Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[TCups]

and this: http://www.houseoffoust.com/fukushima/heat.html ?

Are you familiar with the digital imaging terms "window width" and "window level"? If so, go back on every image and look carefully at the color bar on the left to determine where the "center" temperature is, the total spread of high and low temperatures displayed, and the absolute values assigned to each color. Some things that look "hotter" just because they are more toward the red end of the spectrum in one image are not necessarily hotter than something green in the next image, when you check the scale.

I confess I haven't gone frame by frame through your analysis and questions, but at a glance, I can tell you that you have to be very careful comparing one image to the other. The time lapsed during the acquisition of the image and the color scale ascribed to the image vary significantly, I believe.

 

[M. Bachmeier]

Are you familiar with the digital imaging terms "window width" and "window level"? If so, go back on every image and look carefully at the color bar on the left to determine where the "center" temperature is, the total spread of high and low temperatures displayed, and the absolute values assigned to each color. Some things that look "hotter" just because they are more toward the red end of the spectrum in one image are not necessarily hotter than something green in the next image, when you check the scale.

I confess I haven't gone frame by frame through your analysis and questions, but at a glance, I can tell you that you have to be very careful comparing one image to the other. The time lapsed during the acquisition of the image and the color scale ascribed to the image vary significantly, I believe.

Even when looking at small variations, a color contrast illusion can make simple observation inconclusive and misleading. How much detail is being offered in the IR?

P. S. Does anybody have specs? Most modern IR is digitally enhanced to account for wave distortion like observatory (digital) astronomical observation.

 

[TCups]

Even when looking at small variations, a color contrast illusion can make simple observation inconclusive and misleading. How much detail is being offered in the IR?

Yes. The bright colors look impressive on the web and on TV sound bytes, but at least in medical imaging, color scales are seldom used. Monochrome or grayscale are preferred. Either a very big difference with a wide window can look like a very small difference with a narrow window.

In imaging, "detail" is usually reserved for spatial resolution. Some of the IR images seemed to have wide windows, little overall difference in the color scale, and a lot of detail. Some of the color images appear to "bloom" with the colors used and all detail is lost.

I will try to go through the IR mages later (tonight is the NCAA basketball finals, after all).

You can see, though, that all of these images have been windowed and leveled so as to identify the single hottest point on the image, which is the annotated temperature on the labels.

 

[razzz]

After dousing with water, I think the point is that there are hot spots where there should be no hot spots. Everything around the pool should be ambient temp. Even inside the pool it's inconsistent.

 

[M. Bachmeier]

Yes. The bright colors look impressive on the web and on TV sound bytes, but at least in medical imaging, color scales are seldom used. Monochrome or grayscale are preferred. Either a very big difference with a wide window can look like a very small difference with a narrow window.

In imaging, "detail" is usually reserved for spatial resolution. Some of the IR images seemed to have wide windows, little overall difference in the color scale, and a lot of detail. Some of the color images appear to "bloom" with the colors used and all detail is lost.

I will try to go through the IR mages later (tonight is the NCAA basketball finals, after all).

You can see, though, that all of these images have been windowed and leveled so as to identify the single hottest point on the image, which is the annotated temperature on the labels.

Yes thank you I forgot (NCAA), see you later:), but thank you+.

 

[denislaurent]

Same question about Pressure & Temperature in Unit#1 vessel.

In fact, Tepco release 2 vessel pressure data (A & B).
They are consistent until March 26 (end of massive cooling)
But they are now diverging, with PA showing the same trend than in D/W and S/C
but PB continuously climbing for now one week+.

It would be good to know the exact location of the sensors.

Please note too that radiation level in drywell is not continuously decreasing
as for units #2 and #3.

Has somebody more information / Hypothesis ?

 

[Jorge Stolfi]

what is going on with core pressure in number 1? It doesn't deem to correlate with temperature readings?

I have no idea; I just write down the TEPCO numbers.

Actually I still do not know how and where those temperatures are measured. I GUESS that they are readings of thermocouples attached to the ouside of (or embedded into) the wall of the reactor's pressure vessel. I have read claims that the "dry"well too is being sprayed with water, is that right? If so the numbers may be meaningless...

