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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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Ms Music
#5923
May5-11, 04:03 PM
P: 174
Quote Quote by unlurk View Post
I'm now going to search for seismic data from the times of the explosions.

I may have missed it but I don't think it has been presented here yet.

Japan is loaded with seismic sensors, it should be possible to compare amounts of energy released in the blasts in different units.
I did search at least a month ago, and was unable to find anything above 4.0. I was unable to find a website that shows earthquake data smaller than 4.0 that was in English.

Best of luck!
MadderDoc
#5924
May5-11, 04:14 PM
MadderDoc's Avatar
P: 698
I am posting a few frames from a Daiichi video that was linked here recently. They show a pressure vessel cap during mounting, and the lifting in place of the containment cap.

I think these photos indicate what that big tetrapod thing is that rests on the top of unit 3 to the north of the crane. The tetrapod would seem to be a tool affixed to the crane when it is lifting the containment cap (and perhaps when it is lifting the pressure vessel cap too, the cap appears to have on top 4 handles that would fit).
Attached Thumbnails
cap_crane_tool.jpg  
triumph61
#5925
May5-11, 04:19 PM
P: 68
I compare the radiation map (tepco) with the yellow things witch are around unit 3.
The Radiation is at the same Place high where yellow pices are found.
the highest place 330 is the smal building.
unlurk
#5926
May5-11, 04:28 PM
P: 72
Quote Quote by MadderDoc View Post
I assume you restrict to those two options because you've seen a big cloud rising vertically
Correct, and the column of "steam" reached a height of 500 meters or so very quickly in a strong SE breeze.

I have seen a lot of steam releases in my time, but never one with that much energy.
TCups
#5927
May5-11, 04:55 PM
TCups's Avatar
P: 494
Quote Quote by unlurk View Post
Correct, and the column of "steam" reached a height of 500 meters or so very quickly in a strong SE breeze.

I have seen a lot of steam releases in my time, but never one with that much energy.
Ever seen a volcano erupt?
unlurk
#5928
May5-11, 05:25 PM
P: 72
Quote Quote by TCups View Post
Ever seen a volcano erupt?
Possibly I'm being misunderstood.

I am not saying there was a nuclear explosion in the sfp.

On the basis of all the known information, I believe there was a criticality which occurred in the fuel pond.

The heat generated by the criticality created the steam explosion visible in the videos of the explosion of number 3.

The (sideways) hydrogen explosion was a powerful blast, but it was a mere puff when compared to the steam explosion which followed.

Please note that the vertical column of "steam" seen in the #3 blast was brown because it contained debris from the hydrogen blast and contents of the sfp.

This theory also appears to be supported by the presence of very "hot" radioactive debris around the site and the detection of neutron activity outside the site boundary.

Units 3 and 4 are the only suspects as the source of all the radiation around the site as far as I know.

And #4 may not have contributed much to the foul environment around the plant.
Jorge Stolfi
#5929
May5-11, 05:42 PM
P: 279
Quote Quote by unlurk View Post
the column of "steam" reached a height of 500 meters or so very quickly in a strong SE breeze. I have seen a lot of steam releases in my time, but never one with that much energy.
Could that much steam be generated from H2 + O2 ? The interior space of floors 3-4-5 is somewhat less than 30,000 m^3. Wikipedia says that explosion can happen with H2 concentration from 4% to 74%. If we take 40% (max that will burn anyway), that would be at most 12,000 m^3 of H2, which after the explosion would would become 12,000 m^3 of hot steam, which at atmospheric pressure would expand adiabatically to ... huh ... (end of my physics).

Anyway, 12,000 m^3 of H2 at 1 bar ~ 1000 kg of H2 <--> 9000 kg of H2O So the maximum H2 explosion assumed above would generate a mushroom comparable to that of the explosion of a boiler with 9 m^3 of liquid water, overheated to some temperature TBD. Is that compatible with your experience?

However for this maximum scenario we need 9 tons of water combining with zirconium (in the core, in the SFP, or both) to produce that 1 ton of H2. Is this reasonable?

