Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[swl]

FYI 6.2 quake not that far away (but 37.6 km (23.4 miles) deep).

http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0003etn.php#details

Should give things a least a bit of jiggle there.

It was rated at Magnitude 5.7 and Shindo 4 near the plant.

200 kilometers south of the plant, my house and computer desk were shaking audibly but gently.

 

[jlduh]

I would like to see a proper english translation of http://www.asahi.com/special/10005/TKY201105120706.html

By what I can make out it discusses un-published internal reports and documents by TEPCO that asahi claim now to have in their possession, more than 100 pages listing many parameters, trends, work groups etc. These documents reveal that on 13th March high radioactivity in or around Unit 3 were measured and observation of steam with high probability of hydrogen escaping into the building. (Unit 3 exploded on the 14th a day later)

If my interpretation of the machine translation is true, then Tepco have not only leaks in reactors.

Well, in my opinion, Tepco knows much more than us about what happened in their reactors. A probable way through which we will get these infos will be some wikileaks or equivalent distribution...

Don't expect this nuke industry to reveal all critical infos to stupid citizens like us, that's not the common culture in place there. We could be scared, or even angry. Just don't tell em...

But for sure, leaks will come...

 

[rowmag]

It was rated at Magnitude 5.7 and Shindo 4 near the plant.

Shindo 4 shouldn't do much.

 

[etudiant]

Should there not be more recognition of the role of the salt in the reactors?
There were estimates for the volume of salt left behind in the reactors from the emergency cooling, it was appreciable relative to the overall RPV volume.
So is it possible the fuel pellets freed up by the loss of the cladding would not collect at the bottom of the reactor, but rather be caught in the salt, like raisins in a cake. That would prevent the fuel from coalescing and overheating, which might explain the low temperature at the bottom of reactor 1.
Is this a plausible possibility or is there some obvious fact that makes this an invalid idea?

 

[razzz]

When unit #4 exploded, most of the roof's concrete (or some similar material) was apparently lifted as a unit, and then fell at an angle into the roof steelwork near the north wall. Part of it is still sticking out of the roof. The part that is below the roof can be glimpsed in this photo

http://www.flickr.com/photos/xtcbz/5705937712/in/set-72157626687253144

It is the dark grey "drape" in the background. As others have observed, the "groves" or "folds" visible on that thing are probably the impressions of metal roof panels that supported it.

Seems possible that some of the large objects that were lifted by the explosion of #3 may have been similar to this sheet.

These roof panels that are long and narrow and overlapping or interlocking when attached to the joists and ribbing that make up the roof appear to my eye to be made to scatter to relieve pressure whether there is lightweight concrete poured over them then roofing material applied or some other type of roofing (system) to complete the roof.

Unit 4 looks like the blast (type??) came from the lower floors so didn't disengage the entire roof like a 'normal' hydrogen explosion would and even forced the parapet and its associated pivoting wall inward during the blast just pushing or sliding the roof section that remained inward until it folded the framework. Either that or the forces at work are/were pulling down on a weaken structure i.e. pool's dead weight...I don't know and neither do they.

 

[NUCENG]

I'd rather not speculate what they mean by the singular 'basement', but I have seen Tepco use the expression 'second basement floor' in some of their releases relating to unit 1. This would imply that in the eyes of Tepco there is in that reactor building at least two basement floors.

The ground level floor is the area where the scram headers are located. Below ground level is the torus room and corner rooms where RHR and Core Spray system pumps are located. In BWR4s the HPCI and RCIC systems may also be on this level. There is a mezzanine level in the corner rooms that may be what is being referenced.

 

[jim hardy]

Rowmag

that timespan you mention is interesting .. there was something going on not long after they started seawater injection but I've never been able to tie times together.

There's this article, probably you guys saw it too but for refresher:

"""Neutron beam observed 13 times at crippled Fukushima nuke plant

TOKYO, March 23, Kyodo

Tokyo Electric Power Co. said Wednesday it has observed a neutron beam, a kind of radioactive ray, 13 times on the premises of the Fukushima Daiichi nuclear plant after it was crippled by the massive March 11 quake-tsunami disaster.

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant's No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level.

The utility firm said it will measure uranium and plutonium, which could emit a neutron beam, as well.

In the 1999 criticality accident at a nuclear fuel processing plant run by JCO Co. in Tokaimura, Ibaraki Prefecture, uranium broke apart continually in nuclear fission, causing a massive amount of neutron beams.

