Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[ascot317]

I've aligned the sat and the uav pictures somewhat, additionally I drew some lines (they're not 100% exact).

http://min.us/lkC3Tm

 

[tsutsuji]

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.

What is a KHG robot ? I can't find it on acronymfinder.com.

 

[|Fred]

But the impacts on the turbine building are real. They weren't there before the explosion.

You cached something , but I do not thinks it is what you were hoping for. From the geoimage, missing the alleged blasted panel from Building 4 , is.
And where you see Impacts, I see pieces of tar from Building 3.
Keep hunting :)
[PLAIN]http://img864.imageshack.us/img864/5538/tartroof.jpg

ps: http://min.us/lkC3Tm .. I need to learn to present things in a tiny manner like this...

 

[NUCENG]

What is a KHG robot ? I can't find it on acronymfinder.com.

http://www.dw-world.de/dw/article/0,,14958794,00.html

 

[|Fred]

What is a KHG robot ? I can't find it on acronymfinder.com.

Na Ja das ist aber Deutsch vür Kerntechnische Hilfsdienst GmbH
http://www.khgmbh.de/wEnglisch/intro_fernhantierung.php

 

[robinson]

YouTube user Anjiin it would seem, works in a Japanese nuclear plant, and years ago uploaded a lot of mundane videos from inside the reactor area.

http://www.youtube.com/user/Anjiin#p/u/10/eJeEka0qcng

I see Fukushima Prefecture listed in the descriptions.

TU-1(BWR) Tsuruga-shi.Fukui Pref. JAPAN
The removal work of FW

https://www.youtube.com/watch?v=eJeEka0qcng

Don't know the relevance, but there they are.

This one seemed quite interesting.

https://www.youtube.com/watch?v=DDE3pqEBfU8

 

[tsutsuji]

http://www.dw-world.de/dw/article/0,,14958794,00.html

Thanks.

"Areva is also currently training in France Japanese technicians from Atox, a Japanese nuclear site intervention company, to the handling of specialized robots, enabling them to later enter in action in Fukushima" :

Areva forme en outre actuellement en France des techniciens japonais de la société nippone d’intervention sur sites nucléaires Atox à la manipulation de robots spécialisés, afin de leur permettre d’entrer ultérieurement en action à Fukushima.

19/04 2:57 p.m. CET

http://fr.euronews.net/depeches/872...ge-de-la-decontamination-de-leau-radioactive/

 

[Dmytry]

Thanks.

"Areva is also currently training in France Japanese technicians from Atox, a Japanese nuclear site intervention company, to the handling of specialized robots, enabling them to later enter in action in Fukushima" :

I wonder why it makes me think that they are not permitting pre-trained foreign experts to do it. It's 40 days in. They got 2 bots, one with consumer grade radiation monitor by the look of it, other to look at the readings.
For KHG, see this: http://www.khgmbh.de/wEnglisch/unternehmen_film.php?navanchor=1010039

 

[Krikkosnack]

another alignment of the reactors..
[URL]http://blog.bottomlessinc.com/wp-content/uploads/2011/04/fukushima_reactor_3_total_destruction.jpg[/URL]

 

[ascot317]

I wonder why it makes me think that they are not permitting pre-trained foreign experts to do it. It's 40 days in. They got 2 bots, one with consumer grade radiation monitor by the look of it, other to look at the readings.
For KHG, see this: http://www.khgmbh.de/wEnglisch/unternehmen_film.php?navanchor=1010039

Their "EROS" robot is nice. Dose rates of 10^2 Gy/h, Max Dose Rate 10^4Gy, ability to climb stairs, that should do for some scouting.

The KHG guys must be pissed to see what's currently happening in Japan. Imagine you have all these tools at hand and then you see the someone operating two robots with a counter taped to one and a camera on the other. I'd be fuming.

I can't figure out why they haven't pinned a cam to a boom yet to check the inside of 3/4. I mean, what we've seen of it is laughable. I'm very curious to see what's in #3 and how #4 is looking on the inside.

 

[PietKuip]

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?