 

[M. Bachmeier]

I have no idea; I just write down the TEPCO numbers.

Actually I still do not know how and where those temperatures are measured. I GUESS that they are readings of thermocouples attached to the ouside of (or embedded into) the wall of the reactor's pressure vessel. I have read claims that the "dry"well too is being sprayed with water, is that right? If so the numbers may be meaningless...

P. S. Temperature could be reasonably calculated at a given distance re analogue.

With plants in excess of 40 years old there would be analogue gauges, much of which could survive strong pressure variances, being that high pressure gauges are liquid filled and stainless steel. The real question is if those gauges are ported by pressure lines to be (parallel) accessible (outside of intolerable hazard) for interpretation.

 

[MadderDoc]

It is reported that the cause of the unit 4 building damage was a H2 explosion caused by overheating of the discharged fuel in the U4 spent fuel pool. To the best of my knowledge, there is no photgraphic evidence of the explosion. Something that has troubled me since the first pictures of the Unit 4 damage on 16March, was whether there actually was a loss of inventory in the U4 spent fuel pool. Attached is a markup of the first photograph that was released on 16 March showing the U4 buiding damage. One can find the photo on Reuters site. This photo was taken before any water injection/spray in Unit 4. Perhaps, I'm missing something, but it sure looks to me like there was still significant water in the fuel pool on March 16. Anyone have an alternative speculation?

Some specks of lights, reminicent of reflections in a water surface, can be seen at about 1:33 in this video from March 16th, supporting your contention;

(The attachment below is just to show where to look. For the proper experience, one must watch the video.)

If not by force of hot fuel in a dried up SFP, the damage to unit 4 would seem to me to have been caused by hot fuel being stashed somewhere _else_ up there.

For what it is worth, webcam photos the day unit 4 was destroyed:
http://www.gyldengrisgaard.dk/tepcowebcam/tepweb20110315.html
We are looking in from the south. It is readily apparent that all damage done to the south face of unit 4 occurred in the morning between 6 and 7 am -- at 6 am the buiding looks quite fine, while at 7 am it is a total wreck, and the sky above it is swarming with choppers.

 

[Jorge Stolfi]

Now it is my turn at hallucinating: In this image (previously posted by AntonL) I see a couple of smashed fuel assemblies. Rods, the square envelope, even the handle at the top. (Disclaimer: I just had wine for dinner...)

 

[AtomicWombat]

MECHANISM FOR CASK TRANSFER OF NEW AND SPENT FUEL RODS?
It would make more sense to put the dry cask in a small pool, pumped dry, then flood the small pool, then open the cask underwater, then transfer the new rods directly to the reactor core underwater. It would also seem logical to transfer the spent rods under water to a flooded small pool, containing an open cask, then to close and decontaminate the exterior of the cask before the crane takes it back for loading on the truck. Just guessing.

These videos help illustrate the transfer of spent fuel rods to a dry cask - the first one seems to relate to Mark I BWRs:
http://www.youtube.com/watch?v=rh6FeQWuhCs"
http://www.youtube.com/watch?v=fkz-3e-BYSk"
http://www.youtube.com/watch?v=cisdwv5lPwk&feature=related"
http://www.youtube.com/watch?v=CjGD2oL9fJ8&feature=related"
http://www.youtube.com/watch?v=-gzyvh0cPN4&feature=related"
http://www.youtube.com/watch?v=gS9sJHp0q2c&feature=related"
http://www.youtube.com/watch?v=qj4gZogu_BI&NR=1"
http://www.youtube.com/watch?v=nNmtV-ljFWg&feature=related"
http://www.youtube.com/watch?v=qJmXfWA3m_U&NR=1"
http://www.youtube.com/watch?v=AQIo1-8H3Ww&NR=1"

 

[TCups]

Now it is my turn at hallucinating: In this image (previously posted by AntonL) I see a couple of smashed fuel assemblies. Rods, the square envelope, even the handle at the top. (Disclaimer: I just had wine for dinner...)