In the latest case at the Fukushima Daiichi nuclear plant, such a criticality accident has yet to happen.

But the measured neutron beam may be evidence that uranium and plutonium leaked from the plant's nuclear reactors and spent nuclear fuels have discharged a small amount of neutron beams through nuclear fission.

==Kyodo""

http://english.kyodonews.jp/news/2011/03/80539.html

We got somebody to translate from Japanese newspaper and "beam" meant slight radiation as in miniscule rays, not intense beam as in a searchlight.

At the time i attributed it to some unlucky plant guy walking around with contaminated shoes and passing by the monitors.
Will stay tuned to your board here.

 

[rowmag]

Should there not be more recognition of the role of the salt in the reactors?
There were estimates for the volume of salt left behind in the reactors from the emergency cooling, it was appreciable relative to the overall RPV volume.
So is it possible the fuel pellets freed up by the loss of the cladding would not collect at the bottom of the reactor, but rather be caught in the salt, like raisins in a cake. That would prevent the fuel from coalescing and overheating, which might explain the low temperature at the bottom of reactor 1.
Is this a plausible possibility or is there some obvious fact that makes this an invalid idea?

The cores were exposed by between 1 m and 1.6 m for 7 hours before they started pumping in borated seawater at 20:45 on the 12th. So a good fraction of the fuel pellets may have fallen to the bottom of the RPV before salt could accumulate. But maybe the later ones could be diluted like that, if the water gauge was correct (for a while -- we know at some point it went bad) and it didn't all go empty right away?

 

[rowmag]

Rowmag

that timespan you mention is interesting .. there was something going on not long after they started seawater injection but I've never been able to tie times together.

There's this article, probably you guys saw it too but for refresher:

http://english.kyodonews.jp/news/2011/03/80539.html

We got somebody to translate from Japanese newspaper and "beam" meant slight radiation as in miniscule rays, not intense beam as in a searchlight.

At the time i attributed it to some unlucky plant guy walking around with contaminated shoes and passing by the monitors.
Will stay tuned to your board here.

Not clear yet what it really was. These are real-time notes or log entries from the height of the crisis, so I doubt TEPCO had much chance to analyze it at the time. Somebody probably just said, "Neutrons? Hmm, better consider the possibility of criticality," and we don't have notes from after that (in the paper, at least) to explain what they may have found out or figured out about it later.

The main thing I find interesting about it is that TEPCO themselves had immediately flagged it as a possibility, which makes me inclined to be a little more forgiving of the folks who later jumped on the bad-translation "neutron beams" phrase to come up with the same idea. Fog of war.

If the rest of those leaked notes get published, perhaps someone can piece it all together.

 

[NUCENG]

Thanks NUCENG. Unfortunately the EPA link is broken.

Keep trying. The documents are public domain. If you still can't get to them PM me and I'll upload them.

 

[razzz]

Should there not be more recognition of the role of the salt in the reactors?
There were estimates for the volume of salt left behind in the reactors from the emergency cooling, it was appreciable relative to the overall RPV volume.
So is it possible the fuel pellets freed up by the loss of the cladding would not collect at the bottom of the reactor, but rather be caught in the salt, like raisins in a cake. That would prevent the fuel from coalescing and overheating, which might explain the low temperature at the bottom of reactor 1.
Is this a plausible possibility or is there some obvious fact that makes this an invalid idea?

A drop of seawater, in trace elements, contains every mineral known to man and high heat just brings the elements out of suspension so I haven't seen any studies on seawater reactions when used as a coolant in nuclear plumbing let alone interactions with nuclear fuels. Maybe the noted glowing was phosphorescence i.e. luminescence of living organisms.

 

[sp2]

Originally Posted by sp2
That was definitely not a function of wind.

Wind was clearly blowing to the SE at that point.

Steam (presumably) was spewing straight out of #3, sideways, toward the north, and then getting blown by the wind out to sea, towards the SE.

I feel that you are ruling out weather phenomenon too definitively here. Failure to take into account a range of weather phenomenon has caused repeated wild speculation over the last week, based on live feed images. There is now a danger that if something really does change, we may miss it because we are so used to these false stories caused by live feed images.

