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.
  • #5,521
elektrownik said:
http://www.meti.go.jp/press/2011/05/20110501003/20110501003-3.pdf
Report number & temperature reactor 1:
119 - 107,3 C
120 - 114,7 C
121 - 131,2 C
122 - 142 C
But also other units temperature increase, but not so quick like 1.
This is strange, for example there wasnt change in pressure and water injection level but temperature changed from 114 to 131 and from 131 to 142...

Water injection has been slowed, I think. At least for unit 1.
http://www.bloomberg.com/news/2011-04-29/tepco-slows-water-injection-at-reactor-to-curb-risk-of-explosion.html
 
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  • #5,522
Heat up, fission products, etc: Maybe they ran out of boron.

Rive said:
Nope :smile: I (you) need an energy equivalent.

x Bq I131 = y J.

Re: the energy output required to make a specific amount of iodine through fission:

http://en.wikipedia.org/wiki/Iodine-131
I-131 yield in fission = 0.029 [slightly dubious 'cause it varies to neutron energy, but should be in this ballpark]
fission:
http://en.wikipedia.org/wiki/Uranium-235
energy yield: 2E8 eV per fission
energy per atom of I-131 = 2E8/0.029 = 6.9E9 eV
There has to be
t1/2/ln(2) atoms per Bq which, for i-131, is very nearly 1E6 atoms per Bq.
http://www.wolframalpha.com/input/?i=((8.0252+days)/ln(2))/second

The fission energy per Bq of I-131 is then 1.1E-3 J
http://www.wolframalpha.com/input/?i=(((8.0252+days)/ln(2))/second)*(6.9E9+eV)

100KW of fission, for 1 day, makes 7.8E12 Bq of I-131.
http://www.wolframalpha.com/input/?i=(100kw*1+day)/((((8.0252+days)/ln(2))/second)*(6.9E9+eV))

edit: note, noscript strips parens out of the url. The final formula is:
(100kw*1 day)/((((8.0252 days)/ln(2))/second)*(6.9E9 eV))

you guys do the concentrations and volumes, it's late night here. I didn't check my sources, so beware.
 
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  • #5,523
Jorge Stolfi said:
(D) These seem to be the pipes/cables that, in latter pictures, connect to the Big Grayish Closet on the south wall of the building, below the window. Does it mean that the Big Grenish Closet is not the Mickey Mouse scaffolding, but a separate Mystery?

Yes, it would appear so, and there's more.. I found a third image of reasonable resolution taken on March 12th, apparently on the same overflight as the photo you are looking at. This new photo is looking in from SW, giving a good view to the corner by that window. Here's a blow up of that part, find links to the source and the original image below.

04_42-27775632_detail_unit4.jpg


There's the big green closet, if I am not mistaken, at the window. Furthermore, look to the left of the window, at ground level as best we can see in the photo. There appears to be yet _another_ albeit smaller 'closet', standing apparently flush to the south wall of the reactor building, close to its SE corner. The original photo is at:
http://www.pbs.org/wgbh/nova/insidenova/04_42-27775632.jpg
linked from the page at:
http://www.pbs.org/wgbh/nova/insidenova/2011/03/earthquake-geology.html
 
  • #5,524
MadderDoc said:
"The image showed the status of the storage pool about six meters below the surface of the water."

Curious. In the video, we see no change in visual field, neither during the putative 6 meter submersion of the camera, nor, during its 6 meter retraction from the water. The framerate of the video is 30 frames/second, so if the complete submersion/ retraction should have occurred between one frame and the next we would be looking at a speed of the tip of the concrete pump during the submersion/retraction, of at least 6 meter/0.03 seconds = 200 m/s. That's 730 km/h, or appr. 500 mph!
:biggrin:

Well, my native language isn't english, but the way a read that sentence was something like this:
"The image showed the status of the top of the fuel rods located about six meters below the surface of the water."

So in other words they put the camera in the pool. Submersed it a bit. Took some pictures and then got the hell out of there.
And somehow they knew that that the depth where the top of the rods where was about six meters.
I hope this clears it up a little. :rolleyes:
 
  • #5,525
MiceAndMen said:
<..>maybe whatever was happening on the low roof in the SE corner of the building was in a support role for all that extra stuff.

Yes, that's also the direction my thoughts are going in after all the photo-twitching. There's an endpoint of a 66kV line on a big transformer in that corner, and a bunch of wires seems to lead from the different boxes and closets we have looking at in the direction of that transformer. The support role could be to serve a need for supply of extra electricity.

The explosions in buildings 1 and 3 have been attributed to a buildup of H2 gas that escaped from primary containments. The etiology of the building 4 explosion must have been very different. Did the green box/framework/hole apparition and/or the core shroud replacement work contribute to the explosion of building 4? I think we're no closer to answering that question than we were on 12 March.

