Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[rowmag]

OK, then if it's the basement where the torus is, where is the torus on the picture?

Ok, not basement level. Ground level:

[URL]http://www.tepco.co.jp/nu/f1-np/intro/outline/images/mark1.gif[/URL]

(Mark I cross-section from OnlyOneTruth's link to TEPCO site: http://www.tepco.co.jp/nu/f1-np/intro/outline/outline-j.html.)

 

[M. Bachmeier]

Does anyone know about the use of hydrogen peroxide in BWR's during shutdown. I'm interested in storage (in or out of reactor building), added concentrations in reactor and SFP.

For example:

"Appropriate biocides (hydrogen peroxide) at concentrations up to 1000 ppm were added (to the pool water) to control biofouling."

From: http://www-pub.iaea.org/MTCD/publications/PDF/te_0944_scr.pdf

Also anyone with knowledge about what chemicals might be stored/used (in or near reactor) during BWR shutdown that might interact with hydrogen peroxide (powerful oxidizer).

I have a feeling that hydrogen peroxide may have played a role in the explosion at the Fukushima Diiachi #4 reactor building.

 

[I_P]

The expertise deployed on this forum to understand the processes which reduced four multi billion dollar reactors to steaming scrap is laudable.
For an outside observer, it would be wonderful if this expertise were also employed looking forward, to help evaluate and understand the challenges and risks posed by the clean up plan.
For instance, Areva is scheduled to have a water processing plant built by the end of June that will process 1200 tons of water/day. There are nearly 70,000 tons currently in the facility, increasing at 500tons/day, so there will be 100,000 tons by the time the plant is operational.
The plant will start to whittle down the flood at about 700 tons/day net once it starts, so it will take 150 days to drain the facility, if all goes well.
That says the cleanup will not begin until very late this year at the earliest.
Is this a plausible schedule? How does it tie into the TEPCO indication that the immediate crisis should be stabilized within 9 months? What are the risks that should be of most concern?

My assessment, FWIW, is that TEPCO was mandated by the government to come up with a plan - so they have, in consultation with experts in and outside of Japan. Given what they know about the state of affairs, the plan is a reasonable place to start. However, working against them are: they don't yet appear to have a clear idea of the state of damage to the reactors (and the four units each have different problems). High radiation levels remain an obstacle to good assessment and will hamper remediation efforts. They really need access by workers to execute the cooling plan; There is a continuing threat of more aftershocks causing further damage and complications; failure of the cooling system now in place could lead to additional release of radiation and change the ground rules; because the state of damage is unknown there is always the possibility that, despite the current appearance of stability, processes at work in the reactors and fuel storage areas could lead to currently unrecognized problems.

This article from Asahi lays some of it out:
http://www.asahi.com/english/TKY201104190193.html"

I would also say that the nuclear power community as a whole does not have a clear idea of how to proceed with so many unknowns - the problems faced are quite difficult and appropriate tools and procedures are lacking. Look at the debate on the pool chemistry taking place here and elsewhere - its all a 'grand' experiment - both fascinating and terrible at the same time.

 

[rowmag]

Chronology also contains links to documentation of security audits, the second PDF on http://www.tepco.co.jp/nu/f1-np/press_f1/2008/htmldata/bi8a07-j.html is an appendix to a 2008 audit of No4 with loads of data and some visual documentation. I'll add two thumbs as a teaser:

The first one is a suppression chamber strainer that they replaced.
The second one is inspected points on the jet pumps that are arrayed around the outside of the shroud.

Looks like they found a leaking fuel assembly. See page 26:
http://www.tepco.co.jp/nu/f1-np/press_f1/2008/pdfdata/bi8a09-j.pdf

Would something like that have been left in the SFP after replacement, or would it have been stored in isolation somewhere else?

 

[ascot317]

it is impossible to predict anything there imo. I would of never thought they'd be using 2 robots, one with radiation monitor strapped to it, other to look at the monitor, 38 days in, versus some KHG robot.

Especially this being Japan.
I mean look at that:


I can't figure out how they suddenly seem to be a 3rd world country in terms of technology.