Conservatively, even the much older spent fuel rods would very soon reach a temperature of several hundred ºC once removed from the pool and exposed to air. Somehow, I recall the figure of a heat up rate of 1ºC per second if the rod is removed from the water. If those were fuel rods and if they were exposed to air since the explosion, then the IR thermal imagery would almost certainly show them as the hottest thing in the image, I suspect. I could be wrong, though . . .

 

[MadderDoc]

BLAST DAMAGE AT UNIT 3



@ MadderDoc, Fred, et. al.:

Re: New video. Attached is a screenshot from the viedo with and without annotations of what I think I see. As ever, I say the blast came out of the primary containment, through failed seals on the transfer ("cattle") chute gate. But then, it is all too easy to see what you expect to see and want to see. Comments?

http://i306.photobucket.com/albums/nn270/tcups/Screenshot2011-04-04annotated.png

http://i306.photobucket.com/albums/nn270/tcups/Screenshot2011-04-04at50940PM.png

Agreed except looking at other pictures rather than having been blasted from below, the bent girders seem to me to have been hit heavily by something coming from above. Looking for a blast from below I think the area of the SPF is the only candidate. Perhaps during the assumed hydrogen explosion, the SPF pit came to act like a barrel for the blast, shooting the parked FHM high in the air, only to come down on the north end of the building, just about where those girders were.

 

[TCups]

It could well be so.

 

[AntonL]

Spread of radioactivity 4 to 7 April - these are relative values as actual is not known

[PLAIN]http://www.dwd.de/bvbw/generator/DWDWWW/Content/Oeffentlichkeit/KU/KUPK/Homepage/Aktuelles/Sonderbericht__Bild5,templateId=poster,property=poster.gif

 

[AtomicWombat]

I see the rails for the overhead crane as highlighted in red, and the large wench on the overhead crane as highlighted in yellow.

large wench ?

I suppose that's one way to get employees to work in high radiation zones!

 

[TCups]

large wench ?

I suppose that's one way to get employees to work in high radiation zones!

Sorry - I looked for an appropriate picture to illustrate, but I couldn't find one

 

[aruna]

Trench dimensions:
3x4x76 meters.
Source: http://www3.nhk.or.jp/daily/english/28_h37.html

The trench is only 4 m high. In its 16 m inspection shaft, the water is 14.9 m high :?
http://goo.gl/KXFTe

Doesn't that mean that the 4 m trench is already full :?

 

[razzz]

The trench is only 4 m high. In its 16 m inspection shaft, the water is 14.9 m high :?
http://goo.gl/KXFTe

Doesn't that mean that the 4 m trench is already full :?

At this rate of discharge (in the pics) it will take a while to get full.

[URL]http://www.asahi.com/photonews/gallery/fukushimagenpatsu2/images/0402_plant2.jpg[/URL]
[URL]http://www.asahi.com/photonews/gallery/fukushimagenpatsu2/images/0402_plant1.jpg[/URL]

They could stop dumping water on the reactor #2 core to cool it, because that is where the water originates from, but then the core would heat up and make more trouble, so we just live with a little pollution/contamination for awhile.

 

[Jorge Stolfi]

Updated plots of reactor data #1--#3 from NISA / METI, up to release 74 (apr/05 08:00).

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/plots/cur/Main.html

No big news, trends basically the same as yesterday.
I still do not know what those numbers mean.
All the best.

 

[AtomicWombat]

From:
http://www3.nhk.or.jp/daily/english/05_25.html"

"Tokyo Electric Power Company says it detected 300,000 bequerels of iodine-131 per 1 cubic centimeter, or 7.5 million times higher than the legal limit in samples taken around the water intake of the No. 2 reactor at 11:50 AM on Saturday.

It also found 200,000 bequerels or 5 million times higher than the limit in samples taken at 9AM on Monday.

Monday's sample also shows 1.1 million times higher than the national limit of cesium-137 whose half-life is 30 years."

They keep "moving the goal posts". It used to be the iodine-131 concentration was 5000 times higher than would normally be found in the reactor. And the level of cesium-137 is not even given - just referenced to the national limit.