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

With all respect for Areva and their experience with fuel reprocessing and without being a chemist myself, I think this is way too optimistic about the future. It would take time even to build a plant for decontaminating fresh water. Maybe that can be done within a few months.

But how to handle cesium in salt water? Does co-precipatation using nickel ferrocyanide work in brine? Won't most of the precipatate contain other stuff than cesium? Are there any radiochemists here?

 

[MadderDoc]

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.

Yes. The spots must be from something spewed out by #3, however I am not sure how much damage those particular spots would represent. The fall-out of #3 was a bit like when you sift grain in the wind, the lightest stuf blows away, the medium dense objects ends like a fan on the ground in the wind direction, and the densest stuf ends fortunately -- or unfortunately in the case of #3 -- right back in the basket.

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

Right. I think the explosion in #4 on the 15th caused very little damage to #3. I've attached a photo taken from the distance one and half hour after the explosion of #3, at 12:40 JST / March 14th. It looks to me in the large structures of it, to be then as it is now.

9:40 JST / March 15th - fire in SFP at #4<..>

Yes, but that's only part of it. The 15th and 16th were dreadful days at #4, really horrible, one can easily imagine. You can see the hourly webcams from those days at:
http://www.gyldengrisgaard.dk/tepcowebcam/

 

[PietKuip]

http://www3.nhk.or.jp/daily/english/20_30.html

In the video, NHK says that radioactivity increases in the basements of units 5 and 6. The contaminated water is spreading all over the place.

 

[rowmag]

Following up to myself: From page number 8 (PDF page 10) of http://www.tepco.co.jp/nu/f1-np/pres...a/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.

I thought it sounded pretty clever.

Thanks for the info.

 

[Joe Neubarth]

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

That is amazing! Something so very obvious as the data from Reactor Two and nobody appears to understand what is happening.

Reactor Two is at Atmospheric pressure. Reactor Two has tons of water being poured into it. Reactor Two is NOT venting steam.

In fact the top of the reactor is considerably higher than the temperature of steam. Steam can only go to a higher temperature if it is under pressure, which it is not in this case. Reactor two is venting hot radioactive gases.

So,I ask my question in the morning that I asked at night. Does anybody have any theories as to how the water is missing the core which has to be out of containment at this time. Are we going to see a continued release of hot radioactive gases until the BLOB has diluted itself, or will they continue for a generation or so?

 

[jlduh]

Hi, back again after more than 2 weeks without internet, try to sum up the informations i missed in between.

Sorry if this has been already posted but I wanted to mention that this page on the messy Tepco website has a bunch of videos and pictures that they released, you have to download them sometimes which is not very friendly but anyway, i think there may be some interesting material to analyze.

http://www.tepco.co.jp/en/news/110311/index-e.html

I let you go through the material there, some was not available before I left beginning of April.

I put this interesting picture of the level of water at the plant during the tsunami, very impressive:

http://www.tepco.co.jp/en/news/110311/images/110412_2f_tsunami_6.jpg

The same point without the tsunami water:
http://www.tepco.co.jp/en/news/110311/images/110422_2f_tsunami_7.jpgOf interest also this part of the page with videos from remote T Hawk helicopter (17 April)
Movies taken from T-Hawk, Reactor Building, Unit 1, 3,4 Fukushima Daiichi Nuclear Power Station

Unit 1 ,3,4(1/3)
(Video on April 15, 2011)
http://www.tepco.co.jp/en/news/110311/images/110415_1f_1.zip

Unit 1 ,3,4(2/3)
(Video on April 15, 2011)
http://www.tepco.co.jp/en/news/110311/images/110415_1f_2.zipUnit 1 ,3,4(3/3)
(Video on April 15, 2011)
http://www.tepco.co.jp/en/news/110311/images/110415_1f_3.zip

 

[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.

Also, @Astronuc: were you making reference to hydrogen peroxide in post: https://www.physicsforums.com/showpost.php?p=3217855&postcount=1968 in response to my earlier inquiry?