 

[Dmytry]

Especially this being Japan.
I mean look at that:


I can't figure out how they suddenly seem to be a 3rd world country in terms of technology.

article from 2000:
http://search.japantimes.co.jp/cgi-bin/nn20000413b5.html
they canceled the project within a year under notion that they don't need that.
Both Germany and France offered robots ages ago.

 

[Joe Neubarth]

I am quite a few pages behind, but before I go to bed, I wanted to ask to see if I am out in left field with a broken mitt.

TEPCO is still pouring water into the top of Reactor Two. Days ago there was steam flowing out to assure us that the reactor core was being cooled.

Now, the water is not reaching the core as no steam is being generated, but hot gases are erupting from the reactor as if it was a volcano.

Dudes, is this the beginning of a China Syndrome situation. Where the 'ell is the core? Maybe somebody has already answered this, if the water always seeks lowest ground and the core is going down as it melts what else could be happening? The Core went right and the water is going left or vice versa? How?

Is the core in the Earth under the plant and debris has fallen in on it and the water has flushed a path to the sea or some underground pocket...

 

[Dmytry]

i think core is in RPV cooking itself, and I think consequences of this may - in worst case - leave you wishing that it just melted through and mixed with some molten concrete etc, blown itself apart, or did something else that'd make it cook colder. I really have no idea into what fractions the corium is going to fractionally distillate itself, and I do not want to get educated on this topic by experimental data. I only know that the hotter fuel cooks, the more stuff gets out of it, and I estimate it can boil itself. Literally.

 

[MJRacer]

From

don't know if the whole of this vid has been posted before?

at about 51 seconds

image stabilised t-hawk video?

at about 2:05

Why does it look like this?:

Notice how close the top of the reactor is to the outside wall in Mark I containment systems:

I have marked in red the part of the drywell that seems to have been blown away. But, if so, how?!

 

[hoyrylollaaja]

From



at about 51 seconds



at about 2:05

Why does it look like this?:

Notice how close the top of the reactor is to the outside wall in Mark I containment systems:

I have marked in red the part of the drywell that seems to have been blown away. But, if so, how?!

That is the control room, supposed to be at high SW corner of RB.

 

[|Fred]

Now, the water is not reaching the core as no steam is being generated, but hot gases are erupting from the reactor as if it was a volcano.

where did you see that , I must admit i no longer watch nhk 247 (especially since they resume regular program)

 

[ascot317]

From



at about 51 seconds



at about 2:05

http://i55.tinypic.com/mskgid.png

Why does it look like this?:

http://i53.tinypic.com/2jcj1hd.jpg

Only that it doesn't look like this and is nowhere close to it. Look a few frames back and forth. The Drywell is >10m wide and round, the piece in the video isn't.

 

[|Fred]

From
Why does it look like this?:

It does not, and it is not.
I can not be 100% positive that it is the floor control basement the only picture we have for this control room are from unit 3 an do not match

 

[MJRacer]

That is the control room, supposed to be at high SW corner of RB.

The object I have circled in red looks like it is round and does not appear to be in the corner, but away from both walls a certain distance.

Here is appears to be a picture of the control room:

where the floor control rooms gone ? supose to be in the south west corner but the remains do not seems to fit the structure

 

[MJRacer]

Only that it doesn't look like this and is nowhere close to it. Look a few frames back and forth. The Drywell is >10m wide and round, the piece in the video isn't.

Exactly. The drywell appears to be completely gone and it appears as if we are looking right at the stainless steel reactor vessel (sans yellow cap).

 

[ascot317]

Exactly. The drywell appears to be completely gone and it appears as if we are looking right at the stainless steel reactor vessel (sans yellow cap).

No, not exactly. I'm saying your observation is wrong. This isn't a part of the drywell. And it's surely not a part of the pressure vessel. AND the yellow cap isn't part of the pressure vessel, either, it's part of the drywell/containment.

 

[MiceAndMen]

I have marked in red the part of the drywell that seems to have been blown away. But, if so, how?!