As you can see, people are mostly not too surprised to hear of stuff coming from the north end of the building. Perhaps it would be helpful for you to review a video that was shot early on, and shows an area where this stuff is likely to be coming from:

http://www.youtube.com/user/modchannel

Check out the above at around 3:08, 3:23 and 3:48 for a view of what was escaping from the north side in the past.

Steve--

You seem to have some difficulty with the distinction between 'observation' and 'wild speculation.' My post was an example of the former, and had nothing whatsoever to do with the latter. I very simply reported what I saw, and how it compared with what I had previously seen.
It sounds like many others' observations corroborated mine.

There have indeed been many examples of hyperbole and misinterpretation here.
This was not one of them.

Perhaps it would be helpful for you to review the definitions of those words, before carelessly throwing around labels like 'wild speculation' and 'false stories.'

You have a great weekend.

 

[westfield]

Please search the thread - it is not clear (at least to some) whether the sound is really part of the recording and whether it was not added from some other source.

I'll have a stab at making it clear. Been lurking for a few weeks but this audio discussion has driven me spare and caused me to unlurk.

Take it from a career audio professional and\or look at the evidence below, it's not in any way the sound of unit #3 exploding. To me, a glance at the waveforms is enough to see it's a cut up effects track assembled from a 3 or 4 samples with some tweaks with effects and dynamics.

There are SO many things to speculate about, this audio track shouldn't be one of them. It's fake.

edit : should I have just linked the image or is embeddeding it ok here?

 

[sp2]

I'll have a stab at making it clear. Been lurking for a few weeks but this audio discussion has driven me spare and caused me to unlurk.

Take it from a career audio professional and\or look at the evidence below, it's not in any way the sound of unit #3 exploding. To me, a glance at the waveforms is enough to see it's a cut up effects track assembled from a 3 or 4 samples with some tweaks with effects and dynamics.

There are SO many things to speculate about, this audio track shouldn't be one of them. It's fake.

http://i1185.photobucket.com/albums/z360/fukuwest/misc/fukuu3audiobullgarbage.jpg

edit : should I have just linked the image or is embeddeding it ok here?

Wow. Thanks, that's great stuff.

I have to say, I'm *not* an audio engineer (or anything close to one), but that's what I thought from the first time I heard that tape.

It sounded utterly bogus. Like the same 'boom' repeated three times with the same interval. (Not to mention that it was instantly obvious it had been tampered with to cut out what should've been a very long delay --which called it into question right off the bat.)

I really couldn't understand why intelligent guys seemed to be taking it so seriously, and spending so much time on it.

Thanks for elucidating.

 

[AntonL]

It looks like TEPCO is moving forward with it's plan to cover Unit 1 in a steel frame covered with polyethelene sheets.

to be followed by a concrete structure

[PLAIN]http://k.min.us/inx8Me.JPG

extracted from
http://www.tepco.co.jp/nu/fukushima-np/f1/images/f12np-gaiyou_4.pdf

the English version will become available later today or tomorrow
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f12np-gaiyou_e_4.pdf

this document also discusses the Areva plant (page 12)
and how Unit 2 is proposed to be cooled (pages 3-5)

Earlier and future version of these documents can be viewed by changing the last digit of the file name.

 

[AntonL]

I really couldn't understand why intelligent guys seemed to be taking it so seriously, and spending so much time on it..

intelligent guys will investigate every lead and only stop a particular direction when that direction is proven false.

 

[|Fred]

looking at this
zoom on poor quality video, seem conclusive with the fact that the multiple event "orange explosion and "vertical" movement were closer in there time line that I initially suspected.

I believe I see the birth of "mushroom" cloud sucking in the orange explosion.
There is also some kind of bright effect just behind the tower that is impossible do identity

 

[GJBRKS]

looking at this
zoom on poor quality video, seem conclusive with the fact that the multiple event "orange explosion and "vertical" movement were closer in there time line that I initially suspected.

I believe I see the birth of "mushroom" cloud sucking in the orange explosion.
There is also some kind of bright effect just behind the tower that is impossible do identity

It's getting clear to me that an initial hydrogen burst cracked and depressurized the RPV or containment , followed by the ' emptying' of RPV and/or containment , the 'sucking ' effect produced by the rapid upward movement of gasses

 

[MadderDoc]

The ground level floor is the area where the scram headers are located. Below ground level is the torus room and corner rooms where RHR and Core Spray system pumps are located. In BWR4s the HPCI and RCIC systems may also be on this level. There is a mezzanine level in the corner rooms that may be what is being referenced.

