Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Borek]

The things you learn from the Japanese. I didn't even know steam could be produced by water at a temperature of 50 degrees Celsius. I also thought steam was invisible.

Water evaporates - producing steam - always, even at room tmeperatures. Leave a glass of water for long enough and it dries out - that's evaporation, no boiling needed.

Steam is invisible, but depending on conditions it can quite easily condense into fog. What people call "steam" is in fact fog. I guess (English being my second language) these things can be also classified as "dry steam" and "wet steam" - the latter containing small, visible water droplets.

 

[Bioengineer01]

Water evaporates - producing steam - always, even at room tmeperatures. Leave a glass of water for long enough and it dries out - that's evaporation, no boiling needed.

Steam is invisible, but depending on conditions it can quite easily condense into fog. What people call "steam" is in fact fog. I guess (English being my second language) these things can be also classified as "dry steam" and "wet steam" - the latter containing small, visible water droplets.

The explanation is a lot simpler, just put a very long and narrow cylindrical container full of water and apply heat to its bottom, after a while you will see water bubbles coming to the surface if the heat at the bottom is enough to vaporize and energize the layer of water at that spot so that it can reach the surface without cooling down below the boiling point. Obviously, the temperature of the surface water (opposite side to where the heat is applied) will be inversely proportional to the height of the cylinder that you used. This case can provide you with a sufficiently long cylinder and sufficient energy applied to the bottom in the form of heat, boiling water bubbles going through water at 50 C in the surface.

 

[robinson]

I guess if you define steam as water vapor, and define fog or water droplets (what we see) as steam, then it all makes sense.

 

[Bioengineer01]

I guess if you define steam as water vapor, and define fog or water droplets (what we see) as steam, then it all makes sense.

Guys, this is not vapor from normal evaporation of water, this is steam coming through the surface of water and distorting the surface in the form of bubbles, you can see the dynamics of the steam bubbles breaking the surface of the water in the video, this has a lot more energy than regular evaporation vapor. Something -The Corium?- has energized these water molecules a lot...

 

[tsutsuji]

http://www3.nhk.or.jp/daily/english/04_16.html


The steam generated in the reactor must go somewhere, that it is from 50^oC water in the basement is possibly the simpler and non alarmist message

Is this steam contaminated ? If it is, don't we need a cooling system to cool this basement to a temperature lower than 50°C in order to prevent contaminated steam from rising into the atmosphere ?

 

[agapemom]

I have been trying to read what I can of this 500+ page thread to understand what is happening at the Fukushima power plant. Most of the discussions are over my head, but I can follow the gist of the important points.

Would anyone be willing to take a stab at describing (in layman's terms): 1) the current state of the containment efforts, 2) theorizing a likely outcome, and 3) what are the likely effects of a "worst case scenario"?

In a worst case scenario, does this have the potential to create felt global health consequences, or like Chernobyl, only local or regional?

Someone asked my opinion on a FB post in this way, "break it down for us dumb dumbs and give us the cliff notes...do we head for the lead-lined hills or what?"

I guess that's what I'm trying to ask as well. :-)

 

[robinson]

Forget that steam, what about the huge clouds of steam coming out the building almost all the time? What is in that?

 

[turi]

Guys, this is not vapor from normal evaporation of water, this is steam coming through the surface of water and distorting the surface in the form of bubbles, you can see the dynamics of the steam bubbles breaking the surface of the water in the video, this has a lot more energy than regular evaporation vapor. Something -The Corium?- has energized these water molecules a lot...

I'm not convinced those are bubbles. If you look at the right side of the picture during the "bubbling" you see similar artifacts there. Because it's less dark than where that pipe is, it's less visible.

 

[hbjon]

this may be off topic but I found it as interesting nontheless :

Interesting video of a former reactor worker who seems to think he was severely wronged by GE. Hard to believe that he worked in sweatshop conditions under GE, but it makes one wonder if the slaves don't want to row anymore that they would try to sabatage a nuke plant in the event of an emergency. Is it human nature? In the event of possible destruction to the thing that is causing them harm, that they would not do everything in their power to save the thing. To me it seems unthinkable. But I always try to imagine the unthinkable so I don't get caught up in the idea of preconception. Best wishes to all. Prayers for the workers.

 

[robinson]

In a worst case scenario, does this have the potential to create felt global health consequences, or like Chernobyl, only local or regional?

I can answer that. Worst case scenario would be all the fuel burns and explodes (steam and/or hydrogen explosions, not nuclear) and ends up all over Japan, and the rest of the planet. Depending on the wind and rain it would contaminate vast areas of the planet, and could turn most of Japan into a radioactive wasteland for longer than human history.

