Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[razzz]

You seem to be referring to a layer of ribbed sheet metal (aluminum?) strips that sits over the steel framework. Those strips look like bits of white fettucini in the aerial photos (some 8 meters long and less than 1 meter wide), and are scattered all over the place. a few of them are still attached to the steel frame of #4.

Above that sheet metal layer there seems to be a dark grey layer of concrete and/or tarmac. In the best photos of #4 one can see some ribbing on it too, possibly a negative cast of the ribbing on the metal sheets. That layer presumably is reinforced with rebar or wire mesh, because in #4 a chunk some 15-20 meters across was thrown up in the air, then sliced though the steel beams next to the north wall, and is still hanging there in one piece.

In #4 the entire concrete/tamac layer and almost all the metal sheets of the roof were blasted away. Part of the explosion indeed appears to have occurred in the 4th floor (below the service floor), but the only communications between those floors are the elevator shaft and four narrow stairwells at the corners. That is quite enough for the H2 to flow between floors, but hardly enough to transmit the explosion with such a force. Moreover the service floor slab of #4 does not appear to have been breached or even cracked (unlike that of #3).

I still cannot quite understand what hapened to the top of the north wall of #4. Its exterior paint seems to have been scraped down, and its top edge was pushed southwards (i.e. inwards) by several meters. I thought about the middle parts of the pillars being pushed out by the explosion and causing the tops to pivot inwards; but there does not seem to be anything in that location that could have served as the pivot, and I cannot see how the explosion could have pushed the middle of the pillars out without also pushing the top...

I use Nero 8 for video viewing which has a 'digital zoom' feature to outline an area to enlarge it (to the point of over pixelization). When I do that on the parapet wall closest to the camera of Unit 3 and include part of the roof before the explosion, I see the building breathing in and out. Since it hasn't exploded as of yet, I considered it to be steam releasing inside and condensing along with the pre-loading of other gases. Over pressure finally causes separation of the roof followed by a chain reaction.

Unit 4 doesn't seem to be afforded the pre-loading whereas the blast(s?) came first then the pressure, leaving everything just bent in one position with a kinda random destruction about the building. I don't think the remaining roof section ever got airborne as pointed out by a onetime poster/engineer/architect, just was moved by the wall pushing in.

I really doubt the use of aluminum for the roof panel sections, more like galvanized steel (zinc plating). I always thought Units 2,3 and 4 had a bit of over designed skinning but it is hard to reach a happy medium between earthquake and wind loads while engineering to release an internal explosion.

And while I'm thinking about it, the Unit 3 SFP video where just before the camera goes underwater, it shows the outside of the tank. The tank appears heavily painted or has a coating of some sort that appears to have bubbled due to heat.

Let me qualify all this with... what the hell do I know?

 

[havemercy]

Sorry for interrupting, but I have just one question. If the water leaks outside the structure, why they just stop putting tons of water inside ? Would the situation become really worst if they stop ? Thanks in advance for reply.

 

[etudiant]

Sorry for interrupting, but I have just one question. If the water leaks outside the structure, why they just stop putting tons of water inside ? Would the situation become really worst if they stop ? Thanks in advance for reply.

Nobody knows for sure, but the reactors have not melted into piles of slag as far as we can tell.
Left entirely without cooling, they would. So the water injection is continued, because it may be helping.
This is why the US NRC head described the situation as 'static' rather than 'stable'.
It may be that the situation is at the threshold of a greater disaster if some incorrect action is taken or if something else in the site breaks, perhaps because of an aftershock.
TEPCO is certainly using a kid gloves approach, touching as little as possible and planning for a year long campaign to get to a cold shutdown, before a decades long cleanup.
Others, notably Michio Ishikawa, the former head of the Japan Nuclear Technology Institute, vehemently disagree with this approach and propose much more vigorous efforts, because the situation is worsening on the current course. See: http://www.gengikyo.jp/english/shokai/Tohoku_Jishin/article_20110413.htm

 

[triumph61]

#Fukushima I Nuke Plant Reactor 1 Bldg: 2,000 Millisieverts/Hr at Southeast Double Door, 3,000 Tons of Water in the Basement

1,000 millisieverts/hour on the 2nd floor was bad enough. And this was supposed to be the reactor that was well on its way to stable cold shutdown.

http://ex-skf.blogspot.com/

 

[MadderDoc]

New photo (taken May 13th) released by Tepco
http://www.tepco.co.jp/en/news/110311/images/110514_5.jpg

 

[StrangeBeauty]

Worker dies at #1 -- the cause is not clear

- At about 6:50 AM on May14th, 2011, a worker of a sub-contractor became a
bad health during a carrying work for drainage treatment system in the
Centralized Environment Facility. He was carried to hospital.
Radioactive substances were not attached to the worker.

http://www.tepco.co.jp/en/press/corp-com/release/11051410-e.html

Opinion about that photo from MadderDoc -- hard to believe that any part of #4 looks like that. Might it be #5 or #6?

