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.
  • #13,406
turi said:
Thanks for the link. Does anyone know what the vertical orange "thing" in the unprocessed image is? The processed image doesn't have such an artifact. What kind of processing is done anyway? Adjustment for the distance of the radiation source from the camera?
attachment.php?attachmentid=47716&stc=1&d=1338209806.jpg

I don't know what the artifact is but the "unprocessed" & "processed" images are framed differently so perhaps not even the same actual image. The second pair look like they ARE the same image, pre and post processing.

http://www.tepco.co.jp/en/nu/fukushi...20525_06-e.pdf
 
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  • #13,407


MadderDoc said:
I of course agree on all points above. So there's a document which includes photos for apparent documentation which are totally unsuitable as evidence for or against cracks in the context of the inquiry, but it is perfectly alright with Tepco if the reader will conclude from looking at the photos that there are no cracks there at all. In fact that appears to be the intention of the document. I am not worried about that crack, but I don't like to be bs'ed.

On the other hand, the possible crack we have observed in the 2011 images could be easily misconstrued so tepco kept it out of frame as it's not relevant to the SFP wall as such. That the possible crack we have seen is closer to the PCV than the SFP is another thing.

Edit: Of interest perhaps is that the translation I got may not be correct but the Japanese Tepco document is talking about "local bulges". not cracks.
 
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  • #13,408


westfield said:
Perhaps I'm being too finiky but the images from 2011 don't quite show the "west wall" of the SFP as such.

The 2011 images cover the areas marked in green here.
http://i1185.photobucket.com/albums/z360/fukuwest/misc/u4sfpwalls.png

Well, whatever the terminology, the 2011 photos are of the same wall section as shown in the bottom right photo in the recent Tepco announcement:
fukushimareactor4SFPMay25-7.JPG
 
  • #13,409


MadderDoc said:
Something is necessary to explain the particular damages of the SE corner of the roof.

Did anyone suggest that the extensive damage might be due to the debris falling from the explosion, a lot of which seemed to fall on the SE corner of the RB?
Or is this a different aspect of the damage we are talking about?

Marked video clip
 
  • #13,410


westfield said:
Did anyone suggest that the extensive damage might be due to the debris falling from the explosion, a lot of which seemed to fall on the SE corner of the RB?
Or is this a different aspect of the damage we are talking about?

Marked video clip

I don't remember anyone suggesting that, but I've had the thought myself, however I left it at the wayside, as it did not appear to me to be sufficient to explain those extensive damages. It would seem weird to assume the fire phenomenon of that corner didn't leave its special marks of damage, as weird as assuming that tons of debris hitting the area from aloft seconds later didn't add to it.
 
  • #13,411


MadderDoc said:
Most video footage of the explosion which have been or remain still available have been quite unfortunately re-sampled and re-compressed from an original 50Hz interlaced TV recording, to e.g. the commonly found 29.968fps on youtube. Unavoidably such a conversion produces horrible artefacts, and comes with loss and blending of the original information.

From a short lineage recording of an original TV broadcast, it has been possible to produce this http://www.gyldengrisgaard.eu/fuku_docs/unit3cloud50fps/ . Since the original is 50 Hz interlaced, utilising both fields yields a temporal resolution of 50 fps, or 20 milliseconds per frame. You won't find this better anywhere else on internet :-)

Those of you who have taken special interest in the explosion will note particularly the extra temporal resolution at around the time of the first signs of something happening with the building.

That shows even better that little puff of white coming out of the SE corner before the orange colour of the initial explosion. nicely done.
Makes me wonder of any of that "flame" was actually inside the RB as it disassemled itself.
 
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  • #13,412
MadderDoc said:
I wonder what kind of sick paranoia has led to the blocking out of the rack number in the photo on page 5 of that document.
(It is rack number 26, if someone should want to know.)
ParanoiaScreenshot.png

The real paranoids are going to have a field day if they get a hold of this one. "The fuel rack that shouldn't have been there!"
 
  • #13,413


westfield said:
On the other hand, the possible crack we have observed in the 2011 images could be easily misconstrued so tepco kept it out of frame as it's not relevant to the SFP wall as such.
Yeah, right. And they downsampled the photo such as to not confuse people with minor details. Saltwater in my eyes.

Speaking of details, what would be the nature of the white stains running down that part of the wall below the crack above them in the photo from the 2012 announcement? There are no stains visible in the 2011 photo of the same spot:
111110_11-2012.jpg


That the possible crack we have seen is closer to the PCV than the SFP is another thing.