If we take the lower figures, we get perhaps 20,000 m^3 of space filled with 4% H2. That means less than 70 kg of H2 <--> 630 liters of liquid water. That seems more reasonable as far as H2 generation goes; but would it yield enough steam for the mushroom we saw?

If we cannot match the amount of H2 likely to have been produced with the size of the mushroom cloud, two other possibilities are an explosive rupture of the RPV (several tons of superheated water there), or a criticality in the SFP (vaporizing some of the water).
TCups
#5930
May5-11, 05:47 PM
TCups's Avatar
P: 494
Quote Quote by unlurk View Post
Possibly I'm being misunderstood.

I am not saying there was a nuclear explosion in the sfp.

On the basis of all the known information, I believe there was a criticality which occurred in the fuel pond.

The heat generated by the criticality created the steam explosion visible in the videos of the explosion of number 3.

The (sideways) hydrogen explosion was a powerful blast, but it was a mere puff when compared to the steam explosion which followed.

Please note that the vertical column of "steam" seen in the #3 blast was brown because it contained debris from the hydrogen blast and contents of the sfp.

This theory also appears to be supported by the presence of very "hot" radioactive debris around the site and the detection of neutron activity outside the site boundary.

Units 3 and 4 are the only suspects as the source of all the radiation around the site as far as I know.

And #4 may not have contributed much to the foul environment around the plant.
@Unlurk:
Understand. Ultimately, it can be debated as to the precise source of heat that drove the steam explosion -- sudden criticality or otherwise, but not that a steam explosion occurred, IMO. The fundamental difference between the explosion at Unit 3 and the others was the component of the steam explosion, whatever its exact precipitating cause.

Basically, the water in the SFP would have been heated to the boiling point without a sudden criticality. And a hydrogen explosion would have added additional heat and, perhaps more importantly, sudden agitation of the heated water. It is plausible that a steam explosion may have occurred without or with sudden criticality. Based on the evidence and opinions of others here on the PF (Astronuc principal among them) I don't think sudden criticality occurred in SFP3.

BTW, I was pleased to see yet another new member also become a contributor to the PF. I did so, too, and believe the value received was well worth the contribution. Others are also encouraged to consider becoming contributing members. Thanks.
robinson
#5931
May5-11, 06:06 PM
P: 201
The explosion of Building 3 is fascinating. I would bet if there was video of the Building 4 explosion, it would be far more interesting as well.
jlduh
#5932
May5-11, 06:20 PM
P: 468
As general information about currently discussed safety policies evolutions in case of nuke accidents, i post this translation of a french article from 5th of May. Today have been hold auditions at the french parliament to discuss how to adress in the future, and after Fukushima, "unthinkable scenarios of accidents". "Thinking the unthinkable" is the main goal of a kind of task force that has been put in place after Fukushima where a succession of events ended up in a scenario that was never foreseen by plant designers nor self defense forces who had to cope with the desaster. They ARE NOW CLEARLY RECOGNIZING THAT CRISIS AND RISKS SCENARIOS ARE OFTEN TOO SIMPLISTIC AND DO NOT INCLUDE POSSIBLE DOMINOS EFFECTS (I mentioned this recently concerning the NRC SFP risk reassessment study, which never adressed the possibility that the reactor below the SFP could explode or trigger an explosion devastating the pools placed on the "attic"!).

Note they are also seriously considering the need to develop ressources able within 48 hours to be sent on site (with helicopters) with all the means necessary to provide an effective mobile backup of power AND water to deal with a total blackout situation in a NPP for all the reactors (loss of cold source and loss of power, from primary AND from onsite backup).

http://translate.google.fr/translate...aginable,23027
robinson
#5933
May5-11, 06:39 PM
P: 201
With out a back up cooling system nothing seems to be able to prevent a meltdown when something damages the heat exchange. Be it cooling towers, or intake/outflow from a river/ocean, if the cooling system fails, for what ever reason, there will be big trouble.