Also from the same release above:

- From 1:00 pm to 2:37 pm on May 14th, we sprayed water into the spent fuel
pool of Unit 2 using the temporary motor driven pump. (from 1:08 pm to
2:02 pm, hydrazine was also injected).

Also radioactive density counts on the way up at #1 sub-drain:

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110514e10.pdf

2 Sv/hr readings in #1 are not encouraging imo.

 

[Caniche]

New photo (taken May 13th) released by Tepco
http://www.tepco.co.jp/en/news/110311/images/110514_5.jpg

7000 tons ?:rofl:

 

[triumph61]

New photo (taken May 13th) released by Tepco
http://www.tepco.co.jp/en/news/110311/images/110514_5.jpg

May 13th.
Please refer to "[Reference] Emergency Response Training at Fukushima Daini Nuclear Power Station" for the explanation of each picture.
http://www.tepco.co.jp/en/news/110311/index-e.html

 

[SteveElbows]

New photo (taken May 13th) released by Tepco
http://www.tepco.co.jp/en/news/110311/images/110514_5.jpg

Note that this is from emergency training exercises being carried out at the Daini plant, as detailed here:

http://www.tepco.co.jp/en/news/110311/images/110514_11e.pdf

edit - Oops sorry triumph61 beat me to it.

 

[PietKuip]

New photo (taken May 13th) released by Tepco
http://www.tepco.co.jp/en/news/110311/images/110514_5.jpg

Why on Earth are they aerosolising the water with that shower head?

 

[MadderDoc]

I use Nero 8 for video viewing which has a 'digital zoom' feature to outline an area to enlarge it (to the point of over pixelization). When I do that on the parapet wall closest to the camera of Unit 3 and include part of the roof before the explosion, I see the building breathing in and out.
<..>

That's a nifty feature of Nero 8. Can you using this same method check whether you can see the same phenomenon looking at unit 2 and/or unit 4?

And while I'm thinking about it, the Unit 3 SFP video where just before the camera goes underwater, it shows the outside of the tank. The tank appears heavily painted or has a coating of some sort that appears to have bubbled due to heat.

I would very much like to see what it is you are looking at. There appears to be some metal structures or edges hanging out in the pool at shallow depth (They stand out by being large generally frame-spanningly,, blocking the view to the bottom and being rather less green than the rest we see, rather they are white/grey patched and reddish at the edges. There is a peculiar hook like shape of one of them, it looks like we see on its edge that it is concrete lined with thick metal My best idea so far is that we are looking at parts of the steel liner of the pool. If so, it looks rather more twisted and bent than I had imagined it to be, but curiously it does do not seem to have been hit by anything mechanical, no scratch marks or bumps.

Let me qualify all this with... what the hell do I know?

But you know that you have fun doing this, eh? :-)

 

[Samy24]

Why on Earth are they aerosolising the water with that shower head?

It's just a joke. That is not real!

 

[PietKuip]

It's just a joke. That is not real!

Everything for the camera: the bunny suits, the gas masks, and the photographer wants to see some water please.

 

[MadderDoc]

Note that this is from emergency training exercises being carried out at the Daini plant, as detailed here:

http://www.tepco.co.jp/en/news/110311/images/110514_11e.pdf

edit - Oops sorry triumph61 beat me to it.

I was hoping for someone to say something like this, frankly the photo had me quite confused, I had overlooked the footnote. Thanks.

 

[Samy24]

Everything for the camera: the bunny suits, the gas masks, and the photographer wants to see some water please.

It's a paddling pool for their children filled by a garden hose.

Sorry for that not really technical response.

 

[~kujala~]

English version says 3000 tons of water missing, Japanese version says 3000 tons of water found in basement.

So what now? Fill the basement with cement?