In your first picture you can see the drywell cap in the background (yellow). It is sitting on the floor of the refueling level in the reactor building. That floor is several meters above the top of the drywell cap when it's in place. There is no part of the reactor or drywell vessel high enough to block the view of the yellow cap when it's removed and on the floor.

As for the second and third pictures, at that point in construction the reactor vessel would not be in place yet. The middle picture shows the upper part of the drywell sticking up out of the construction site. Whatever the bulky thing in the top picture is, it's not part of the drywell or reactor vessel.

 

[razzz]

Everything is not totally wasted. Things could be worse, another good sized earthquake could finish off SFP 4 or even cause more junk to fall into it including the other pools. It flood and bleed for now, I don't think corium is traveling freely as the flooding along with nitrogen injection is preventing Unit 1 from freaking out again. 2 & 3 sitting might as well be sitting in a overflowing swimming pools but with such high contamination readings you can't do any meaningful work on any of them until they cool down.

TEPCO seems the most worried about Unit 4's pool so you know where their head is at.

They need to convert a Bobcat simulator(s) to real-time viewing/controls and keep cleaning up using remote operators before attempting the big stuff. If they can keep the contamination mostly localized anything escaping will hopefully just dilute in the air and water. Just don't need any more big event's.

I notice the think tank on this forum is pretty much silent and they are in the industry so they might know more than they are willing to say. Can't blame'em.

 

[MJRacer]

In your first picture you can see the drywell cap in the background (yellow). It is sitting on the floor of the refueling level in the reactor building. That floor is several meters above the top of the drywell cap when it's in place. There is no part of the reactor or drywell vessel high enough to block the view of the yellow cap when it's removed and on the floor.

As for the second and third pictures, at that point in construction the reactor vessel would not be in place yet. The middle picture shows the upper part of the drywell sticking up out of the construction site. Whatever the bulky thing in the top picture is, it's not part of the drywell or reactor vessel.

Thanks and in reply to all, I see that now. My apologies for the bandwidth.

 

[M. Bachmeier]

I notice the think tank on this forum is pretty much silent and they are in the industry so they might know more than they are willing to say. Can't blame'em.

No I think they just decided to finally get some sleep. Now if the tornadoes would just go away I could get some sleep too.

 

[hoyrylollaaja]

The object I have circled in red looks like it is round and does not appear to be in the corner, but away from both walls a certain distance.

Here is appears to be a picture of the control room:

just take away that pilar holding it up and turn it sideways, voilá.

 

[MiceAndMen]

Thanks and in reply to all, I see that now. My apologies for the bandwidth.

No problem, we're all just trying to understand what all the pictures, videos and assorted other data are showing.

No I think they just decided to finally get some sleep. Now if the tornadoes would just go away I could get some sleep too.

Stay safe.

 

[PietKuip]

This article from Asahi lays some of it out:
http://www.asahi.com/english/TKY201104190193.html"

The "puddles" are 5 meters deep now:
"Officials of the Nuclear and Industrial Safety Agency (NISA) said April 18 that a pool of water about five meters deep had been found in the basement of the building housing the No. 4 reactor.

Radiation levels as high as 100 millisieverts per hour were detected on the water's surface.

About 54,000 tons of radiation-contaminated water also sits in the basements of the turbine buildings for the No. 1 to No. 3 reactors. "

And that is where the missing radioactivity of the Unit 4 SFP went.

 

[|Fred]

It is inside picture of the Kariwa Tepco Power plant Fuel pool taken by a security camera before and after the Niigata-Chuetsu-Oki Earth quake in 2007
http://www.tepco.co.jp/en/niigata/plant/jisho02-e.html
[URL]http://www.tepco.co.jp/en/niigata/plant/images/jisho02/k3001.jpg[/URL]
[URL]http://www.tepco.co.jp/en/niigata/plant/images/jisho02/k3002.jpg[/URL]

Tepco building seems so be strainer when in comes to holding water..
on the above occasion watter steered out of the out the pool found its way to the ocean..
[URL]http://www.tepco.co.jp/en/niigata/plant/images/jisho04/k6003.jpg[/URL]
http://www.tepco.co.jp/en/niigata/plant/jisho04-e.html

 

[MadderDoc]

<..>The stuff on the facade of the turbine building is laying over the edge, not damage from an outward blast. The smoke that looks to be coming from the east side of Bldg 4 is coming from the stack I guess. And the debris are from Bldg 3. So, BTTDB . . .

