Japan Earthquake: nuclear plants


by gmax137
Tags: earthquake, japan, nuclear
Lambert
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#8785
Jun4-11, 04:53 AM
P: 21
Quote Quote by razzz View Post
Fascinating.
So true, what do you expect though? Cheers!
elektrownik
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#8786
Jun4-11, 05:00 AM
P: 296
Quote Quote by elektrownik View Post
http://www.tepco.co.jp/en/news/11031.../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/fukushi...10602_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-..._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
GJBRKS
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#8787
Jun4-11, 05:38 AM
P: 82
Quote Quote by Borek View Post

Is it confirmed it is boiling, or do you just guess it boils because it is steaming?
Not sure if it's water or photons on the CCD ?

Could be the CCD , but seems like waterbubbles ?

http://www.tepco.co.jp/en/news/11031.../110604_09.zip

[EDIT] Hmmm , on third look they do seem to be waterbubbles ...( from 0:20 sec onwards)
MadderDoc
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#8788
Jun4-11, 05:56 AM
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Quote Quote by GJBRKS View Post
Not sure if it's water or photons on the CCD ?

Could be the CCD , but seems like waterbubbles ?

http://www.tepco.co.jp/en/news/11031.../110604_09.zip

[EDIT] Hmmm , on third look they do seem to be waterbubbles ...( from 0:20 sec onwards)
Yes, it would seem too far fetched to say these are CCD artefacts..

Only two explanations seem to me consistent with what we see
a) boiling water
b) gas mixture escaping through water, either or both of which hot.
MadderDoc
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#8789
Jun4-11, 06:06 AM
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Quote Quote by robinson View Post
So, is the cesium a metal or an oxide?
Coming out of a nuclear reaction, presumably cesium atoms (metal) as well as a multitude of cesium ion species could be initially formed, however with cesium ion Cs+ being likely the only chemically stable end product.
imandylite
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#8790
Jun4-11, 06:30 AM
P: 22
Packbot video of Steaming pipe junctions - ground floor reactor unit 1



Or - is it boiling?
AntonL
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#8791
Jun4-11, 06:49 AM
P: 521
Quote Quote by imandylite View Post
Packbot video of Steaming pipe junctions - ground floor reactor unit 1



Or - is it boiling?
http://www3.nhk.or.jp/daily/english/04_16.html
TEPCO said it found that steam was rising from a crevice in the floor, and that extremely high radiation of 3,000 to 4,000 millisieverts per hour was measured around the area. The radiation is believed to be the highest detected in the air at the plant.

TEPCO says the steam is likely coming from water at a temperature of 50 degrees Celsius that has accumulated in the basement of the reactor building.

The company sees no major impact from the radiation so far on ongoing work, as it has been detected only within a limited section of the building
The steam generated in the reactor must go somewhere, that it is from 50oC water in the basement is possibly the simpler and non alarmist message
westfield
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#8792
Jun4-11, 07:02 AM
P: 143
Quote Quote by elektrownik View Post
You can see on tepco video that water is boiling
http://www.tepco.co.jp/en/news/11031.../110604_09.zip when robot zoom to hole
FWIW I'm not convinced by the footage, the quality just isn't good enough to see properly. Looking in slow mo at the darker patches, the "water", just doesn't look to me like boiling fluid. More like artifacts I thought.

But also, for it to be visible boiling fluid wouldn't two levels of basement need to be completely and totally flooded to the ceilings? If it was totally flooded and boiling would it just quietly percolate at that pipe penetration or would it be burping water and steam out of that hole much more actively?

Whatever it is or isn't, it's still not a good thing to have going on obviously.
swl
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#8793
Jun4-11, 07:44 AM
P: 108
Regarding the bubbling steam video:

If those are gas bubbles boiling up in the video, they could also be from Nitrogen gas being injected, or air entrained in a water injection or circulation system.
Is TEPCO still injecting Nitrogen into unit 1? If so, does anyone here know the injection point?

Could also be gas, including steam, bubbling up from the RPV via way of it's ventilation path through the torus. Or gas from the boiling lump in the bottom of the dry well, or... nevermind.

And as for the water could it be just water standing in a drain under a steam trap? Are we sure the water in video represents the 50* water in the "basement"?

It looks quite hot to me, but I can imagine too many possibilities to make the video of much use to me.

The high radiation readings sound bad to me, but I'm comforted to hear TEPCO is not overly concerned.
robinson
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#8794
Jun4-11, 08:12 AM
P: 201
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.
Bioengineer01
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#8795
Jun4-11, 08:25 AM
P: 123
Quote Quote by robinson View Post
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.
Can somebody disprove this?

My Hypothesis: Water is in contact with Superhot Corium somewhere in the basement, a layer of vapor exists around the Corium, the outside layer of that superhot vapor is finding its way to the surface through the rest of the water in the basement, that is at 50 C on the average near the surface, where they are probably measuring its temperature.
robinson
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#8796
Jun4-11, 08:28 AM
P: 201
From a physics point of view, what material could be producing that high level of radiation in the water vapor we see in the video?
Bioengineer01
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#8797
Jun4-11, 08:28 AM
P: 123
http://www.chrismartenson.com/blog/e...58689#comments
Arnie Gundersen says that Units 1 and 2 can not get any worse because the worst already happened... He also says that the Corium can not achieve re-criticality... That is not what I thought, can somebody clarify this?
Also he makes no mention of the large increase in Iodine-131/Cesium-137 that we saw inside the silt fence of Unit2, I think that the 28th of May... He doesn't think that the Corium will ablate through the concrete. He doesn't say why he thinks that way.

He says that Unit 3 is starting (getting critical) and stopping all the time and can still get a lot worse if the fuel melts through and suddenly falls on water.

He is also concerned about unit 4 SFP crashing. And about the ground water being contaminated by radioactive material.
Borek
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#8798
Jun4-11, 08:43 AM
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Quote Quote by robinson View Post
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
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#8799
Jun4-11, 08:49 AM
P: 123
Quote Quote by Borek View Post
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
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#8800
Jun4-11, 08:49 AM
P: 201
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
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#8801
Jun4-11, 08:59 AM
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Quote Quote by robinson View Post
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
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#8802
Jun4-11, 09:04 AM
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Quote Quote by AntonL View Post
http://www3.nhk.or.jp/daily/english/04_16.html


The steam generated in the reactor must go somewhere, that it is from 50oC 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 50C in order to prevent contaminated steam from rising into the atmosphere ?


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