They have to find ways to transfer water from the basement of the reactor buildings to storage facilities. It's difficult but perhaps not impossible? And even if it's not going to succeed they still have the sub-drain systems.

Regarding the ground water: we have to separate two things, the sub-drain system and the water below the sub-drain system.

The water in the sub-drain system is collected to the sub-drain pits and from there it is pumped to a storage facility and from there it is transferred to the sea (in normal operation mode, because the water is clean, no harm done here). This is a way to control the movements/levels of the ground water underneath the reactors.

So the sub-drain system to some extent takes care of the polluted water underneath the plants. This is what they have already done in units #5 and #6, they pumped the water up from the pits and transferred it to the sea. The water was low-level contaminated so TEPCO thought it was safe to transfer it to the sea.

As for the units #1 - #4, the groundwater is more polluted. So the problem arises: How much water has accumulated in the sub-drain pits? What is TEPCO going to do with that water? As long as the sub-drain system is still working OK, we can assume that the contamination of the ground water is still "under control".

In one of the papers TEPCO gave us a small hint what they are going to do with the sub-drain water underneath #1 - #4:

Treatment of sub-drainage water after being pumped up

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f12np-gaiyou_e.pdf
(page 22)

But they have not given us any schedule, have they? This is one answer I am waiting from TEPCO, to give more detailed report of the sub-drains #1 - #4, their thoughts about where the polluted water has been coming and when they are going to empty the pits.

But there is also a more severe problem if some polluted water goes underneath the sub-drain systems. Some reasons leading to this might be: 1) The sub-drain systems do not cover the whole area of the plant. 2) The sub-drain systems might not work everywhere as supposed because of the tsunami/quake.

Underneath the sub-drain systems there is only the moving ground water, it's not under control. But even this situation is not necessarily a catastrophe. Because the inland deep well is not contaminated it gives us a hint that the ground water is moving towards the sea. This is also how it is usually supposed to work nea the sea, and the findings from the deep well support this scenario.

What would happen? The pollution in the ground water would dilute little by little into the sea probably not causing any dramatic rise in the radiation levels of the sea water. This is also what the overall trend has been after they were able to stop the mega-leak from the unit #2 pit to the sea: the radiation levels have been decreasing.

So what would actually happen, is this: the nature would take care of some of the cleaning processes of the Fukushima plant - even without TEPCO asking for it.

 

[etudiant]

They have to find ways to transfer water from the basement of the reactor buildings to storage facilities. It's difficult but perhaps not impossible? And even if it's not going to succeed they still have the sub-drain systems.

Regarding the ground water: we have to separate two things, the sub-drain system and the water below the sub-drain system.

The water in the sub-drain system is collected to the sub-drain pits and from there it is pumped to a storage facility and from there it is transferred to the sea (in normal operation mode, because the water is clean, no harm done here). This is a way to control the movements/levels of the ground water underneath the reactors.

So the sub-drain system to some extent takes care of the polluted water underneath the plants. This is what they have already done in units #5 and #6, they pumped the water up from the pits and transferred it to the sea. The water was low-level contaminated so TEPCO thought it was safe to transfer it to the sea.

As for the units #1 - #4, the groundwater is more polluted. So the problem arises: How much water has accumulated in the sub-drain pits? What is TEPCO going to do with that water? As long as the sub-drain system is still working OK, we can assume that the contamination of the ground water is still "under control".

In one of the papers TEPCO gave us a small hint what they are going to do with the sub-drain water underneath #1 - #4:

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f12np-gaiyou_e.pdf
(page 22)

But they have not given us any schedule, have they? This is one answer I am waiting from TEPCO, to give more detailed report of the sub-drains #1 - #4, their thoughts about where the polluted water has been coming and when they are going to empty the pits.

But there is also a more severe problem if some polluted water goes underneath the sub-drain systems. Some reasons leading to this might be: 1) The sub-drain systems do not cover the whole area of the plant. 2) The sub-drain systems might not work everywhere as supposed because of the tsunami/quake.

Underneath the sub-drain systems there is only the moving ground water, it's not under control. But even this situation is not necessarily a catastrophe. Because the inland deep well is not contaminated it gives us a hint that the ground water is moving towards the sea. This is also how it is usually supposed to work nea the sea, and the findings from the deep well support this scenario.

What would happen? The pollution in the ground water would dilute little by little into the sea probably not causing any dramatic rise in the radiation levels of the sea water. This is also what the overall trend has been after they were able to stop the mega-leak from the unit #2 pit to the sea: the radiation levels have been decreasing.