I assume I-131 at 300 Mbq/m^3 is a lot.

 

[|Fred]

http://i306.photobucket.com/albums/nn270/tcups/Screenshot2011-04-04annotated.png
http://i306.photobucket.com/albums/nn270/tcups/Screenshot2011-04-04at50940PM.png

I don't think its a transfer chute but rather a pool. As far the rest of the picture is concern I've been trying to read the picture for a few hours and.. I'm not sure of what I'm seeing.


the video is conveniently cut from 13:22 to 15:xx

 

[Jorge Stolfi]

OK, it seems that the questions "How are the RPV temperatures measured?" and "Are those things broken fuel rods?" are not going to get answered that soon.

How about this one, "Why is the word 'pressure' automatically linked in this forum, while 'temperature' is not?"?

 

[Giordano]

From:
http://www3.nhk.or.jp/daily/english/05_25.html"

"Tokyo Electric Power Company says it detected 300,000 bequerels of iodine-131 per 1 cubic centimeter, or 7.5 million times higher than the legal limit in samples taken around the water intake of the No. 2 reactor at 11:50 AM on Saturday.

It also found 200,000 bequerels or 5 million times higher than the limit in samples taken at 9AM on Monday.

Monday's sample also shows 1.1 million times higher than the national limit of cesium-137 whose half-life is 30 years."

They keep "moving the goal posts". It used to be the iodine-131 concentration was 5000 times higher than would normally be found in the reactor. And the level of cesium-137 is not even given - just referenced to the national limit.

I assume I-131 at 300 Mbq/m^3 is a lot.

And 300 Gbq/m^3 is even more...

 

[TCups]

I don't think its a transfer chute but rather a pool. As far the rest of the picture is concern I've been trying to read the picture for a few hours and.. I'm not sure of what I'm seeing.


the video is conveniently cut from 13:22 to 15:xx

@Fred

Do you agree with the position of the crane? Do you think that thin line near the lateral margin of the crane is a short section of an arc? Do you think that jet of steam is under pressure? If those fit, then what other part of a pool comes that near the primary containment's plug other than the transfer chute?

There appears to be a label peeling off the side of the crane. Is that a clue that means anything to you?

PS: Fred - thanks for your feedback. I value your opinions.

 

[FishmanGeertz]

I hope that nuclear power plants all around the world are given safety upgrades to make sure than the Fukashima incident can not happen again.

Are nuclear power plants in earthquake-prone areas such as in California, vulnerable to having their cooling systems knocked out by earthquakes and tsunamis?

 

[razzz]

http://en.wikipedia.org/wiki/Criticality_accident"

Accident types

Criticality accidents are divided into one of two categories:

* Process accidents, where controls placed to prevent any criticality are breached,

and

* Reactor accidents, where deliberately achieved criticality in a nuclear reactor becomes uncontrollable. Excursion types can be classified into four categories depicting the nature of the evolution over time:

and http://en.wikipedia.org/wiki/Chernobyl_disaster#Experiment_and_explosion"

...It was not possible to reconstruct the precise sequence of the processes that led to the destruction of the reactor and the power unit building, but a steam explosion, like the explosion of a steam boiler from excess vapor pressure, appears to have been the next event. There is a general understanding that it was steam from the wrecked channels entering the reactor's inner structure that caused the destruction of the reactor casing, tearing off and lifting the 2,000-ton upper plate, to which the entire reactor assembly is fastened. Apparently, this was the first explosion that many[who?] heard.[23]:366 This explosion ruptured further fuel channels, and as a result the remaining coolant flashed to steam and escaped the reactor core. The total water loss in combination with a high positive void coefficient further increased the reactor power.

A second, more powerful explosion occurred about two or three seconds after the first; evidence indicates that the second explosion resulted from a nuclear excursion.[24] The nuclear excursion dispersed the core and effectively terminated this phase[clarification needed] of the event...

http://www.youtube.com/watch?v=T_N-wNFSGyQ"

Listen to the link. Maybe: The first explosion (hydrogen ignites?) voids the atmosphere and causes water to flash to steam across the reactor and then sounds like it happens again, each with it's own explosion and the final sound you hear in the heavy crossbeam hitting the desk with a resounding metallic thud and deep ringing. [edit: disregard hearing the beam land, it's localized background noise the mike picked up, I think)

No go zone, massive release of contamination at this time, then the company later states they will probably never be able to approach Unit 3.

