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.
  • #10,116
to (was it M'doc?) thought about explosion below decks

Did something change atop unit 3 in the first week ?



.....24(? i think) March..........16 March

4_moron.jpg


(ignore the label - it's nobody here.)


telephoto compression distorts perspective, so count rafters on the right side of main beam.
 
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  • #10,117
jim hardy said:
to (was it M'doc?) thought about explosion below decks

Did something change atop unit 3 in the first week ?



.....24(? i think) March..........16 March

4_moron.jpg


(ignore the label - it's nobody here.)


telephoto compression distorts perspective, so count rafters on the right side of main beam.

Are you sure you're looking at the same section of beam?
 
  • #10,118
Yes.
 
  • #10,119
SteveElbows said:
While we are waiting for full translation, here are some interesting press stories based on the document:

http://www.yomiuri.co.jp/dy/national/T110619002601.htm

http://search.japantimes.co.jp/cgi-bin/nn20110619x2.html

There are some interesting details covered by these stories, including the venting problem and some other things that went wrong as a result of explosions.

Man. The guy gets the battery from his car to power the valve to release pressure so they can inject water in No. 3. While nuclear reactor buildings explode from time to time. And earthquakes. In the dark.

Desperate measures in desperate times. I thought my job was hard. Hah! I am humbled. These guys are true heroes.
 
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  • #10,120
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  • #10,121
jim hardy said:
to (was it M'doc?) thought about explosion below decks

Did something change atop unit 3 in the first week ?

(ignore the label - it's nobody here.)


telephoto compression distorts perspective, so count rafters on the right side of main beam.

The red rings in this photo are simply wrong and misleading.

The photo on right actually shows the section of beam going all the way to the east end wall, not just to the position indicated by red ring in the left photo. The photo on right is shot from a lower angle, causing this mistake to be made.

Look at the more noticeable beam that goes south (going left on photo) and is near the bottom of the picture on the right. This is the same beam that is near the bottom of the left picture, not the one half-way up.

If you already know this, and were advising us to ignore the red rings, then I don't know what else is supposed to be different in these two pictures, nothing has changed at all.

Edited to add a picture showing how things actually line up, since I am not sure my words made sense.
 

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  • #10,122
An interesting take on the prospects for nuclear in China.
A senior researcher of the NDRC (National Development and Reform Commission) was interviewed at some length by 'Business China' here: http://en.21cbh.com/HTML/2011-5-11/yOMTc1XzIxMDEyOA.html

Takeaway was: nuclear is less bad than the alternatives and besides, Japan relied on antiquated reactors, badly located.
There was a nice dig at the safety of large dams in the interview, a gutsy move given the political support lavished on the Three Gorges project.
 
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  • #10,123
""'If you already know this, and were advising us to ignore the red rings, then I don't know what else is supposed to be different in these two pictures, nothing has changed at all."""

i do get frustrated by my clumsiness with "Paint" .

Indeed as you point out the left red ring should be dragged down until it grazes the east end of the beam, as does the right red ring. They are misaligned.

the angle of sunlight is different between the photos so illumination of the floor below the beams changed..

The feature i am interested in is not the beams but something underneath them, namely that black circle inside the ring in Mar 16 photo on right.
To me it looks like a hole in the deck below.
It is not visible in later photos.
It does show briefly in a March 15th helicopter video as mentioned a few pages ago..
around 1:10
so if it's an optical illusion it was there on two days.


What i was after is opinion on whether the black circle looks to anybody else like a hole in the deck. I sometimes suffer from what Mark Twain called "excess of imagination."
There seems to be plenty of photo expertise here. Perhaps somebody has another early photo or some enhancement tools that'd nail it yea or nay.

original is , again, at
http://cryptome.org/eyeball/daiichi-npp3/daiichi-photos3.htm
twenty-third one down.


jh
 
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  • #10,124
MadderDoc said:
Catching up to congratulate you for being the poster of the ten thousandth post to this thread!

This is not the first time we hit 10k, however, some posts were deleted/moved to other threads.
 
  • #10,125
jim hardy said:
<..>
Did something change atop unit 3 in the first week ?
.....24(? i think) March..........16 March
<..>
March 24th, yes.

Water was replenished to the pool over that period, so that's something that changed drastically, but probably not what you are hinting at.