How to fix that?
mscharisma
#5934
May5-11, 06:48 PM
P: 82
Quote Quote by AntonL View Post
This livecam is some 13 km away from fukushima, very strong telephoto lens is used and these do tend to show barrel or pin-cushion distortion. You have just re-discovered the pin-cushion phenomena. Once you factor away the distortion of the lens then you can make a judgement on the verticality of the building,
Even in the live web cam, the left side towers are perfectly straight, whereas the building towards the right are leaning to the right. Hope this doesn't win the "dumbest question of the day" prize, but wouldn't the distortion go from the center (not distorted) of the picture towards both sides equally?
AntonL
#5935
May5-11, 07:00 PM
P: 521
Quote Quote by mscharisma View Post
Even in the live web cam, the left side towers are perfectly straight, whereas the building towards the right are leaning to the right. Hope this doesn't win the "dumbest question of the day" prize, but wouldn't the distortion go from the center (not distorted) of the picture towards both sides equally?
correct, unless electronic zoom or electronic selection of a part of the complete frame is transmitted

EDIT: correction, I took another frame of the TBS/JNN feed and drew some lines
looks OK to me
Dmytry
#5936
May5-11, 07:46 PM
P: 505
Quote Quote by jlduh View Post
As general information about currently discussed safety policies evolutions in case of nuke accidents, i post this translation of a french article from 5th of May. Today have been hold auditions at the french parliament to discuss how to adress in the future, and after Fukushima, "unthinkable scenarios of accidents". "Thinking the unthinkable" is the main goal of a kind of task force that has been put in place after Fukushima where a succession of events ended up in a scenario that was never foreseen by plant designers nor self defense forces who had to cope with the desaster. They ARE NOW CLEARLY RECOGNIZING THAT CRISIS AND RISKS SCENARIOS ARE OFTEN TOO SIMPLISTIC AND DO NOT INCLUDE POSSIBLE DOMINOS EFFECTS (I mentioned this recently concerning the NRC SFP risk reassessment study, which never adressed the possibility that the reactor below the SFP could explode or trigger an explosion devastating the pools placed on the "attic"!).

Note they are also seriously considering the need to develop ressources able within 48 hours to be sent on site (with helicopters) with all the means necessary to provide an effective mobile backup of power AND water to deal with a total blackout situation in a NPP for all the reactors (loss of cold source and loss of power, from primary AND from onsite backup).

http://translate.google.fr/translate...aginable,23027
Great to see sane approach. Just what I wanted to see. Complete with helicopter delivery. I wonder if they will also add helipads to the roofs (those that can withstand weight) . Thinking the unthinkable approach should include backup landing zones, as in the event of flooding there may be a problem, and it needs to be known in advance which roofs can and can't be landed onto, and where. Such things IMO are a proxy whenever there's any new thinking or it is same old doing just the absolute bare minimum.
yakiniku
#5937
May5-11, 07:50 PM
P: 30
Long time lurker here. I enjoy the open discourse. I haven't really had anything to contribute until now. My partner who is Japanese brought this blog post to my attention. It is from Taro Kono, who is in the house of representatives (LDP, opposition to current government):

http://www.taro.org/2011/05/post-996.php

In particular this section:

"エネ庁の若手官僚から添付ファイルが3通ついたメールが来た。

その一
5月1日の政府・東電統合本部全体会合の議事録。
『このままいくと8日にも高濃度の放出が行われる。』
『細野補佐官から,本件は熱交換機の設置といった次のステップに進む上で非常に重要である,また,(今後,放射性物質が外に排出され得るという点で,) 汚染水排出の際の失敗を繰り返さないよう,関係者は情報共有を密に行い,高い感度を持って取り組んで欲しい,とする発言があった。』"

Translation (non-literal and our understanding):

I received 3 emails with attachments from junior government officials in the energy department.