The possibility that the 'hole' was indeed a hole was what sparked my interest in it. It would have been an indication of earthquake damage quite close to the SFP, and damage to the SFP area could have led to its leaking faster, ultimately leading to overheating, hydrogen production, and boom. But, as we have uncovered, the evidence does suggest another explanation of the whole mickey.
 
  • #5,526
Cainnech said:
:biggrin:

Well, my native language isn't english, but the way a read that sentence was something like this:
"The image showed the status of the top of the fuel rods located about six meters below the surface of the water."

So in other words they put the camera in the pool. Submersed it a bit. Took some pictures and then got the hell out of there.
And somehow they knew that that the depth where the top of the rods where was about six meters.
I hope this clears it up a little. :rolleyes:

It certainly does, and I am happy to accept your alternative interpretation, because however fine machines these concrete pumps are, they couldn't possibly move their 'trunk' at that speed, I just couldn't make that fit.
 
  • #5,527
gmax137 said:
Does anyone have any reliable info on the nuclear plants - the reports on the news seem garbled to me.

This was the very first post on this trhread, 50 days and 5500 posts ago. It still seems quite relevant... :confused:
 
  • #5,528
MadderDoc said:
Yes, it would appear so, and there's more.. I found a third image of reasonable resolution taken on March 12th, apparently on the same overflight as the photo you are looking at. This new photo is looking in from SW, giving a good view to the corner by that window. Here's a blow up of that part, find links to the source and the original image below.

04_42-27775632_detail_unit4.jpg


There's the big green closet, if I am not mistaken, at the window. Furthermore, look to the left of the window, at ground level as best we can see in the photo. There appears to be yet _another_ albeit smaller 'closet', standing apparently flush to the south wall of the reactor building, close to its SE corner.


The original photo is at:
http://www.pbs.org/wgbh/nova/insidenova/04_42-27775632.jpg
linked from the page at:
http://www.pbs.org/wgbh/nova/insidenova/2011/03/earthquake-geology.html

At the Original Foto, the Truck in Unit4 is not to see, the Door is closed.
 

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  • #5,529
Jorge Stolfi said:
This was the very first post on this thread, 50 days and 5500 posts ago. It still seems quite relevant... :confused:

Indeed, indeed. Some of the other comments from the first days are quite interesting in retrospect. It's tiresome but illuminating to read back in the thread.
 
  • #5,530
triumph61 said:
At the Original Foto, the Truck in Unit4 is not to see, the Door is closed.

Is that a person standing on the knoll in the far right of the picture?
 
  • #5,531
Jorge Stolfi said:
[PLAIN]http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/blueprint/foto/edited/out/avg-090-099-c-A-i.png

(C) Osama bin Laden, no doubt about it.

Did you already collect your 25million $ reward for reporting Osama bin Ladens location to the US...?
 
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  • #5,532
Jorge Stolfi said:
An underwater video of the #4 SFP (110428_1.zip) was recently posted on this thread.
I extracted the frames with

ffmpeg -i video.mpg -vcodec png frames-b/%08d.png

(The "-vcodec png" option and png output format apparently gives better images than the default extraction to JPEG format; the latter has a good amount of the 8x8 JPEG block noise).

Then I randomly picked 10 successive frames (90-99), aligned them manually, averaged them, and applied some brightness/contrast correction to each channel. Here is the result:
[PLAIN]http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/blueprint/foto/edited/src/avg-090-099-c.png
I am sure one can get much sharper images out of that video, with better processing tools. (Again, I don't see why one should take a low-res video from a static target, rather than a few high-res photos. Sigh.) There is much image deformation by thermal gradients in the water; the water must be boling inside some racks.

Some notes:
[PLAIN]http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/blueprint/foto/edited/out/avg-090-099-c-A-i.png

(A) These bumps on the rack edges are normal features of the racks, correct? Why do the ones in row n-2 look different from those in row 2?

(B) This streak is the result of averaging the motion of a floating object (paint flake?)

(C) Osama bin Laden, no doubt about it.

EDIT: It turns out that frames 90-99 are particularly bad. Frames 40-63 are much better. I should try again with those.

From the latest from the WH, it may not be Osama after all. ;-}
 
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  • #5,533
NUCENG said:
From the latest from the WH, it may not be Osama after all. ;-}
'B' is a jellyfish...
 
  • #5,534
8 workers to enter building of reactor N°1 Thursday...
http://www3.nhk.or.jp/daily/english/02_11.html

Tepco doesn't precise if these will be Tepco employees or "Jumpers" paid 5000 dollars a day.
 