I've found no evidence of structural changes in the remains of the roof metal structure since the explosion on March 14th, and also not between March 16th and 24th. I don't think there has been any such changes. If you've counted different number of beams in these two photos, there's probably one that has been missed. The slightly different angle could well make the beams closest to the camera hard to detect in these photos, then try counting from the other direction. I think you will find everything matches up.

Compared to the March 16th photo, the photo from March 24th features a readily apparent dark discoloration of beams, girders and pillars, assumedly from the recent fire on the evening of March 23rd:
20110323180100.jpg
 
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  • #10,126
biggerten said:
Man. The guy gets the battery from his car to power the valve to release pressure so they can inject water in No. 3. While nuclear reactor buildings explode from time to time. And earthquakes. In the dark.

Desperate measures in desperate times. I thought my job was hard. Hah! I am humbled. These guys are true heroes.

Absolutely!
 
  • #10,127
jim hardy said:
<..>
The feature i am interested in is not the beams but something underneath them, namely that black circle inside the ring in Mar 16 photo on right. To me it looks like a hole in the deck below.
It is not visible in later photos.

I too can make it look like a circle, but I am pretty certain it's an illusion, To make it look like a circle I need to blend in certain dark areas which via other photos can be identified as parts of material objects, not holes.

It does show briefly in a March 15th helicopter video as mentioned a few pages ago..
around 1:10
so if it's an optical illusion it was there on two days.


The date attribution is wrong for this video. Actually there are two videos there combined, including the video from which your photo was taken, both videos are from March 16th.
 
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  • #10,128
SteveElbows said:
The temperatures shown on the thermal images were not generally very high really. So I am not really sure that we have clear signs of a big source of heat in the reactor area.

Perhaps it is just heat from the sun that is stored in the water during the day and released at night.
 
  • #10,129
SteveElbows said:
The temperatures shown on the thermal images were not generally very high really.

The heat signature from that part of the building has generally been about 30oC, or appr. 30oC above ambient. See:
http://gyldengrisgaard.dk/fuk/thermal/thermala.html

So I am not really sure that we have clear signs of a big source of heat in the reactor area, but I admit some of the thermal images still interest me in this regard. Is it possible that we are just looking at the heat of steam that has blown in a northerly direction as it rises up from the pool? Or we are looking at water that is in the pit & reactor well area, but is not really very hot?

The signature indicates that going to sleep there on a stretcher across the reactor well on a freezing cold night during March or April, would have involved sleeping in a tropically warm and steamy environment at 30+oC. Certainly that needs an explanation.
 
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  • #10,130
Sounds probably silly, but...

What's with heat transfer from the pool to the RPV? Even if the gate's inteact, it should conduct heat.

So if there's 90+ degrees on one side and 20 degrees on the other, the other side is probably getting hotter.

MadderDoc said:
Catching up to congratulate you for being the poster of the ten thousandth post to this thread!

But we're still only the second largest thread in PF. https://www.physicsforums.com/showthread.php?t=63689" thread has 10560 posts.

400 posts to go for number one. :cool:
 
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  • #10,131
Jorge Stolfi said:
Perhaps it is just heat from the sun that is stored in the water during the day and released at night.

No, that's not possible. I foolhardily got in early summer mode and introduced a flock of reasonably cold resistant fish in my pond in late April, observing that a series of sunny days had managed to drive the water up to 15o. During the night weather changed, temperature dropped to the freezing point, and next morning the pond stood at 3o and not a fish was alive. If only it were so easy to stack solar heat for the night during the cold spring of the north temperate zone. If only.
 
  • #10,132
clancy688 said:
Sounds probably silly, but...
What's with heat transfer from the pool to the RPV? Even if the gate's inteact, it should conduct heat.
So if there's 90+ degrees on one side and 20 degrees on the other, the other side is probably getting hotter.

Surely that's something that could be estimated. The estimation should take into account not only the heat gain through the relatively small gate area, but also the heat loss through the disproportionately much larger remaining area interfacing with a colder atmosphere and supposedly colder reactor and containment structures.
 
  • #10,133
"""I too can make it look like a circle, but I am pretty certain it's an illusion,...""

thank you, that's what i was after - another opinion on the dark circle.

i can live with "it's ambiguous".

Indeterminate is after all a valid state.

thanks for the input.
 
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  • #10,134
jim hardy said:
"""I too can make it look like a circle, but I am pretty certain it's an illusion,...""
thank you, that's what i was after - another opinion on the dark circle.
i can live with "it's ambiguous".
Indeterminate is after all a valid state.
thanks for the input.