The first email:
Minutes of meeting between TEPCO and the government on the 1st May.
"If the current situation continues, high density radiation will be released on the 8th May."
"Mr Hosono said: It is very important to go to the next step regarding the installation of the heat exchanger machine. For the concerned parties, be careful of the sharing of information with high sensitivity so that the same mistakes aren't made again like the release of the radiated water previously.


The second and third emails aren't related so we didn't translate it. It isn't clear from the text the way the radiation will be released. ie airborne or via water.

The aforementioned energy department English homepage is this:
http://www.enecho.meti.go.jp/english/index.htm

Perhaps those who are following the work and/or parameters of the reactors could hypothesise what they are thinking about doing.
etudiant
#5938
May5-11, 08:57 PM
PF Gold
P: 858
Quote Quote by yakiniku View Post
Long time lurker here. I enjoy the open discourse. I haven't really had anything to contribute until now. My partner who is Japanese brought this blog post to my attention. It is from Taro Kono, who is in the house of representatives (LDP, opposition to current government):

http://www.taro.org/2011/05/post-996.php

In particular this section:

"エネ庁の若手官僚から添付ファイルが3通ついたメールが来た。

その一
5月1日の政府・東電統合本部全体会合の議事録。
『このままいくと8日にも高濃度の放出が行われる。』
『細野補佐官から,本件は熱交換機の設置といった次のステップに進む上で非常に重要である,また,(今後,放射性物質が外に排出され得るという点で,) 汚染水排出の際の失敗を繰り返さないよう,関係者は情報共有を密に行い,高い感度を持って取り組んで欲しい,とする発言があった。』"

Translation (non-literal and our understanding):

I received 3 emails with attachments from junior government officials in the energy department.

The first email:
Minutes of meeting between TEPCO and the government on the 1st May.
"If the current situation continues, high density radiation will be released on the 8th May."
"Mr Hosono said: It is very important to go to the next step regarding the installation of the heat exchanger machine. For the concerned parties, be careful of the sharing of information with high sensitivity so that the same mistakes aren't made again like the release of the radiated water previously.


The second and third emails aren't related so we didn't translate it. It isn't clear from the text the way the radiation will be released. ie airborne or via water.

The aforementioned energy department English homepage is this:
http://www.enecho.meti.go.jp/english/index.htm

Perhaps those who are following the work and/or parameters of the reactors could hypothesise what they are thinking about doing.
Perhaps this is related to the temperature rise discussed earlier in reactor 3.
TEPCO on Wednesday has increased the flow of water to that reactor to 9 tons/hr from 7 tons/hr.
Clearly the situation remains far from stable.
With the water in the plant and the reactor temperatures both rising, maybe there should be a reappraisal of the strategy.
razzz
#5939
May5-11, 09:02 PM
P: 205
Only Unit 1 is capable of holding any pressure. Unit 2 & 3 are at ambient air. How they expect to do a closed loop heat exchange recirculating contaminated water in Unit 1 is beyond me. Sounds desperate. Maybe they will figure that out if they can get close enough to look at the plumbing.

If the readings are to be believed, guys here keeping track of the pressures should be able to predict a likely overpressure suspect.

Unit 3 had a well formed mushroom cloud which takes a lot of heat to accomplish, while both events are happening i.e. hydrogen explosion with water flashing to steam, something else is also going on. Units 1 & 4 frameworks performed as intended with typical pent up hydrogen explosions. Unit 1 was venting radioactive wastes amongst the hydrogen release emanating from core as was Unit 3's venting.

Rust looking areas on steel was aided with saltwater dumping and pumping and part of the roofing material is likely galvanized corrugated steel plates and not aluminum.
jim hardy
#5940
May5-11, 09:09 PM
Sci Advisor
PF Gold
jim hardy's Avatar
P: 3,515
Triumph

i was sloppy in my wording a few pages back regarding yellow object in video.

I said "right next to", i should have said "adjacent to left " and if that's where you looked you have the right object. It's the video recorded from inside a vehicle, they drive up by the reactor building and stop to film a red fire truck spraying water. i lost the link, sorry... but sounds like you found it.

old jim


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