The effects on ocean life are an unknown, but worst case scenario is so horrific nobody even wants to think about it, much less describe it in detail.

 

[robinson]

2) theorizing a likely outcome

What sane rational people would like is for all six reactors to be brought to cooldown with no more release of radiation. And all the spent fuel to be cooled and kept under water, until it can be removed and stored safely. And all the contaminated water to be cleaned up.

Then in maybe 15 or 20 years the melted fuel to be removed and safely contained. The problem is, after 25 years they still haven't been able to do this to one reactor in Russia.

 

[elektrownik]

Did last strong earthquake close to Fukushima (5,6) in last days damaged unit 1 SFP ? For some reason, water level is now only 1m, but it was 2,5-4m usal

 

[robinson]

720,000 terabecquerels of radioactive substances

http://www3.nhk.or.jp/daily/english/03_31.html

1 Ci = 37,000,000,000 Bq

Fukushima (in the water there)

720,000,000,000,000,000 Bq

Unless I made a math error, that's
19,459,459 Curies currently in just the waste water there. That doesn't include the material spread out over the land, around the world, or into the ocean from leaking water.

What was the figure for Chernobyl again?

(edit)

Ah, found it.

Chernybyl released about 1,300,000 Ci of Ce-137 and 2,400,000 Ci of Ce-137

 

[elektrownik]

Can anyone explain unit 1 sfp water level ?
Data from 5/16 to 6/4 measured 2 times per day...

 

[Astronuc]

The things you learn from the Japanese. I didn't even know steam could be produced by water at a temperature of 50 degrees Celsius. I also thought steam was invisible.

Superheated (dry) steam is more or less invisible - like air or many gases. Steam in air is usually saturated. One can see steam or saturated vapor in one's shower or from any hot water faucet, at temperatures of about 50C

 

[Jorge Stolfi]

I didn't even know steam could be produced by water at a temperature of 50 degrees Celsius. I also thought steam was invisible.

My guess: what is leaking through the gap around the pipe is air (or some other gas) at minimum 50 degrees, saturated with water vapor. As it meets the cooler air and pipe in the ground storey, some of the steam condenses into fog, some into the pool of liquid water around the pipe. The bubbles are not boiling but the warm gas bubbling through this puddle.

Er, could they put a gas chromatograph on those robots, please? Us gawkers want to know what that gas is...

 

[Jorge Stolfi]

To complement my guess: if the basement is half-flooded with water at 50 C, but at near atmospheric pressure, then the space above the water should be filled with saturated air-steam mixture at 50 C.

One puzzling detail is what is pushing that wet air through the crevice and through the water, since the pressures on both sides should equalize through the stairwell. It would require a closed door somewhere between that part of the ground floor and that part of the basement. I suppose that is not entirely unlikely?

EDIT: Instead of a door, the air pressure difference could be explained also by a low passageway in the basement that is open but entirely submerged.

 

[jim hardy]

are you guys able to make out the numbers on those new gages?
http://www.tepco.co.jp/en/news/11031.../110604_10.jpg

also the youtube linked three pages ago is now "removed by user

Originally Posted by Lambert View Post

this may be off topic but I found it as interesting nontheless :

Fascinating.

musta been good?

also - water vapor is just another gas and when above its boiling point is not too un-ideal.
What we call steam is the white stuff that's actually tiny liquid droplets that've condensed into water.
you see them on wingtips of fighter planes doing high-g maneuvers in summer airshows - air above wing cools below dewpoint and the water vapor becomes visible.
http://gwatt.smugmug.com/Airplanes/MacDill-AFB-Open-House-2008/F-18-Making-VaporDSC3336/468150589_8K57R-X2.jpg


so the steam we see in that video is real humid air entering a cooler room. Must be awfully muggy below decks.

 

[Bandit127]

http://www3.nhk.or.jp/daily/english/03_31.html

1 Ci = 37,000,000,000 Bq

Fukushima (in the water there)

720,000,000,000,000,000 Bq

Unless I made a math error, that's
19,459,459 Curies currently in just the waste water there. That doesn't include the material spread out over the land, around the world, or into the ocean from leaking water.

What was the figure for Chernobyl again?

(edit)

Ah, found it.

Chernybyl released about 1,300,000 Ci of Ce-137 and 2,400,000 Ci of Ce-137

I think a crucial difference here is that those large amounts of Curies are still contained (for the moment at least). Not as contained as we would like - but not spread out over the land either.

I don't know what the experts think, but I see the large amounts of water being used has got a benefit - and that is to reduce the amount of radiation that is being released to the environment in the way that it was in Chernobyl.