Personally I wouldn't say it is ambiguous. During the flight the video camera scans across the area in question, and in only a few frames there's this appearance of a circle. Skipping forward and backwards frame by frame It seems clear to me this effect is caused by the camera's looking through changing 'windows' in the rightmost steam plume caused by its swirling motion in the wind. It is easy enough to select a few frames in which it looks like there is a circle, but that does not mean one can cast away the great majority of frames in which nothing like a circle appears and it rather looks like there is a duck, a frog, Aladdin's jinni or something else or nothing but steam there.
 
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  • #10,135
clancy688 said:
What's with heat transfer from the pool to the RPV? Even if the gate's intact, it should conduct heat.

Yes, but until recently the water level on the reactor pit side of the gate was low, until they realized this removed radiation shielding for the steam dryer and cut-up shroud and topped it up.

While the water was low only the lower portion of the gate area would have transferred heat and the reduced water depth would have reduced convective transfer.


razzz said:
In the YouTube http://www.youtube.com/watch?v=lJjbNw07OUA" just after 7 minutes he says the shroud replacement was complete in Unit 4, according to his GE connections.

I noticed that too and then I saw someone post here that they were 5 months into a 10 month shroud replacement job. Unit 4 had been shut down either on November 29 or 30, depending on the source. The 10 months overall seem plausible, given it took more like 15 months the first time they replaced a shroud in Japan, but end of November to mid March is only 3 1/2 months.

TEPCO says the shroud in the tool bay was cut, so presumably that's the old one that had been cut up under water using plasma cutters and lifted out.

Toshiba writes that they surface-decontaminate all the metals using oxalic acid before starting the replacement. I don't think there can be a huge amount of decay heat from activated isotopes in the RPV steel or there would be a lot of gamma too and people couldn't be working in there during the repairs.
 
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  • #10,136
clancy688 said:
Sounds probably silly, but...

What's with heat transfer from the pool to the RPV? Even if the gate's inteact, it should conduct heat.

So if there's 90+ degrees on one side and 20 degrees on the other, the other side is probably getting hotter.
But we're still only the second largest thread in PF. https://www.physicsforums.com/showthread.php?t=63689" thread has 10560 posts.

400 posts to go for number one. :cool:

Not all data in this other long thread come from peer reviewed articles, it seems :tongue:

Being more serious, it seems they are moving a huge crane close to Building N°1, it's currently on Tepco webcam:

http://www.netimago.com/image_213177.html

http://www.netimago.com/image_213178.html
 
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  • #10,137
The crane at unit 1 most likely is for putting up the metal frame and polyester cover around the damaged building. Preparation work for it started on May 13, according to TEPCO.

Here's their plan:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110614e17.pdf

Recently TEPCO's workers have been practicing assembling and disassembling the cover at Onahama port. Assembly at Fukushima 1 unit is scheduled after disassembly is finished at Onahama.
 
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  • #10,138
Now appear to have a pump unit on reactor 1. Photo survey or water injection? Anyone have any insight?
 
  • #10,139
According to TEPCO, pool water injection is now done via the pool cleaning and cooling system at all units (unit 4 having been the last one to make the switch from concrete pumps on June 16).

I don't think they'll cast concrete foundations for the cover, otherwise they didn't have to go for this lightweight design. They'll use a more robust structure for the next layer, whenever that will arrive.

Camerawork is a good guess.

Oops, it's gone again!

EDIT: The crane is too small for erecting that cover, but it may be used for clearing the place for the other one.
 
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  • #10,140
joewein said:
The crane at unit 1 most likely is for putting up the metal frame and polyester cover around the damaged building. Preparation work for it started on May 13, according to TEPCO.

It could be the crane assembled by the worker who removed his mask for smoking :

According to TEPCO, the worker in his 50s was helping put together a crane on the morning of June 15 as part of preparations to build an enclosure around the plant's No. 1 reactor.
http://mdn.mainichi.jp/mdnnews/news/20110616p2a00m0na008000c.html
 
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  • #10,141
Is this the crane? I can't see it on the TEPCO feed. Screenshot taken at 09:45 GMT
crane.jpg
 
  • #10,143
zapperzero said:
Also, a report by TEPCO on the fact-finding expedition inside reactor #2.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110622_02-e.pdf

EDIT: 430 mSv/h at the bottom of the stairs leading to the first basement level.

The water is a sinister colour.

As for the crane around unit 1, its been doing stuff almost every day at unit 1 for some time now - often appears to be dangling a probe of some kind, though in locations that are not intuitive to me.
 