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  • #5,535
Regarding the number 6 reactor:

The transfer of accumulated water in Unit 6 turbine building to a
temporary tank was conducted from 2:00 pm to 5:00 pm on May 1 and the
transfer was started from 10:00 am, May 2.
https://www4.tepco.co.jp/en/press/corp-com/release/11050202-e.html

Unit 6:
At this moment, we do not consider any reactor coolant leakage inside the
reactor happened.

TEPCO doesn't say here that the water is highly radioactive. Perhaps the reporter made a mistake in the NHK News and confused with the number 2 and 6 reactor wastewater radioactivity levels?
http://www3.nhk.or.jp/daily/english/01_15.html

My guess is that the water in the number 6 turbine building is groundwater infiltrating into the basement and it is low-level contaminated. They have had problems with groundwater earlier in the 5 and 6 units:
NISA said underground streams are a possible source. Before the crisis, streams beneath reactors No. 5 and 6 were pumped to divert water, a process that hasn't been conducted since the quake.
http://online.wsj.com/article/SB10001424052748703922504576273930625967622.html

The contamination may have come mainly from airborne radiation which has taken some time to be seen in groundwater. The only thing that remains a bit of mystery is the rising of radioactivity levels on the 20th of April.
 
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  • #5,536
NUCENG said:
From the latest from the WH, it may not be Osama after all. ;-}

Loch Ness Monster?
Yeti?
Crashed UFO?

It would help if we had some really grainy, fuzzy black-and-white images of the SFP to compare with historical records on the above potential candidates.
 
  • #5,537
Reactor 3 temperature jump:
-nisa 122: RPV 138C
-nisa 123: RPV 188C
 
  • #5,538
I promised myself I would refrain from ranting any more about TEPCO in this thread, but their strategy eludes me. I don't understand what they hope to accomplish on the ground floor of the reactor buildings besides finding more leaks. The problem is 30 meters up, and I would think affixing radiation monitors and cameras up on the blown out superstructure is where they should be concentrating their attention. It's almost as if they are afraid to do anything up top except for pumping water from a distance. Their plans are rooted in fantasy and designed for public relations more than addressing the problems IMO.
 
  • #5,539
MiceAndMen said:
I promised myself I would refrain from ranting any more about TEPCO in this thread, but their strategy eludes me. I don't understand what they hope to accomplish on the ground floor of the reactor buildings besides finding more leaks. The problem is 30 meters up, and I would think affixing radiation monitors and cameras up on the blown out superstructure is where they should be concentrating their attention. It's almost as if they are afraid to do anything up top except for pumping water from a distance. Their plans are rooted in fantasy and designed for public relations more than addressing the problems IMO.

The mindset is one of 'must get these reactors under control'.

It seems to be an inability to accept the failures that have occurred and the logical conclusion that the plant needs to be buried in sand and concrete.

This is what happens when you keep telling yourself and those around you one thing and accordingly put all your eggs in one basket - failure just is too terrible to accept.
 
  • #5,540
imandylite said:
The mindset is one of 'must get these reactors under control'.

It seems to be an inability to accept the failures that have occurred and the logical conclusion that the plant needs to be buried in sand and concrete.

This is what happens when you keep telling yourself and those around you one thing and accordingly put all your eggs in one basket - failure just is too terrible to accept.

I guess, but burying them is premature until they know exactly what they're dealing with, and they don't seem to be in any rush to find out.

Unit 1: Assign a robot to the collapsed roof to move about and take radiation measurements. If the robot fails due to radiation, put another one up there. How are they getting water into the #1 SFP right now? Is the closed-loop cooling circulation system working?

Unit 2: There is a gaping hole in the western face of the building. The roof is intact. Get a crane and deploy a robot in there ASAP.

Units 3 & 4: Get someone or something to emplace radiation monitors on the exposed steel beams of the upper superstructure. When it's safe enough to work, get some guys up there with torches to start cutting the debris away. Find 200 ironworkers and let each of them cut one beam. If it takes an hour to cut a beam and the safe exposure is 30 minutes, then find 400 workers. Find 2,000 for crying out loud, and get them up there.
 
  • #5,541
OMFG: BREAKING NEWS: Radiation leaks from fuel rods suspected at Tsuruga plant: local gov't:
 
  • #5,542
elektrownik said:
Reactor 3 temperature jump:
-nisa 122: RPV 138C
-nisa 123: RPV 188C

SFP unit 1 FPC skimmer level
-nisa 115: 4550
-nisa 123: 1650

Does this mean the pool is running dry in unit 1? Who knows? Maybe all the data in these reports do not say anything?
 
  • #5,543
  • #5,544
A very good report from the Associated Press...

http://www.blueridgenow.com/article/20110502/API/1105020602

After reading it, I feel much more confident that TEPCO and the Japanese nuclear industry are capable of dealing with the situation at the Fukushima Daiichi NPP.