The 'smoke' is not smoke it is steam. We know #3 had puked up just a few minutes ago. We know that _a larger area_ around it must have been soaked by water from it. Hot water. So, no surprise, we see steam coming from that area...

But soon that steam dissipated. Webcam about an hour later:

I'm not even sure one can see, that it is still smoking a bit from the top of unit 3, but it did.

 

[rowmag]

Looks like they found a leaking fuel assembly. See page 26:
http://www.tepco.co.jp/nu/f1-np/press_f1/2008/pdfdata/bi8a09-j.pdf

Would something like that have been left in the SFP after replacement, or would it have been stored in isolation somewhere else?

Following up to myself: From page number 8 (PDF page 10) of http://www.tepco.co.jp/nu/f1-np/press_f1/2008/pdfdata/bi8a08-j.pdf, they report that a suspected leaking fuel assembly in the core had been identified during operation in 2007, I gather by sliding different sets of control rods in and out with the plant running at reduced output until they managed to get the leaked radioactive gas to stop being produced. They isolated that assembly by inserting the control rods around it, and went back up to full power until the scheduled maintenance/inspection period in 2008. When they eventually pulled the suspect assembly out, it showed no visible signs of damage, but they treated it as a spent fuel assembly and did not re-use it.

Which doesn't exactly answer my question, but perhaps suggests it was placed into SFP4?

(Not sure this tells us anything, though, unless it gives NUCENG some bright idea...)

 

[Krikkosnack]

Building 4 has already exploded. Two panels have blasted out of the east side and impacted on the west facade of the turbine building for Unit 4, and smoke is pouring out of the east side of Building 4. Your eyes aren't looking for it because you know this is "before" the explosion. But the impacts on the turbine building are real. They weren't there before the explosion.

https://www.physicsforums.com/attachment.php?attachmentid=34633&d=1303253626

after the https://www.physicsforums.com/showpost.php?p=3255144&postcount=4231", it's what i saw 5 minutes later , analyzing the possible trajectories. You can see on the pipe, there is the blue color of the wall attached to the cement, that can't come from the reactor 3. But, if you look well, the edge of building in front of the reactor 4 was already broken before the "possible explosion" of reactor 4

 

[Borek]

after the https://www.physicsforums.com/showpost.php?p=3255144&postcount=4231", it's what i saw 5 minutes later , analyzing the possible trajectories. You can see on the pipe, there is the blue color of the wall attached to the cement, that can't come from the reactor 3. But, if you look well, the edge of building in front of the reactor 4 was already broken before the "possible explosion" of reactor 4

Your yellow trajectories don't take into account visible tracks on the turbine building roof - it looks like whatever felt through the roof to the inside of the building was first sliding and didn't get through till it slowed down enough.

 

[clancy688]

https://rapidshare.com/files/458267452/Upload_Refs.zip

let me know if I did this right.

Thank you very much, it worked. :)@TCup

As for the bldg 4 "explosion before the explosion" - I mentioned nearly the same a couple of days ago... ^^

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

This image was taken on March 14th - but I don't know the exact time zone and the exakt time. Sources report an explosion in Unit 4 in March 15th, 6am, which destroyed two panels - that's consistent with your observation on this sat image.
If the satellite was taking images at US standard time, it's over half a day behind the japanese time. So it could be possible that this image is covering March 15th. But the shadows are not long enough and are coming from southsoutheast - I think the picture was taken around 10-12am March 15th japanese standard time...

http://www.reuters.com/article/2011/03/15/japan-nuclear-holes-idUSTFD00668920110315

 

[Krikkosnack]

Your yellow trajectories don't take into account visible tracks on the turbine building roof - it looks like whatever felt through the roof to the inside of the building was first sliding and didn't get through till it slowed down enough.