I'd rather not speculate whether that may be the case. Tepco has used the expression 'second basement floor' in connection with the release of a series of photos showing workers standing in full protective gear including boots in a feet of water in what appears to be a long corridor. According to the captions the workers have been photographed in the second basement floor of unit 1.

 

[NUCENG]

Link is fixed. It should be .html, rather than .htm

Thanks Astronuc. Must have cut off the l using copy and paste.

 

[PietKuip]

I'll have a stab at making it clear. Been lurking for a few weeks but this audio discussion has driven me spare and caused me to unlurk.

Take it from a career audio professional and\or look at the evidence below, it's not in any way the sound of unit #3 exploding. To me, a glance at the waveforms is enough to see it's a cut up effects track assembled from a 3 or 4 samples with some tweaks with effects and dynamics.

There are SO many things to speculate about, this audio track shouldn't be one of them. It's fake.

Thank you.

I have been looking around for infrasound recordings by seismic monitoring systems in Japan, but I could not find any. Maybe someone who reads Japanese could find some microbarograph recording somewhere?

 

[Azby]

to be followed by a concrete structure

[PLAIN]http://k.min.us/inx8Me.JPG

extracted from
http://www.tepco.co.jp/nu/fukushima-np/f1/images/f12np-gaiyou_4.pdf

the English version will become available later today or tomorrow
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f12np-gaiyou_e_4.pdf

this document also discusses the Areva plant (page 12)
and how Unit 2 is proposed to be cooled (pages 3-5)

Earlier and future version of these documents can be viewed by changing the last digit of the file name.

Thanks for finding that, Anton. The timeline shown on P2 is pretty vague, but it looks like 3-6 months from June to complete the polyethlyene "cover," and then work on the concrete "container" starts, beginning with "final design." I'd guesstimate that a concrete structure of that size would take the better part of a year.

 

[Calvadosser]

looking at this
zoom on poor quality video, seem conclusive with the fact that the multiple event "orange explosion and "vertical" movement were closer in there time line that I initially suspected.

I believe I see the birth of "mushroom" cloud sucking in the orange explosion.
There is also some kind of bright effect just behind the tower that is impossible do identity

It looks as if the orange explosion is sucked back but I think this is probably an illusion.

I think that what really happens is that the glowing orange mass of gas/debris cools as it expands and ceases to radiate visible orange light. The outermost area cools quickest, so it gives the appearance of the orange area retreating.

Films of some nuclear test explosions show this effect - the orange fireball ceases to glow and becomes a dark-coloured mushroom as it expands (though on a slower timescale than the Fukushima explosion).

 

[MadderDoc]

looking at this
zoom on poor quality video, seem conclusive with the fact that the multiple event "orange explosion and "vertical" movement were closer in there time line that I initially suspected.

I believe I see the birth of "mushroom" cloud sucking in the orange explosion.

I agree with your observation regarding the briefness of the temporal separation of the two phenomena, and the apparent sucking effect.

There is also some kind of bright effect just behind the tower that is impossible do identity

I am not sure what you are looking at there, but this could be it. During the development of the fire phenomenon, one sees light from the fire being reflected from those parts of the vertical structure elements of the exhaust stack which have a free line of sight to the fire, as well as to the observer. This forms a curious pattern of light changing in tune with the development of the flame, and the development of smoke interfering with the line of sight from the tower to the flame.

 

[NUCENG]

It looks like TEPCO is moving forward with it's plan to cover Unit 1 in a steel frame covered with polyethelene sheets. This news item doesn't give an expected date of completion, but I seem to recall September being bandied about previously.

http://www3.nhk.or.jp/daily/english/14_02.html
http://english.kyodonews.jp/photos/2011/05/90962.html

Also a news item reporting that the NISA says there's (probably?) no need to fill unit 1 RPV with water.

http://www3.nhk.or.jp/daily/english/13_26.html

I understand their intent is to stop the offsite releases, but how thick would it have to be to survive typhoon winds or wind driven debris impacts?

 

[Cire]

It's getting clear to me that an initial hydrogen burst cracked and depressurized the RPV or containment , followed by the ' emptying' of RPV and/or containment , the 'sucking ' effect produced by the rapid upward movement of gasses

It's highly unlikely you could over-pressurize the RPV. The support plumbing would fail first and the RPV would depressurize. You don't design the system such that your pressure vessel is what pops first.