Well, that depends on which end of the crack we are looking at. It is about 7 m long, and the south end of it is definitely closer to the SFP than it is to the PCV.
 
  • #13,414
westfield said:
Did anyone suggest that the extensive damage might be due to the debris falling from the explosion, a lot of which seemed to fall on the SE corner of the RB?
Or is this a different aspect of the damage we are talking about?

Marked video clip


Different aspect, not impossible. Some indications:

52doat.png

11rrbj9.png


The holes in the turbine-building can't be from columns of the east-wall, because all of them are found in place or a few meters around.
 
  • #13,415
zapperzero said:
The real paranoids are going to have a field day if they get a hold of this one. "The fuel rack that shouldn't have been there!"

Grin. Here's the number tag, Tepco does not want you to see:
Paranoia2.jpg
 
  • #13,416
MadderDoc said:
I wonder what kind of sick paranoia has led to the blocking out of the rack number in the photo on page 5 of that document.
(It is rack number 26, if someone should want to know.)
ParanoiaScreenshot.png

Perhaps they're trying to avoid suggesting that that is the particular rack in question. In other words, the picture is an example, but they may pick a different rack - it seems they don't know for sure how many they are going to sample, even.
 
  • #13,417
Unit 4 SFP (was...)

biggerten said:
Perhaps they're trying to avoid suggesting that that is the particular rack in question. In other words, the picture is an example, but they may pick a different rack - it seems they don't know for sure how many they are going to sample, even.

I think they have been clear about their intention to remove 2 new fuel assemblies from a rack, and to remove them from positions where an unintentional drop during the operation has low probability of damaging close by spent fuel assemblies. It is not credible that they haven't picked their favoured target positions.

Paranoia3.jpg
 
  • #13,418


MadderDoc said:
Speaking of details, what would be the nature of the white stains running down that part of the wall below the crack above them in the photo from the 2012 announcement? There are no stains visible in the 2011 photo of the same spot:

Previous white stains or liquid on some stuff in the upper parts of reactor 4 were very likely the anti-scatter material that they sprayed all over that and some other buildings last year. But I am unsure if this is the explanation in this case, since I don't know when the 2011 photo was taken.
 
  • #13,419


SteveElbows said:
Previous white stains or liquid on some stuff in the upper parts of reactor 4 were very likely the anti-scatter material that they sprayed all over that and some other buildings last year. But I am unsure if this is the explanation in this case, since I don't know when the 2011 photo was taken.

It is from the package released on Nov 10th, in which all photos according to Tepco were taken on November 8th. However some of the photos in the package have EXIF date October 5th, and some of them appear to have been cropped/ downsampled, as is the case with this one, and the EXIF date has been lost.
 
  • #13,420
Reactor 3 TIP room investigation

SteveElbows said:
I see the reactor 3 TIP room investigation was a bit of a failure, due to door etc debris.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120524_06-e.pdf

Given that a human was able to visually inspect one part of the room, I am less than impressed about a lack of photo of this area. It makes me curious about the nature of any debris inside the room.

Now I wonder what that recent investigation was really about. Tepco would have known for more than a year, since the first robot expedition to the area, that the entrance to the TIP room was blocked, so that a robot would not be able to enter. Indeed the new video indicates that a large object close to the entrance to the TIP room has been moved, so there have been humans at the spot too since then. So why make an effort to 'rediscover' that the entrance is blocked, rather than make an effort to unblock it -- which would seem the rational thing to do, if one _really_ would like to inspect the room? And as you mention, weirdly there is apparently not even a photo of the room to show from the latest mission. Was it all just a stunt?

20110411_Unit3_TIProom.jpg
 
  • #13,421
This is a document from one month ago :

tsutsuji said:
The 5th mid long term meeting : http://www.meti.go.jp/earthquake/nuclear/20120423_02.html
...
3-1 Cooling by closed loop water injection

http://www.meti.go.jp/earthquake/nuclear/pdf/120423/120423_02g.pdf Report on the results of mock-up tests for the purpose of installing alternative RPV thermometers

( See also my translation of the 1 March 2012 report on the same topic (alternative thermometer insertion) : https://www.physicsforums.com/showpost.php?p=3795578&postcount=12465 part 1, https://www.physicsforums.com/showpost.php?p=3796935&postcount=12485 part 2, https://www.physicsforums.com/showpost.php?p=3799356&postcount=12492 part 3)

Translation:

1/12
attachment.php?attachmentid=47942&stc=1&d=1338670349.png

2/12
attachment.php?attachmentid=47943&stc=1&d=1338670347.jpg

3/12
attachment.php?attachmentid=47944&stc=1&d=1338670347.jpg
 

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  • #13,422
Translation:

4/12
attachment.php?attachmentid=47945&stc=1&d=1338670486.png

5/12
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6/12
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  • #13,423
Translation:

7/12
attachment.php?attachmentid=47948&stc=1&d=1338670633.png

8/12
attachment.php?attachmentid=47949&stc=1&d=1338670633.jpg

9/12
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  • #13,424
Translation:

10/12
attachment.php?attachmentid=47951&stc=1&d=1338670757.png

11/12
attachment.php?attachmentid=47954&stc=1&d=1338670994.png

12/12
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  • #13,425
Seaside construction work

What are those big dark structures that have been raised on the seaside of Unit 2 turbine building?
628x471.jpg
 
  • #13,426


tepcounit3tipdoor.png


Assuming the TIP room door was hinged normally at the time of the earthquake, how would it have been possible to have the door closed,
considering Tepco apparently for some reason had placed a reddish beam along the ceiling protruding out through the doorway?

unit3tipdoor.jpg
 
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  • #13,427


westfield said:
Of interest perhaps is that the translation I got may not be correct but the Japanese Tepco document is talking about "local bulges". not cracks.

MadderDoc said:
Yeah, right. And they downsampled the photo such as to not confuse people with minor details. Saltwater in my eyes.

Speaking of details, what would be the nature of the white stains running down that part of the wall below the crack above them in the photo from the 2012 announcement? There are no stains visible in the 2011 photo of the same spot:
(photo here)

Well, that depends on which end of the crack we are looking at. It is about 7 m long, and the south end of it is definitely closer to the SFP than it is to the PCV.

Looking at Tepco photo page of Nov 10, 2011
(Sorry, physicsforums does not allow me to include source links).

First observation. Floor 5 has been lifted up.
111110_03.jpg

Thus bars carrying floor 5 must have severed a little bit from pillars/walls and displaced slightly.
Proof (look upper right part, see also cracks propagating from bulging):
111110_06.jpg

This lifting up of the floor apparently created a bulging propagating from bulging seen in pic above.
111110_12.jpg

Maybe "cracking" and "bulging" are to be interpreted synonymously to some extent?
 
  • #13,428
I also don't understand this TIP room story.

First they say the door is closed, then they suddenly discover that it is blown away. How come?
 
  • #13,429
We are again in debt to Tsutsuji-san for his continuing work in keeping this forum informed about the details of TEPCO's clean up effort.
It seems that there is a very large and well analysed push under way to allow TEPCO to make some visible headway with the cleanup. Presumably the entire Japanese nuclear community is dedicating resources towards that goal, if only to avoid the nuclear exit embraced for the moment by Germany and advocated by Mr Kan.
The scale of the work visible on the site and the detail planning shown in the documents Tsutsuji-san has unearthed suggest a 'no expense spared' program. That would seem to require confidence that the situation is reasonably stable and fairly well understood.
Yet the public posture and the discussions still center on a near bankrupt TEPCO and a very limited level of outside disclosure about a situation perceived to be tenuous.
It is hard to reconcile these two perspectives.
 
  • #13,430
tsutsuji said:
The 6th mid long term meeting was held yesterday: http://www.meti.go.jp/earthquake/nuclear/20120528_02.html

28 May 2012 government-Tokyo Electric mid and long term response committee, steering committee (6th meeting)

...

3-1 Cooling by closed loop water injection

...

http://www.meti.go.jp/earthquake/nuclear/pdf/120528/120528_02h.pdf Results of the surveys on location concerning the environment improvement for the purpose of installing alternative thermometers in unit 2's RPV.

See also on the same topic (alternative thermometer insertion) : my translation of the 1 March 2012 report ( https://www.physicsforums.com/showpost.php?p=3795578&postcount=12465 part 1, https://www.physicsforums.com/showpost.php?p=3796935&postcount=12485 part 2, https://www.physicsforums.com/showpost.php?p=3799356&postcount=12492 part 3) and of the 23 April report just above ( https://www.physicsforums.com/showthread.php?p=3939578#post3939578 )

See also the videos:

http://photo.tepco.co.jp/en/date/2012/201206-e/120601_02e.html "Decontamination around the truck bay door at Unit 2, Fukushima Daiichi NPS" (released on 1 June 2012)

http://photo.tepco.co.jp/en/date/2012/201206-e/120601_01e.html "Mock-up test to check the insertability of the alternative thermometer at Unit 2" (released on 1 June 2012)

Translation:

1/10
attachment.php?attachmentid=47990&stc=1&d=1338760859.png

2/10
attachment.php?attachmentid=47991&stc=1&d=1338760859.png

3/10
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  • #13,431
Translation:

4/10
attachment.php?attachmentid=47993&stc=1&d=1338760993.jpg

5/10
attachment.php?attachmentid=47994&stc=1&d=1338760993.png

6/10
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  • #13,432
Translation:

7/10
attachment.php?attachmentid=47996&stc=1&d=1338761112.png

8/10
attachment.php?attachmentid=47997&stc=1&d=1338761112.png

9/10
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  • #13,433
Translation:

10/10
attachment.php?attachmentid=48017&stc=1&d=1338802589.png
 

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  • #13,434


MadderDoc said:
What are those big dark structures that have been raised on the seaside of Unit 2 turbine building?
628x471.jpg

Earlier this year, a similar structure existed on the seaside of the unit 1 turbine building (see below), however that construction site appears in the more recent photo above to be back levelled. This would seem to indicate these structures may be only temporary covers for some ground work.
http://gyldengrisgaard.eu/fuku_docs/r4897_39_satellite-image-fukushima-2012-xl-2_detail.jpg

Might this activity be about blocking outflow of high radiation level water through trenches, and from pipes from the backwash pits?

http://gyldengrisgaard.eu/fuku_docs/trenches_thumb.jpg
http://gyldengrisgaard.eu/fuku_docs/trenches.png
 
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  • #13,435


It is disconcerting to see in the latest helicopter footage that there has been so little apparent progress at the seaside of the plant. The building of the temporary tidal barrier seems to have come to a halt at Unit 4, and there is no indication of any progress of the steel pile barrier, the start of construction of which in the seafront of Unit 4 was announced many months ago. (If I understand the mid-term plan it is to not have a water tight barrier in place at the sea front before until some time in 2014, at the earliest).

http://gyldengrisgaard.eu/fuku_docs/daiichi-12-0528-01-hr_thumb.jpg The minimal work visible on the site as regards mitigation against emissions to the ocean and the apparent lack of detailed planning suggest a 'don't rush things' program, indicating that the measures against ocean emission are still pretty much ad hoc and the situation not yet under control. Yet the corporate posture is that emission to the ocean is something to be avoided at all costs, unless in situations of utmost necessity. It is not easy to reconcile these two perspectives.
 
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  • #13,436
I updated the tables concerning Cs activities of the water at the treatment facilities. The activities seem to have dropped by about a decade in 9 months.
 

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  • #13,437
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120605_03-e.pdf "Unit 4 Spent Fuel Pool Alternative Cooling System Secondary System Circulation Pump (A) Situation of the Burnt Area Near the Motor Terminal Housing"

http://www.tepco.co.jp/nu/fukushima-np/images/handouts_120605_04-j.pdf At 20:03 on 4 June unit 4 SFP had an "airfin cooler panel alarm" ringing, and it was found that secondary circuit pump A had tripped with some traces of burning on the pump's terminal box. Pump B was started at 20:27. At 10:30 on 5 June, pump B was shut down in order to perform an inspection. As the pool temperature is expected to rise by 0.3 °C/hour, this is not considered as being a problem for pool temperature control.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120606/index.html Unit 4 SFP temperature reached 42°C at 5 PM on 6 June. As Tepco found a malfunction in the connecting part between motor and cable [that must be the terminal box] of the backup pump [that must be pump B] as well, they made repairs and restarted the pump after 6 PM, and the pool is being cooled again. Tepco explains: "as the pool is further cooled, the temperature might drop by 10°C in half or in one day".

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120605/index.html The final version of Tepco's internal investigation report, which must be released this month, is nearly finished. [ The 2 December version was an "interim report"]. Against the cabinet investigation committee's accusation of mismanagement of the situation at units 1 and 3, it argues in defence for example that "responding was actually difficult". However the report recognizes about unit 1, that there was not enough training to cope with blackouts. About unit 3, against the cabinet investigation committee report's claim that "the risk of running out of batteries had been minimized, which led to the water injection failure", Tepco's report says "as there was a worry that the water injection equipment was damaged, it was necessary to shut it down early".
 
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  • #13,438


MadderDoc said:
It is disconcerting to see in the latest helicopter footage that there has been so little apparent progress at the seaside of the plant.

Which helicopter footage is that? Cheers.
 
  • #13,439
The white stuff may be the salt left behind by the many thousands of gallons of seawater that were sprayed willy nilly about the place.
 
  • #13,440

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