So what would actually happen, is this: the nature would take care of some of the cleaning processes of the Fukushima plant - even without TEPCO asking for it.

Perceptive assessment, provided people realize that nature's cleanup cycle might be a lot slower than we would like. Seems the Fukushima Wildlife Refuge is well on its way to being realized, albeit contaminated both above and below ground.

 

[liamdavis]

From P418, sorry to be so far behind!

I agree that the industry has generally been underestimating the hazards from spent fuel pools, although at least the US appears to have taken some action to ensure means are readily available to add water. You can be sure that there will be industry wide changes to spent fuel pools and emergency cooling etc. The addition of simple spray headers above the pools has been discussed.

However, none of this matters if plants are not adequately designed for Beyond Design Basis Events (BDBE). All of this destruction and pool overheating was caused by all emergency power being lost to the units by a BDB tsunami event that flooded the emergency generators and switchgear that was located in the lower floor of the non-watertight turbine building.
The provision of readily available "ultimate" emergency power equipment will be the most significant change for the industry. One simply cannot tolerate (or afford) having no power to cool a nuclear reactor.

The industry is responding behind the scenes all around the world and addressing current emergency readiness and addressing the initial lessons-learned from Dai-ichi. Many more lessons-learned to come - just like what happened after TMI and Chernobyl.

I am a little less concerned with the plants being designed for Beyond Design Basis Events because of the amount of time it will take to deal with that. The planned response to Beyond Design Basis Events can be modified in a much shorter time period. As this thread basically discusses the results of an inadequate response to Beyond Design Basis Events does anyone have any information on changes to planned response to such events?

In order not to derail his thread you may respond here.
liam https://www.physicsforums.com/showthread.php?t=487336

 

[razzz]

Using http://www.youtube.com/watch?v=UPQv7DF4q94" press pause or the space bar then put the mouse on the slider button to look at single frames (can't go step by step). Loading 'Download Helper' (a FireFox add-on) works well as it lists all the possible video media formats when available for download ex. flv, mp4 (found in Tools>DownloadHelper>Media).

If you just press and hold the 'Ctrl' and move the wheel button on your mouse, you can enlarge or reduce the screen. Good for a text reading or a quick pic enlargement.

Attached is a still .jpg along with an enlarged section captured of the roof corner of Unit 4 and Unit 3 closeup capture from the SFP video showing whatever it is: metal debris with paint or coating. Good high quality pics or video, gets you better quality captures or enlargements.

 

[imandylite]

New Kimono design to cover Fukushima embarrassment.

For Reactor Unit 1 - hopefully by end May 2011

[PLAIN]http://img263.imageshack.us/img263/5262/11051302.jpg

Report

https://www.youtube.com/watch?v=9Xi8c_UgB58

http://www3.nhk.or.jp/daily/english/14_02.html"

From what I remember of the details (which I can't find now) it was a heavy duty polyester rip stop fabric over a lightweight steel frame.

 

[Gary7]

First time poster. Lurker of just the past few days. Apologies in advance if I run aground of the rules. I am not a physicist. I am a long-time resident of Tokyo. I speak and read Japanese. Many, many thanks to the contributors of this site, and to the moderators, as there are very few sites with as many knowledgeable comments as I have found at PhysicsForums. I have been following the Fairewinds site for some time and am generally impressed, but I was disappointed when they picked up started promoting the "Reactor #4 is Leaning" story that has been circulating around the blogosphere. I am still trying to understand the possibilities of recriticality and so I am quite interested in the discussions I have read here. Having said that, I have only one thing to add to the discussion this morning, and that is the radiation readings from inside reactor unit #1. This comes from today's Tokyo Shimbun. For those who are familiar with BWR Mark 1, it may help decipher which part of the RPV or drywell that is leaking. The translations are mine. The original is at the site below. The view is from the top, looking down at the reactor building (RPV is the circle in the center).
http://www.tokyo-np.co.jp/article/national/news/CK2011051502000040.html

 

[westfield]

snip >What you wrote about mono/stereo is interesting. I guess plotting the difference between L/R channels should show that's really the case - I would expect it to be flat for mono and not-flat for stereo (plus minus compression artifacts).

Indeed, I considered summing the channels , both in and out of phase to investigate further but the samples make it so obviously wrong I didn't bother delving into it any deeper.