I'm wondering if someone can either help put this line on inquiry to bed, or point me in the right direction for additional research.

 

[rowmag]

I put this interesting picture of the level of water at the plant during the tsunami, very impressive:

http://www.tepco.co.jp/en/news/110311/images/110412_2f_tsunami_6.jpg

The same point without the tsunami water:
http://www.tepco.co.jp/en/news/110311/images/110422_2f_tsunami_7.jpg

Note that these are pictures taken at Fukushima Daini power plant, not Daiichi. Daini is 10 km south of Daiichi, and has achieved stable cold shutdown at all their reactors.

Pretty impressive, though, agreed.

 

[Samy24]

That is amazing! Something so very obvious as the data from Reactor Two and nobody appears to understand what is happening.

Reactor Two is at Atmospheric pressure. Reactor Two has tons of water being poured into it. Reactor Two is NOT venting steam.

In fact the top of the reactor is considerably higher than the temperature of steam. Steam can only go to a higher temperature if it is under pressure, which it is not in this case. Reactor two is venting hot radioactive gases.

So,I ask my question in the morning that I asked at night. Does anybody have any theories as to how the water is missing the core which has to be out of containment at this time. Are we going to see a continued release of hot radioactive gases until the BLOB has diluted itself, or will they continue for a generation or so?

Maybe Fred (and I) want to know where you have picked this: "Reactor Two is NOT venting steam"

 

[Joe Neubarth]

Maybe Fred (and I) want to know where you have picked this: "Reactor Two is NOT venting steam"

Have you seen any hot billowing clouds out of Reactor Two in the past week? Note that the temperature at the top of the reactor is above that of steam.

 

[Dmytry]

That is amazing! Something so very obvious as the data from Reactor Two and nobody appears to understand what is happening.

Reactor Two is at Atmospheric pressure. Reactor Two has tons of water being poured into it. Reactor Two is NOT venting steam.

In fact the top of the reactor is considerably higher than the temperature of steam. Steam can only go to a higher temperature if it is under pressure, which it is not in this case. Reactor two is venting hot radioactive gases.

So,I ask my question in the morning that I asked at night. Does anybody have any theories as to how the water is missing the core which has to be out of containment at this time. Are we going to see a continued release of hot radioactive gases until the BLOB has diluted itself, or will they continue for a generation or so?

spotted it myself ages ago, it was also the case for #1 that steam was hotter than it could be if the fuel is covered (and it was under pressure).
http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/plot-un1-full.png

http://www.engineeringtoolbox.com/saturated-steam-properties-d_457.html

Actually, steam can be at higher temperature when it is not under pressure. What it can't do, it can't get to a higher temperature without being heated by something hotter still, that is not covered by water. Water cannot be at higher temperature if it is not under pressure.

 

[rowmag]

Rowmag and Tcups, can I please take a moment to say THANK YOU! Thank you for these two absolutely pure rational logical conclusions. This thread is becoming so wildly speculative, I am almost amazed people haven't come out and said these explosions were an inside job...

Don't know about you, TCups, but I have been called many things, but rational/logical is not one of them. A first!

 

[Samy24]

Have you seen any hot billowing clouds out of Reactor Two in the past week? Note that the temperature at the top of the reactor is above that of steam.

At the TEPCO (lowres) webcam I can not see any steam since the last two days
http://www.gyldengrisgaard.dk/tepcowebcam/tepweb20110420.html"

So does that mean that reactor 1-3 and all the SFP's are run dry?

 

[clancy688]

So does that mean that reactor 1-3 and all the SFP's are run dry?

Or they are sufficiently cooled -> water isn't boiling, no steam

 

[Jorge Stolfi]

So, no surprise, we see steam coming from that area...But soon that steam dissipated. .

Also remember that the SkyGlobe pic is taken from orbit, so it will include any clouds that happened to be between the plant and the satellite, even in the statosphere. Not so for wbcam and airplane pics.