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  • #10,144
http://www.meti.go.jp/press/2011/06/20110622004/20110622004.html : The NISA agreed today with the request made by Tepco on 8 June to store more water in the Process main building :

OP5100 mm -> OP5600 mm
1.4 m above 1st basement floor -> 1.9 m
14,200 m³ -> 15,700 m³

http://www.bloomberg.co.jp/apps/news?pid=90920019&sid=a45S9fQOTF3A : this provides 5 more days of storing capacity, beyond the former 29 June expected overflow date.

http://www.yomiuri.co.jp/science/news/20110622-OYT1T00687.htm : the flows in the reactors are set as follows :

unit 1 : 3.5 tons/hour.
unit 2 : 4 tons/hour
unit 3 : 10 tons/hour
 
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  • #10,145
Yep, water levels are now such an issue that they've been reducing the amount pumped into the reactors in order to buy themselves a bit more time.
 
  • #10,146
http://www.asahi.com/national/jiji/JJT201106220097.html : The filtration efficiency of the absorption facility and the coprecipitation facility put together was found to be OK in the tests with highly contaminated water. The efficiency of the absorption facility is lower with highly contaminated water than during the tests with low contaminated water, but that is still high enough.
 
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  • #10,147
zapperzero said:
Also, a report by TEPCO on the fact-finding expedition inside reactor #2.

http://www.tepco.co.jp/en/nu/fukushi...10622_02-e.pdf

EDIT: 430 mSv/h at the bottom of the stairs leading to the first basement level.
Thank you for the link.

This weird color of the water looks to me like rust. It's just the same color you get when you have various sorts of scrap metal rusting in aggressive water.
Remember there are many different metals there and this can boost the rusting speed to a nearly explosive pace.
Just think of how fast the Komsomoletsk dissolved due to the titanium-steel rusting catalytics.

The saturation of the water with whatever dissolved in it appears quite high, as it is completely opaque.

Hope they will publish a chemical and radiological analysis of that liquid soon.

And, when I looked at the picture in detail, I noticed that the water level originally has been a few cm higher.
And the water apparently was originally not that intensely saturated with that brown stuff, as you can barely recognize the original flooding mark.

Could an explanation for these observations be that there is an opening at the height of the water level where the water flows off to somewhere else?
Could the observation of a higher original water level be caused by a widening of such an initial opening, maybe because insulation or other debris in the way has been swept away by the water flow?
 
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  • #10,148
Atomfritz said:
This weird color of the water looks to me like rust.

There should be plenty of rust, given how salty the water is. I saw one report that the salt contents of the liquid in the basements still is 50-80% of that of sea water. Also, the relatively high temperature from the decay heat will accelerate the reaction speed.

Once they pump out salty radioactive water, treat it and pump it back as almost clean water, this will lower the salt contents, but will probably take a very long time to bring the NaCl concentration down to levels comparable to fresh water, as it will just dilute and dilute it.

Anything already touched by salt water will keep a slight salt crust when the liquid level drops. Anything already rusty will continue to draw moisture from the air (rust seeks moisture), which will keep the rust growing. I can't help wondering what the basements will look like in say 5 years from now. Will there be any metal staircases left?

The salt water contamination and resulting corrosion also has implications for units 5 and 6, which TEPCO has not officially written off as not restartable yet, and for Fukushima Daini which TEPCO would also like to bring online again ASAP.


Atomfritz said:
And, when I looked at the picture in detail, I noticed that the water level originally has been a few cm higher.

Perhaps some water was pumped from the turbine hall basement, since the reactor building basement and turbine hall basements are connected.


The 430 mSv/h at the bottom of the stairs was pretty interesting. TEPCO is talking about drilling holes through the floor to near the torus, to fill the space around it with a cement/sand mix. A bit like drilling a hole down into hell...
 
  • #10,149
SteveElbows said:
The water is a sinister colour.

Doesn't that give a pretty good idea of where the reactor and the fuel ponds are, at least for building 2? The containment is structure is hug!
 
  • #10,150
joewein said:
The 430 mSv/h at the bottom of the stairs was pretty interesting. TEPCO is talking about drilling holes through the floor to near the torus, to fill the space around it with a cement/sand mix. A bit like drilling a hole down into hell...

And a bit like pouring concrete over the scene of an accident while the investigation is ongoing.
EDIT: Can't be helped, I suppose, not if they want closed loop cooling. But still.
 

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