Personally I despise how news services dramatise the news nowadays with video and audio special fx amongst other techniques. Bad news doesn't need to be made to appear worse just for ratings.

 

[AntonL]

So, the reactors may not have survived the initial earthquake!

Data taken at the Fukushima Daiichi nuclear power plant on the night of March 11 showing a high level of radiation at a reactor building suggest the possibility that key facilities there may have been damaged by the quake itself that day rather than tsunami-caused power loss that failed the reactor's cooling function, a utility source said Saturday.

complete article here: http://english.kyodonews.jp/news/2011/05/91126.html

"a utility source said Saturday" is this a further Tepco leak but of a kind we need.

 

[AntonL]

Tokyo Electric Rules Out Future Criticality at No. 1 Reactor

Is there any scientific evidence to support above statement?
http://jen.jiji.com/jc/eng?g=eco&k=2011051400003

 

[default.user]

Tokyo Electric Rules Out Future Criticality at No. 1 Reactor

Is there any scientific evidence to support above statement?
http://jen.jiji.com/jc/eng?g=eco&k=2011051400003

It was already reported in March that Technicium99m was found.
In one German media is thus based on criticality.
Often the argument of the rapidly declining decay heat is given. Normally, should have reassured the nuclei after two months of cooling.
Nevertheless, the temperature in the reactors.
For me, the rise in temperature is an indication of criticality and thus increasing or constant temperature, despite cooling.
Perhaps the corium has formed a skin. The corium is washed with water from the outside. The boron in the water can not flush the corium. Thus its effect is irrelevant.

Sorry my bad english.

Kind regards

http://www.taz.de/1/archiv/print-ar...sort=sw&dig=2011/03/29/a0082&cHash=96559c9d6c

 

[AntonL]

They injecting 14,5m³/h to unit 3 now but temperatures going up not down...

In April water injection was a steady 6m3
4 May increased to 9m³ in response to rising temperature
13 May increased 60 12m³
14 May increased to 15,5m³

However no rise in water level, actually a fall in the last couple of days if water level meters can be trusted after Unit 1 experience. More worrying, is that temperatures in the bottom of reactor are not coming down, I suspect we have the same situation as in Unit 1 but a bit more serious due to the higher temperatures in lower reactor that are not coming down. (2-brown and 4-red as bold lines)

The RPV top body flange (3) and stud bolt (5) temperature sensors are up and down like a yo-yo. However, other temperatures have suddenly shown a steady dramatic rising trend.

I am waiting for the Tepco announcements regarding the state of Unit 3, I think that the core is also in the bottom of the reactor and in a more serious state and Tepco is much concerned as they are injecting huge volumes of water, with no apparent effect, which will be a near-future and costly disposal problem for them. Also they doubled their logging rate, http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05150600.pdf

[PLAIN]http://k.min.us/in6LVe.JPG
http://i.min.us/ilcM2M.jpg"

 

[MiceAndMen]

Personally I despise how news services dramatise the news nowadays with video and audio special fx amongst other techniques. Bad news doesn't need to be made to appear worse just for ratings.

Can someone please refresh my memory and say who first posted the Unit 3 boom-boom-boom explosion video? Was it a news network or some random youtube user? I have a very short list of "news media" outlets that I do not trust based on verifiable failures to report the news accurately. I would like to know if that list needs updating. At one time I respected the journalistic profession but those days are long gone (starting around the time Rupert Murdoch arrived on the scene).

Who was responsible for the Youtube posting (that first included the bogus soundtrack) of the explosion at unit 3?

 

[AntonL]

http://www3.nhk.or.jp/daily/english/15_04.html

The company had planned to fill the containment vessel with water and set up a cooling system. But it now says that it will study a plan to circulate water directly from the basement, through a decontamination filter and heat exchanger, and then back into the reactor.

Will this also be the solution for units 2 and 3?

 

[razzz]

Can someone please refresh my memory and say who first posted the Unit 3 boom-boom-boom explosion video? Was it a news network or some random youtube user? I have a very short list of "news media" outlets that I do not trust based on verifiable failures to report the news accurately. I would like to know if that list needs updating. At one time I respected the journalistic profession but those days are long gone (starting around the time Rupert Murdoch arrived on the scene).

Who was responsible for the Youtube posting (that first included the bogus soundtrack) of the explosion at unit 3?