 

[shogun338]

I don't think its a transfer chute but rather a pool. As far the rest of the picture is concern I've been trying to read the picture for a few hours and.. I'm not sure of what I'm seeing.the video is conveniently cut from 13:22 to 15:xx

Your right . Its the smaller pool on the right side of reactor if your looking at it from turbine building . Move left reactor that is leaking steam around it then main spent fuel pool on far left . I have a over flight video on my computer and have lined up the remaining beams and found the place in the photo . Unit 4 has a smaller spent fuel pool on right side so my guess is the layout is the same for Unit 3 .

 

[shogun338]

A – Unit 3 turbine building containing the main turbine, main generator, condenser, condensate pumps, and condensate booster pumps. Roof damage possibly caused by debris from the Unit 3 reactor building (B) explosion
B - Unit 3 reactor building with extensive damage caused by hydrogen explosion
C – Unit 2 offgas line that transports air pulled from the condenser inside the Unit 2 turbine building during normal operation to the offgas building for treatment to reduce radioactivity levels before discharge to the atmosphere
D – Unit 3 offgas line that transports air pulled from the condenser inside the Unit 2 turbine building during normal operation to the offgas building for treatment to reduce radioactivity levels before discharge to the atmosphere
E – Unit 3 reactor building (B) exhaust line to the stack showing extensive damage
F – Unit 3 truck bay used to deliver canisters of new fuel assemblies into the reactor building (B) and its refueling floor
G – Unit 3 access hatch connecting the truck bay elevation with the refueling floor elevation inside the Unit 3 reactor building (B)

 

[Maxion]

http://en.wikipedia.org/wiki/Criticality_accident"



and http://en.wikipedia.org/wiki/Chernobyl_disaster#Experiment_and_explosion"



http://www.youtube.com/watch?v=T_N-wNFSGyQ"

Listen to the link. Maybe: The first explosion (hydrogen ignites?) voids the atmosphere and causes water to flash to steam across the reactor and then sounds like it happens again, each with it's own explosion and the final sound you hear in the heavy crossbeam hitting the desk with a resounding metallic thud and deep ringing. [edit: disregard hearing the beam land, it's localized background noise the mike picked up, I think)

No go zone, massive release of contamination at this time, then the company later states they will probably never be able to approach Unit 3.

As stated many times previously in this thread the chernobyl reactor design has nothing in common with the one at fukushima. You cannot draw parallels between the two.

 

[razzz]

As stated many times previously in this thread the chernobyl reactor design has nothing in common with the one at fukushima. You cannot draw parallels between the two.

It's not the designs, it's the reactions. Why 3 explosions in that link for unit 3?

 

[Godzilla1985]

Echoes

 

[AtomicWombat]

"I assume I-131 at 300 Mbq/m^3 is a lot."

And 300 Gbq/m^3 is even more...

What's a few orders of magnitude between friends...

 

[shogun338]

It's not the designs, it's the reactions. Why 3 explosions in that link for unit 3?

The sound in that video has been added in by someone . I have the video of Unit 3 exploding and there is no sound like that . Where did they get the sound that was added to the video ?

 

[Cire]

Do you mean temperature is higher than is being reported? Do you have some supporting reference, link etc.?

Thermocouples have a known failure mode when overheated. First the precision opens up and then an offset develops. It's call decalibration and the sensor will return what appears to be a correct value, when it isn't.

This is why the IAEA keeps saying "The validity of the RPV temperature measurement at the feed water nozzle is still under investigation."

The fact that the water feed nozzle is showing a higher temperature (253 °C in unit 1) is a good indication of a failure. The feed water nozzle has the highest flow of the coldest water in the reactor at this time. At these injection rates the reported temperature is not correct.