I saw the trajectories of dust on the turbine building roof but i didn't condidered, because only the weight of the masses cannot "break" the roof (as you suggest that it was "sliding" upon it). Maybe something very very hot but i don't remember (from the thermal images). Why don't you suggest graphically, as TCUP did, some trajectories?

 

[Dmytry]

the teoretizing about collateral damage from reactor 3: how reactor 3 tore reactor 4 bldg apart but not reactor 2 bldg? Which is, incidentally, at the most destroyed size of reactor 3.

 

[tsutsuji]

Beginning to sound promising... actual plan with numbers in!

from the new york Times:-

"Anne Lauvergeon, the chief executive of Areva, France’s nuclear power equipment provider, said at a news conference in Tokyo on Tuesday evening that it would take at least until the end of May to set up a water treatment station at the Fukushima nuclear plant and begin purifying water. Once running, the water treatment facility should be able to handle 50 metric tons of water an hour and will be able to reduce the radiation in the water by 99.9 percent to 99.99 percent.

Ms. Lauvergeon said that even having the system up by the end of May would pose a big challenge. “It is a fight against time, but we are doing everything in our power” to meet this timeline, she said. "

some more here :

In a process called co-precipitation, the water will be treated with chemicals that cause radioactive material to settle out.
...
By contrast, a floating treatment facility built by Japan and Russia for water with low-level radioactive contamination has a capacity of only 7,000 tons a year.
http://e.nikkei.com/e/fr/tnks/Nni20110419D19JFA25.htm

 

[MadderDoc]

<..>

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg

This image was taken on March 14th - but I don't know the exact time zone and the exakt time. <..>

It is from 02:04 GMT, or 11:04 JST. That is 3 minutes after the steam explosion of unit 3.

In the attached zoom out you can see the plume of steam from the hot water expelled over the area, drifting out over the ocean and as a haze around unit 3 and 4, and the attached turbine buildings.

In the attached zoom in, you can see up closer the steam haze from the expelled water still hanging around unit 3, and, from the center of unit 3, get a clearer view of the distinct, less transient, and more bluish white smoke/steam fan from the leaking reactor containment.

 

[Astronuc]

Following up to myself: From page number 8 (PDF page 10) of http://www.tepco.co.jp/nu/f1-np/press_f1/2008/pdfdata/bi8a08-j.pdf, they report that a suspected leaking fuel assembly in the core had been identified during operation in 2007, I gather by sliding different sets of control rods in and out with the plant running at reduced output until they managed to get the leaked radioactive gas to stop being produced. They isolated that assembly by inserting the control rods around it, and went back up to full power until the scheduled maintenance/inspection period in 2008. When they eventually pulled the suspect assembly out, it showed no visible signs of damage, but they treated it as a spent fuel assembly and did not re-use it.

This is pretty standard in the industry with respect to BWR failures. An operating failure can be found by inserting a control blade adjacent to the failure. During the process, the off-gas (Xe-133, Kr-85m, Kr-87, Kr-88, Xe-135/135m, Xe-138) activity is monitored for changes. A reduction in activity indicates a possible leaking fuel assembly.

The process has been called 'flux-tilting'. The process was codified about 18 years ago and is now generally called power suppression testing (PST). Once the failure is located the local control blade is inserted, and others maybe inserted as well in order to reduce the power in the failed assembly. Most utilities prefer to shutdown the reactor in a mid-cycle outage to remove the failed assembly.

It is policy not to return a failed assembly or one suspected as failed to the core.

Meanwhile the industry has been working to achieve zero failures in LWR fuel.

 

[clancy688]

It is from 02:04 GMT, or 11:04 JST. That is 3 minutes after the steam explosion of unit 3.

So the damage TCups pointed at at the turbine building facing Unit 4 was already there three minutes after Unit 3 exploded?

11:01 JST / March 14th - #3 explosion:

11:04 JST / March 14th - Sat images show extensive damage to building #3 AND two damaged spots at the turbine building facing #4.

6:00 JST / March 15th - first explosion at #4 ejects two wall panels and damages #3 further (according to TEPCO)

9:40 JST / March 15th - fire in SFP at #4So the damage TCups pointed out was already there before Unit 4 exploded... Maybe it did come from Unit 3 after all?