 

[MadderDoc]

are you guys able to make out the numbers on those new gages?
http://www.tepco.co.jp/en/news/110311/images/110604_10.jpg<..>

I think so;
Left instrument scale 0 - 0.5 (current reading 0.1)
Right Instrument scale 0 - 0.4 (current reading 0.2)
Center instrument scale 0 - 0.1 (current reading 0.1)
All scales in MPa

 

[robinson]

I think a crucial difference here is that those large amounts of Curies are still contained (for the moment at least).

So you checked my math? Wow, that is a lot of radioactivity. And that is just in the basements and such. Makes one wonder what the real amounts are spread all over the island and in the ocean.

It would nice to know the elements causing it as well. I don't doubt somebody already knows, but isn't going to say.

 

[Lambert]

are you guys able to make out the numbers on those new gages?
http://www.tepco.co.jp/en/news/11031.../110604_10.jpg

also the youtube linked three pages ago is now "removed by user


musta been good?

Yeah it was a interview of Kei Sugaoka, here is the info from the youtube video before it was nuked:

"Uploaded by laborvideo on Jun 3, 2011

GE Nuclear Inspector And Whistleblower Kei Sugaoka Speaks Out About Fukushima , GE & Obama
General Electric nuclear plant inspector Kei Sugaoka was one of the inspectors at the Fukushima Daiichi plant in 2000. He noticed a crack in the steam dryer which he videotaped. He was later ordered by TEPCO to edit this part of the tape which is illegal in the United States. He went public and some TEPCO managers were fired. He thought that things would change but they have not. Additionally as a result of being a whistleblower he was also fired by General Electric and has been struggling to get the truth out about these dangerous plants. This interview was done on May 5, 2011.
http://www.youtube.com/watch?v=fBjiLaVOsI4&feature=
http://criticality.org/2011/05/whistleblower-shutdown-17-nuclear-reactors/
http://www.nytimes.com/2011/04/27/world/asia/27collusion.html?hpw
http://www.baycitizen.org/disasters/story/inside-japans-failing-nuclear-react ...
http://search.japantimes.co.jp/cgi-bin/fl20040523x2.html
Production of Labor Video Project www.laborvideo.org laborvideo.blip.tv
(c)2011"


most of the links are dead now, kind of crazy... here is another link i found which is also interesting:

http://www.youtube.com/view_play_list?p=0AA0A2E17C94FC6C

 

[elektrownik]

I done this a long time ago

I think so;
Left instrument scale 0 - 0.5 (current reading 0.1)
Right Instrument scale 0 - 0.4 (current reading 0.2)
Center instrument scale 0 - 0.1 (current reading 0.1)
All scales in MPa

http://www.tepco.co.jp/en/news/110311/images/110604_10.jpg

I see now, Hight side pressure - 0,1 MPa, low side pressure 0,2 MPa, and differential pressure - 0,1 MPa
So reactor presure is 0,2 MPa - 0,18 MPA = 0,02 MPa
equation from here: http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110602_02-e.pdf
So we should now add 0,1013 to result
so 0,1013 + 0,02 = 0,1213 so it is litle bigger than atmospheric pressure ?

weee my computations were correct, look on tepco data summary 6/4 at 12:00
http://www.tepco.co.jp/nu/fukushima-np/f1/images/11060412_table_summary-j.pdf
0,025MPa + 0,1013=0,1263
So where all nitrogen go ?



Ps. also water level in unit 1 sfp hit low record - only 1m, if they will not inject water fuel will be exposed in less than 24 h

REACTOR 1 RPV IS AT ATMOSPHERIC PRESSURE !

 

[Bioengineer01]

To complement my guess: if the basement is half-flooded with water at 50 C, but at near atmospheric pressure, then the space above the water should be filled with saturated air-steam mixture at 50 C.

One puzzling detail is what is pushing that wet air through the crevice and through the water, since the pressures on both sides should equalize through the stairwell. It would require a closed door somewhere between that part of the ground floor and that part of the basement. I suppose that is not entirely unlikely?

EDIT: Instead of a door, the air pressure difference could be explained also by a low passageway in the basement that is open but entirely submerged.

What do you mean by basement when you refer to Unit 1? There is no basement below the PCV, just a concrete basemat? correct?
https://www.physicsforums.com/attachment.php?attachmentid=36166&stc=1&d=1307221110

 

[elektrownik]

What do you mean by basement when you refer to Unit 1? There is no basement below the PCV, just a concrete basemat? correct?
https://www.physicsforums.com/attachment.php?attachmentid=36166&stc=1&d=1307221110

No, not correct, floor -2 (torus) and -1, look on the tepco flood drawings, they show clear those floors

 

[LabratSR]

Could Hydrazine have anything to do the steam/water vapor/smoke/whatever seen in the video? Like lowering the boiling point or some other chemical witchcraft?