[Note: sarcasm is not always readily apparent on the internet. This article has all the earmarks of a "wrap-up" story, which means the daily media coverage of the situation has come to an end barring some dramatic development that will boost ratings.
 
  • #5,545
Samy24 said:
SFP unit 1 FPC skimmer level
-nisa 115: 4550
-nisa 123: 1650

Does this mean the pool is running dry in unit 1? Who knows? Maybe all the data in these reports do not say anything?

There is a contradiction between these datas and no report about spraying in SPF1.

From the various report, the SPF level is reported to go from 4550 (Apr 26 5:00) down to 1900 (May 01 11:00).

AFAIK surface of SPF1 is around 86 meters^2 (same height as SPF2 to 5, but less volume => data taken from http://allthingsnuclear.org/post/4008511524/more-on-spent-fuel-pools-at-fukushima" ).

This is 2.65 meters of water having left the pool, this is about 229 tons, in exactly 126 hours. Which gives an average of 1.8 tons per hour.

Again somewhere in http://allthingsnuclear.org/tagged/Japan+nuclear/page/2" , boiling in SPF1 would come from a 60 Mcal/hour power, which gives a rate of 0.11 tons per hour.

Conclusion: the drop cannot be explained by boiling. Moreover, this SPF was "quiet" before Apr 26 (no change in level, no report of water spread in SFP - does not mean there had been none).

There may be accelerated leak (from Apr 26 - BIG leak), or additional heat. Edit: no report of white smoke above unit 1.

Worth noticing is the rate the concrete pump can put water in. In SPF4, they have sprayed 960 tons in 1717 minutes since Apr 19, which gives a rate of about half a ton per minute, or about 30 tons per hour.

Putting everything together, we have:
- of course they are aware of SPF1 level drop
- they are injecting water as fast as they can (?) Since no report on spraying at SFP1 ... They may be able to do at 30 tons per hour, and however pool level drops.
- SPF1 pool level may soon come to top of fuel rods. If all maths and data are correct, we can predict it will be the case at 5AM on May 5th. Edit : except if "BIG leak hole" is above top of fuel rods.
- however no PR about this, nothing in reports ?

EDIT: PFC skimmer level may not give level in SFP itself (to be continued)
 
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  • #5,546
clancy688 said:
Did you already collect your 25million $ reward for reporting Osama bin Ladens location to the US...?

I am checking whether the reward terms specify "before the US finds him". Meanwhile, consider this:
(1) News reports say that the body was dumped into seawater somewhere. Nowhere it said it was not borated seawater.
(2) I read on twitter that his hideout had walls 4m thick. Check the SFP walls on the blueprints.
:smile:
 
  • #5,547
elektrownik said:
Reactor 3 temperature jump:
-nisa 122: RPV 138C
-nisa 123: RPV 188C
Hmm. Is there any official denial out yet?

jpquantin: skimmer would not get re-filled if the pool is below the skim level, right? The skimmer is an overflow tank of some sort.
 
  • #5,548
Dmytry said:
Hmm. Is there any official denial out yet?

jpquantin: skimmer would not get re-filled if the pool is below the skim level, right? The skimmer is an overflow tank of some sort.

Well agree with you (found skimmer illustrated in http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110418e5.pdf" from Tepco). Do you mean skimmer level does not give SFP level ?
 
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  • #5,549
Dmytry said:
Hmm. Is there any official denial out yet?

jpquantin: skimmer would not get re-filled if the pool is below the skim level, right? The skimmer is an overflow tank of some sort.

Where is the water in the skimmer surge tank going? Why are they releasing this water? Does not matter, but just curious.
 
  • #5,550
Astronuc said:
Alternatively, it may be better for someone to initiate a new thread concerning "unresolved questions about the Fukushima event", and that thread can be stickied in the forum. We could divide the thread into groups of 30 or so pages (1-30, 31-60, . . ) or groups of 25, and ask folks to browse the pages for unresolved questions. We could then link back to the thread/posts. Alternatively, it may be better for those asking questions to determine if their particularly question remains unresolved.

Sorry to be running so far behind -- PF seems to be having server problems that coincide with my reading time.

What would be most helpful is a sticky that has, without additional interpretation, and indexed as appropriate (including location, date and time), links and graphics (with original source and copyright data) of:

1) technical drawings and diagrams of the physical plan at Fukushima

2) photos and videos of Fukushima

3) relevant tables, graphs & charts (ie, of radiation measurements, RPV and SFP parameters, etc.)

4) links to related articles

Going forward, perhaps posters could include such appropriate links and attachments, not only in their posts, but also appended to the appropriate sticky.

This thread is an amazing source. It deserves to be indexed and footnoted and perhaps, technically edited to better organize and categorize the content. I predict it will be a long-lasting source for technical and historical research.
 

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