standard time...

http://www.reuters.com/article/2011/03/15/japan-nuclear-holes-idUSTFD00668920110315
 
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  • #4,335
Borek said:
Your yellow trajectories don't take into account visible tracks on the turbine building roof - it looks like whatever felt through the roof to the inside of the building was first sliding and didn't get through till it slowed down enough.
I saw the trajectories of dust on the turbine building roof but i didn't condidered, because only the weight of the masses cannot "break" the roof (as you suggest that it was "sliding" upon it). Maybe something very very hot but i don't remember (from the thermal images). Why don't you suggest graphically, as TCUP did, some trajectories?
 

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  • #4,336
the teoretizing about collateral damage from reactor 3: how reactor 3 tore reactor 4 bldg apart but not reactor 2 bldg? Which is, incidentally, at the most destroyed size of reactor 3.
 
  • #4,337
artax said:
Beginning to sound promising... actual plan with numbers in!

from the new york Times:-

"Anne Lauvergeon, the chief executive of Areva, France’s nuclear power equipment provider, said at a news conference in Tokyo on Tuesday evening that it would take at least until the end of May to set up a water treatment station at the Fukushima nuclear plant and begin purifying water. Once running, the water treatment facility should be able to handle 50 metric tons of water an hour and will be able to reduce the radiation in the water by 99.9 percent to 99.99 percent.

Ms. Lauvergeon said that even having the system up by the end of May would pose a big challenge. “It is a fight against time, but we are doing everything in our power” to meet this timeline, she said. "

some more here :
In a process called co-precipitation, the water will be treated with chemicals that cause radioactive material to settle out.
...
By contrast, a floating treatment facility built by Japan and Russia for water with low-level radioactive contamination has a capacity of only 7,000 tons a year.
http://e.nikkei.com/e/fr/tnks/Nni20110419D19JFA25.htm
 
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  • #4,338
clancy688 said:
<..>

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

This image was taken on March 14th - but I don't know the exact time zone and the exakt time. <..>

It is from 02:04 GMT, or 11:04 JST. That is 3 minutes after the steam explosion of unit 3.

In the attached zoom out you can see the plume of steam from the hot water expelled over the area, drifting out over the ocean and as a haze around unit 3 and 4, and the attached turbine buildings.

In the attached zoom in, you can see up closer the steam haze from the expelled water still hanging around unit 3, and, from the center of unit 3, get a clearer view of the distinct, less transient, and more bluish white smoke/steam fan from the leaking reactor containment.
 

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  • #4,339
rowmag said:
Following up to myself: From page number 8 (PDF page 10) of http://www.tepco.co.jp/nu/f1-np/press_f1/2008/pdfdata/bi8a08-j.pdf, they report that a suspected leaking fuel assembly in the core had been identified during operation in 2007, I gather by sliding different sets of control rods in and out with the plant running at reduced output until they managed to get the leaked radioactive gas to stop being produced. They isolated that assembly by inserting the control rods around it, and went back up to full power until the scheduled maintenance/inspection period in 2008. When they eventually pulled the suspect assembly out, it showed no visible signs of damage, but they treated it as a spent fuel assembly and did not re-use it.
This is pretty standard in the industry with respect to BWR failures. An operating failure can be found by inserting a control blade adjacent to the failure. During the process, the off-gas (Xe-133, Kr-85m, Kr-87, Kr-88, Xe-135/135m, Xe-138) activity is monitored for changes. A reduction in activity indicates a possible leaking fuel assembly.

The process has been called 'flux-tilting'. The process was codified about 18 years ago and is now generally called power suppression testing (PST). Once the failure is located the local control blade is inserted, and others maybe inserted as well in order to reduce the power in the failed assembly. Most utilities prefer to shutdown the reactor in a mid-cycle outage to remove the failed assembly.

It is policy not to return a failed assembly or one suspected as failed to the core.

Meanwhile the industry has been working to achieve zero failures in LWR fuel.
 
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  • #4,340
MadderDoc said:
It is from 02:04 GMT, or 11:04 JST. That is 3 minutes after the steam explosion of unit 3.

So the damage TCups pointed at at the turbine building facing Unit 4 was already there three minutes after Unit 3 exploded?

11:01 JST / March 14th - #3 explosion:

11:04 JST / March 14th - Sat images show extensive damage to building #3 AND two damaged spots at the turbine building facing #4.