 

[Bioengineer01]

No, not correct, floor -2 (torus) and -1, look on the tepco flood drawings, they show clear those floors

Do you have a link to the tepco flood drawings?

 

[Borek]

Could Hydrazine have anything to do the steam/water vapor/smoke/whatever seen in the video? Like lowering the boiling point or some other chemical witchcraft?

If memory serves me well it is added in concentrations so low its presence shouldn't have any visible effect.

 

[shadowncs]

OT
just watched the http://www.tepco.co.jp/en/nu/f1-np/camera/index-e.html" wondering if it's not playing in a loop, things were so quiet. And there comes this badger-like animal going right on the roof to the right of the pipes & then jumps down and goes out of frame. Amazing. I'm convinced now the camera is for real :)

 

[jim hardy]

Thanks Elekrownik

the numbers on the photo are so blurry i can't make them out. i was seeing like 13 on right gage, didnt make sense. i hope they put up a clearer photo.

referring to their diagram and thinking real simple , as i have to ---

there's 0.18 mpa of water above right gage in addition to any pressure in reactor
so if it reads 0.18 mpa reactor is atmospheric alright ,,

and 0.1 mpa of water above left gage including what's in vessel
so the water level in vessel is at least 0.08 mpa lower than upper tap. Were it at upper tap the gages would read same.

mpa to feet of water?
for in my head calcs i use an atmosphere is close to 0.1 mpa and is 32 feet of water..
so 0.8 mpa is 0.08 X 32 = 25.6 feet?

i don't remember where the taps are relative to core. Will look for it. What's 25.6 feet below upper tap? Hopefully not the lower tap...

 

[elektrownik]

Do you have a link to the tepco flood drawings?

Yes, here: http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110530_04-e.pdf
There is drawing of - 2 and -1 of unit 6 which is abwr, but it is like unit 1 in case of underground floors, there was also separated drawing for unit 1 but I can't find it now...

 

[jim hardy]

If memory serves me well it is added in concentrations so low its presence shouldn't have any visible effect.

to my recollection its purpose is to scavenge oxygen. It's N2H4. it gives up hydrogen to combine with free oxygen or OH to make water molecules. It turns itself into ammonia(NH3) which you smell as you go by condenser air ejectors, and N2 and maybe H2 which you don't smell. it's a common boiler water additive for corrosion control, used because it's good for the boiler though pretty toxic to people in high concentration.
Since it turns itself into water and volatile gasses it doesn't measurably affect the usual properties of water.

old jim

 

[jlduh]

OT
just watched the http://www.tepco.co.jp/en/nu/f1-np/camera/index-e.html" wondering if it's not playing in a loop, things were so quiet. And there comes this badger-like animal going right on the roof to the right of the pipes & then jumps down and goes out of frame. Amazing. I'm convinced now the camera is for real :)
View attachment 36167

I've seen this animal several times on the webcam, the first time i was quite surprised!

Well this means that the area is not dangerous, right? A real nature park

 

[joewein]

What do you mean by basement when you refer to Unit 1? There is no basement below the PCV, just a concrete basemat? correct?
https://www.physicsforums.com/attachment.php?attachmentid=36166&stc=1&d=1307221110

See this Italian article that Jorge Stolfi posted a link to a while ago:
http://giappopazzie.blogspot.com/2011/05/post-tecnico-4-approfondimento-sulla.html

Here is the radiation map showing the 3-4 Sv/h hot spot where the video was taken in the bottom right corner.
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110604_01-e.pdf

Notice the tunnel / truck entrance at the left. That puts it at ground floor level (1F in Japanese terminology). Below that is the first basement (B1F in Japanese terminology). That is the space that holds the suppression chamber (torus). All of that space is flooded.

The bubbling could be from rising water levels that displace air / nitrogen down there, like the bubbling from a sinking ship gradually filling with water.

Alternatively it could be from nitrogen still being injected that somehow makes its way there.

The third possibility would be that the temperature down there is way higher than 50C. Maybe the thermocouples no longer show correct data if they're immersed in hot water all around? If there are 720,000 TBq in the basement water, what's the heat output from that?

 

[joewein]

I forgot a fourth possibility: The bubbling could be from a hydrogen/oxygen mix produce by radiolysis of water from that 720,000 TBq, but I have no idea what the expected volume per minute would be.

In any case, one would hope that if this was the case, there would be plenty of injected nitrogen at the same time to keep the hydrogen diluted below 4% or things could get ugly. The problem I see is that if N2 is injected into the RPV and from there flows into the dry well, it's not going to do much for hydrogen produced in the basement...