 

[jlduh]

Originally Posted by jlduh
I put this interesting picture of the level of water at the plant during the tsunami, very impressive:

http://www.tepco.co.jp/en/news/11031..._tsunami_6.jpg

The same point without the tsunami water:
http://www.tepco.co.jp/en/news/11031..._tsunami_7.jpgNote that these are pictures taken at Fukushima Daini power plant, not Daiichi. Daini is 10 km south of Daiichi, and has achieved stable cold shutdown at all their reactors.

Pretty impressive, though, agreed.

Sorry, i didn't give this precision but you are right, this is Daini. But really we didn't talked a lot about this second plant as it achieved cold shutdown but looking at this picture anyone can see that we've been pretty close to a second disaster! I will be interested to see what can explain the difference concerning the consequences between the two plants: technical differences (positionning of the diesel generators?) or... luck?

After the fact, that's really a scary picture to me.

 

[Samy24]

Or they are sufficiently cooled -> water isn't boiling, no steam

That was the thing I want to point at. But this would mean that TEPCO reports wrong data readings or the instruments are all gone crap.

 

[clancy688]

I will be interested to see what can explain the difference concerning the consequences between the two plants: technical differences (positionning of the diesel generators?) or... luck?

I think, Daiichi 1-4 are at 10 metres elevation. 5-6 and Daini 1-4 are at 14 or 15 metres elevation.

The tsunami had a height of 14-15 metres. So there's your explanation.

 

[jlduh]

Can somebody explain me how to interpret the fact that since several weeks know, i see written in the reports (Tepco, AIEA) that the fuel rods are around half length uncovered -so outside of water- in reactors 1 to 3?

I mean, do i have to understand that:

1) they are still "uncovered" half length,
or
2) that they have melted this length and possibly relocate at the bottom, in the water?

If 1), how can they be uncovered and still not melted?

Thanks for your precisions on that.

 

[clancy688]

If 1), how can they be uncovered and still not melted?

Thanks for your precisions on that.

You missed 3) sensor malfunction.

 

[elektrownik]

Who want explain why core temperature (empty core as tepco say) is 11C bigger than SFP ?
http://www.mod.go.jp/j/approach/defense/saigai/tohokuoki/kanren/230420.pdf

 

[jlduh]

clancy 688: that may be A difference (I have to confirm your elevation data) but still, the picture i posted shows that there has also been a heavy flooding of the platform at the Daini plant (which i didn't really know about to tell you the truth). At the Daichi plant, if i remember well, the diesel generators were at ground level (or even below ground level maybe, in the basement of the turbine building? Don't remember...). So my point is: ok the tsunami has been worse at Daichi than at daini because some difference of height of the platform but still, did the EDG at Daini went under water, or close to go under water too?

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110409e9.pdf

 

[default.user]

Once again in german:

1.Mit welcher Sicherheit kann man eine neuerliche Kritikalität ausschließen?

http://www.gyldengrisgaard.dk/tepcowebcam/20110417190100.jpg

Es gibt viele solcher Bilder. Das Bild vom 15.04.2011 - 19:00 Uhr ist nicht auffindbar.

2.Kann man eine Kernschmelze ohne Problem mit Wasser kühlen?
3.Welche Umstände führen zu einer Wasserdampfexplosion?

Vielen Dank

 

[clancy688]

ok the tsunami has been worse at Daichi than at daini because some difference of height of the platform but still, did the EDG at Daini went under water, or close to go under water too?

I have currently no sources (I'm in class right now), but as far as I remember, Daichi 1-4 have been flooded 5 metres deep and Daiichi 5-6 and Daini 1-4 only 1 metre deep.

 

[Joe Neubarth]

I think, Daiichi 1-4 are at 10 metres elevation. 5-6 and Daini 1-4 are at 14 or 15 metres elevation.

The tsunami had a height of 14-15 metres. So there's your explanation.

To be precise, the tsunami was only about four meters. The run up from the tsunami reaching land was in excess of 14 meters.

San Onofre in San Diego County is not designed to withstand a run up in excess of 9 meters, which can be caused by a tsunami half that height. And yet, San Onofre is still allowed to operate with over 3 million people living within 50 miles of the site.