6:00 JST / March 15th - first explosion at #4 ejects two wall panels and damages #3 further (according to TEPCO)

9:40 JST / March 15th - fire in SFP at #4So the damage TCups pointed out was already there before Unit 4 exploded... Maybe it did come from Unit 3 after all?
 
  • #4,341
I've aligned the sat and the uav pictures somewhat, additionally I drew some lines (they're not 100% exact).

http://min.us/lkC3Tm
 
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  • #4,342
Dmytry said:
it is impossible to predict anything there imo. I would of never thought they'd be using 2 robots, one with radiation monitor strapped to it, other to look at the monitor, 38 days in, versus some KHG robot.

What is a KHG robot ? I can't find it on acronymfinder.com.
 
  • #4,343
TCups said:
But the impacts on the turbine building are real. They weren't there before the explosion.

You cached something , but I do not thinks it is what you were hoping for. From the geoimage, missing the alleged blasted panel from Building 4 , is.
And where you see Impacts, I see pieces of tar from Building 3.
Keep hunting :)
[PLAIN]http://img864.imageshack.us/img864/5538/tartroof.jpg

ps: http://min.us/lkC3Tm .. I need to learn to present things in a tiny manner like this...
 
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  • #4,345
tsutsuji said:
What is a KHG robot ? I can't find it on acronymfinder.com.

Na Ja das ist aber Deutsch vür Kerntechnische Hilfsdienst GmbH
http://www.khgmbh.de/wEnglisch/intro_fernhantierung.php
 
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  • #4,346
YouTube user Anjiin it would seem, works in a Japanese nuclear plant, and years ago uploaded a lot of mundane videos from inside the reactor area.

http://www.youtube.com/user/Anjiin#p/u/10/eJeEka0qcng

I see Fukushima Prefecture listed in the descriptions.
TU-1(BWR) Tsuruga-shi.Fukui Pref. JAPAN
The removal work of FW
https://www.youtube.com/watch?v=eJeEka0qcng

Don't know the relevance, but there they are.

This one seemed quite interesting.

https://www.youtube.com/watch?v=DDE3pqEBfU8
 
  • #4,347
NUCENG said:

Thanks.

"Areva is also currently training in France Japanese technicians from Atox, a Japanese nuclear site intervention company, to the handling of specialized robots, enabling them to later enter in action in Fukushima" :

Areva forme en outre actuellement en France des techniciens japonais de la société nippone d’intervention sur sites nucléaires Atox à la manipulation de robots spécialisés, afin de leur permettre d’entrer ultérieurement en action à Fukushima.

19/04 2:57 p.m. CET

http://fr.euronews.net/depeches/872...ge-de-la-decontamination-de-leau-radioactive/
 
  • #4,348
tsutsuji said:
Thanks.

"Areva is also currently training in France Japanese technicians from Atox, a Japanese nuclear site intervention company, to the handling of specialized robots, enabling them to later enter in action in Fukushima" :
I wonder why it makes me think that they are not permitting pre-trained foreign experts to do it. It's 40 days in. They got 2 bots, one with consumer grade radiation monitor by the look of it, other to look at the readings.
For KHG, see this: http://www.khgmbh.de/wEnglisch/unternehmen_film.php?navanchor=1010039
 
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  • #4,349
another alignment of the reactors..
[URL]http://blog.bottomlessinc.com/wp-content/uploads/2011/04/fukushima_reactor_3_total_destruction.jpg[/URL]
 
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  • #4,350
Dmytry said:
I wonder why it makes me think that they are not permitting pre-trained foreign experts to do it. It's 40 days in. They got 2 bots, one with consumer grade radiation monitor by the look of it, other to look at the readings.
For KHG, see this: http://www.khgmbh.de/wEnglisch/unternehmen_film.php?navanchor=1010039

Their "EROS" robot is nice. Dose rates of 10^2 Gy/h, Max Dose Rate 10^4Gy, ability to climb stairs, that should do for some scouting.

The KHG guys must be pissed to see what's currently happening in Japan. Imagine you have all these tools at hand and then you see the someone operating two robots with a counter taped to one and a camera on the other. I'd be fuming.

I can't figure out why they haven't pinned a cam to a boom yet to check the inside of 3/4. I mean, what we've seen of it is laughable. I'm very curious to see what's in #3 and how #4 is looking on the inside.
 
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