I linked to a video with the audio imbedded, don't know if I was the first. Not sure where I found it when chasing links at the time but clicking on the below link has notations on the video attributing to where it came from, not sure if it is correct or not.

http://sinais2012.blogspot.com/2011/03/fukushima-i-nuclear-power-plant-reactor.html"

I downloaded the video and if you paste the name in a search engine box it will turn up everywhere as a lot of sites used it. Can't say if it was the original name or not.

Fukushima I Nuclear Power Plant Reactor 3 explosion on March

Attached is the Information imbedded in the video.

In the beginning I was more interested in the redness coloring of the plume clouds and noted the audio was out of sync and later posted I couldn't confirm the audio track belonged to the video after posters were skeptical of the sound track as it was shown without audio when first aired, at least that what some comments said about the video. I thought it might be the correct sound but not that important.

 

[elektrownik]

http://www3.nhk.or.jp/daily/english/15_04.html


Will this also be the solution for units 2 and 3?

No ? In unit 1 they inject 10 000 t of water, but they found only 3000 t, so this mean that water is leaking from reactor building... it would be great solution, but with leaks not, (unit 2 is also leaking).

 

[liamdavis]

With respect to the unit 3 reactor pressure vessel. If water were below the fuel, and a significant quantity of corium dropped into it, the volume of steam generated could exceed the capacity of the relief valves and leaks to discharge it. On a graph, a sharp high spike over a short time span would represent this. While this inadequate pressure venting was taking place more water would be able to super heat under the increasing pressure. When catastrophic failure finally occurred water would flash to steam. Modern boilers rarely explode not just because of relief valves but because the controls remove the heat being applied and thus the volume of steam to be vented. That could not be done in this case.

Grist for the mill.
liam

 

[AntonL]

No ? In unit 1 they inject 10 000 t of water, but they found only 3000 t, so this mean that water is leaking from reactor building... it would be great solution, but with leaks not, (unit 2 is also leaking).

No other way round they can account 7000 in PCV and 3000T missing, assumed in the basement and partly leaked to environment.

Basement Half Filled with Water http://jen.jiji.com/jc/eng?g=eco&k=2011051400367

Tokyo Electric Power Co. found Saturday that the basement of a reactor building at its crippled Fukushima No. 1 nuclear power station is half filled with radioactive water. The radioactive water at the plant's No. 1 reactor is likely to have leaked from the containment vessel to the basement of the building that houses the vessel, the plant operator said

However, by reducing basement water level, leakage to environment is reduced.

And I take any bet that 3 is leaking too!

 

[westfield]

Can someone please refresh my memory and say who first posted the Unit 3 boom-boom-boom explosion video? Was it a news network or some random youtube user? I have a very short list of "news media" outlets that I do not trust based on verifiable failures to report the news accurately. I would like to know if that list needs updating. At one time I respected the journalistic profession but those days are long gone (starting around the time Rupert Murdoch arrived on the scene).

Who was responsible for the Youtube posting (that first included the bogus soundtrack) of the explosion at unit 3?

I doubt there is a version of the video with the soundtrack in question that doesn't include a SKY or Channel 9 (Australia) watermark. It sounds more like a SKY presenter. Both love to tart the news up.
But who knows where it originated, this is at least a direct copy of the original, if not the source -

http://video.au.msn.com/watch/video/9raw-hydrogen-explosion-at-nuclear-plant/xy3zbug"
(you may have to sit through an advert unfortunately)

Then here on youtube with the Ch 9 watermark again. (wow, over 2 million views of that clip)
http://www.youtube.com/watch?v=T_N-wNFSGyQ"

NTV who apparently took the footage seem only to show it with a big graphic over the explosion, wt? - http://www.youtube.com/watch?v=vMCa-Zo_ZEU"

 

[PietKuip]

Tokyo Electric Rules Out Future Criticality at No. 1 Reactor

Is there any scientific evidence to support above statement?
http://jen.jiji.com/jc/eng?g=eco&k=2011051400003

This quote is certainly true:

"A lack of water makes it more difficult for criticality, or a self-sustained nuclear fission chain reaction, to happen, the officials said."

 

[zapperzero]

So, the reactors may not have survived the initial earthquake!
complete article here: http://english.kyodonews.jp/news/2011/05/91126.html
"a utility source said Saturday" is this a further Tepco leak but of a kind we need.

I hate being right about this kind of thing. I'm betting on the RHR. Any takers?