Not to mention the dozen or so relief valves installed on the RPV to prevent this from happening.

 

[Borek]

edit : should I have just linked the image or is embeddeding it ok here?

Embedding is OK, if you can resize it a little bit (just trim the white on the left/right, picture is too wide now and can break forum formatting for some; in general we assume 800 px is a max width) it will be perfect. Contact me by PM if you have any troubles with resizing or reposting.

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).

 

[AntonL]

I understand their intent is to stop the offsite releases, but how thick would it have to be to survive typhoon winds or wind driven debris impacts?

They may use modern Kevlar reinforced fabrics.

And not to forget the wind loading of the structure, the weakest point will be the roof as it is shallow pitched to reliably shed rain water. If the wind direction is across the two slopes it will generate aerodynamic lift, like a wing, and possibly be the first mode of failure even before typhoon like wind speeds are reached.

And how they are going to work on the roof is beyond me if it is too hot for helicopters to overfly the open SFP

 

[NUCENG]

They may use modern Kevlar reinforced fabrics.

And not to forget the wind loading of the structure, the weakest point will be the roof as it is shallow pitched to reliably shed rain water. If the wind direction is across the two slopes it will generate aerodynamic lift, like a wing, and possibly be the first mode of failure even before typhoon like wind speeds are reached.

Thanks, I guess we'll see as they move forward.

 

[zapperzero]

Hey wait a minute. I thought a Chernobyl-like sarcophagus was not being contemplated. Any word on digging to bedrock to contain water pollution?
EDIT: Having perused the document, it seems they plan on patching up a torus which is cracked.

 

[swl]

I understand their intent is to stop the offsite releases, but how thick would it have to be to survive typhoon winds or wind driven debris impacts?

I don't think you understand. Here in Japan, the first thing the government does after a crime is to erect a a temporary shelter of blue vinyl to protect the crime scene from prying eyes and photographers. You know; they want to stop the offsite releases (of information). They may need to get some duct tape out after the typhoon, but it's hard to take pictures in the heavy wind and rain anyway, so no big loss.

I don't imagine their blue vinyl enclosure will do us much good for containment of radiation when they've already lost containment inside multiple layers of high tech alloys and steel reinforced concrete. And how is the tent going to stop the water from flowing out into the ground water and ocean?

 

[MadderDoc]

GJBRKS wrote:

It's getting clear to me that an initial hydrogen burst cracked and depressurized the RPV or containment , followed by the ' emptying' of RPV and/or containment , the 'sucking ' effect produced by the rapid upward movement of gasses

It's highly unlikely you could over-pressurize the RPV. The support plumbing would fail first and the RPV would depressurize. You don't design the system such that your pressure vessel is what pops first.

Not to mention the dozen or so relief valves installed on the RPV to prevent this from happening.

Based on the available data of the reactor parameters, the combined system of RPV and support plumbing of unit 3 failed already on March 13th (between 9:10 and 9:25 the RPV pressure dropped abruptly from 7.3 MPa to 0.45 MPA, while drywell pressure increased from 0.46 to 0.53 MPa.) This would seem to imply that the dozen or so preventive relief valves you mention, failed too.

Consequently, on March 14th, the day of the explosion, the RPV and the PCV were no longer sharply separated volumes, and a depressurizing of the PCV at that stage would also lead to a depressurizing of the RPV . The data available up to and after the explosion indicates a depressurizing of both vessels in connection with the explosion of no less than 0.1 MPa.

 

[elektrownik]

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

 

[GJBRKS]

It's highly unlikely you could over-pressurize the RPV. The support plumbing would fail first and the RPV would depressurize. You don't design the system such that your pressure vessel is what pops first.

Not to mention the dozen or so relief valves installed on the RPV to prevent this from happening.

I said nothing about over-pressurization.

I talked about sudden depressurization and resulting volume expansion

The RPV was known to handle at least 70 atm

 

[yakiniku]

A couple of WSPEEDI forecasts have been released by MEXT (24th and 25th March, towards the bottom of the page):

http://www.mext.go.jp/a_menu/saigaijohou/syousai/1305747.htm

The more interesting link is for the 25th March which contains estimated accumulated iodine 131.

http://www.mext.go.jp/component/a_menu/other/detail/__icsFiles/afieldfile/2011/05/10/1305799_0325.pdf