Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[ndray]

So far, I don't seen any contradiction to the containment explosion with blast of fuel rods and perhaps some scattered fragments of fuel rods outside of the FOV. But we are drawing conclusions of a picture of a TV picture at low resolution.

An analysis expecting damages on the SPF structure after the explosion on #3.
From the french institude for nuclear safety. (IRSN)
Link (french document) : http://www.irsn.fr/FR/Actualites_pr...Seisme-Japon_Point-situation-20032011-06h.pdf

L’IRSN estime que la dalle anti-missile située à la verticale de la cuve et de l’enceinte de
confinement a dû être détruite lors de l’explosion hydrogène du 14 Mars 2011. Si les ouvrages qui supportent cette dalle ont également été touchés, il est envisageable, outre les fuites éventuelles, que le niveau d’eau maximal possible au dessus des assemblages combustibles entreposés dans la piscine soit diminué (dans le pire cas : 1 mètre au dessus du haut des assemblages). Ceci expliquerait les débits de dose très importants au droit du bâtiment et confirmerait les efforts pour maintenir en eau cette piscine.

Pool of reactor No. 3
IRSN believes that the missile proof slab located vertically above the vessel and the containment (see Annex 1) has been destroyed by the hydrogen explosion of the 14th of March 2011. If the structures that support this slab were also affected, it is conceivable that the possible maximum water level above the fuel assemblies stored in the pool would be reduced (in the worst cases: 1 meter above the top of the assemblies). This would explain the very high radiation levels to the top of the building and the constant efforts needed to maintain water level in this SPF.

 

[TCups]

"They", et al? 128ºC? Above the boiling point of water? In the spent fuel pool? I 'spec steam could be 128ºC, but not water in a pool, but I would need to know if any steam was rising when this image was obtained.

Also, if the window/level of the color IR spectroscopy were set at a "white" level =128ºC = hottest thing in the image, then I 'spec that everything above 128ºC would also be white, but I don't know the window/level of the color image or what parameters they used to measure the true temperature of the SFP, or even if the hottest thing on the image is what is being measured as the SFP temp. Not enough information in that single image. I do know were it looks hottest now, though, both in Bldg 3 and 4. And I do know that Bldg 3 is hotter than Bldg 4, apparently right where the smoke/steam seemed to be venting after the explosion and where my earlier 'spec was that it was the most likely site where a defect in the primary containment might occur after an explosion. I also 'spec that it wasn't hot "corium" that was seen hanging out the hole on the 3-side of Unit 4.

But you know what the constipated fly said, right? -- "I spec not."

Sorry if I speculate too much. Apologies.

 

[M. Bachmeier]

"They", et al? 128ºC? Above the boiling point of water? In the spent fuel pool? I 'spec steam could be 128ºC, but not water in a pool, but I would need to know if any steam was rising when this image was obtained.

Also, if the window/level of the color IR spectroscopy were set at a "white" level =128ºC = hottest thing in the image, then I 'spec that everything above 128ºC would also be white, but I don't know the window/level of the color image or what parameters they used to measure the true temperature of the SFP, or even if the hottest thing on the image is what is being measured as the SFP temp. Not enough information in that single image. I do know were it looks hottest now, though, both in Bldg 3 and 4. And I do know that Bldg 3 is hotter than Bldg 4, apparently right where the smoke/steam seemed to be venting after the explosion and where my earlier 'spec was that it was the most likely site where a defect in the primary containment might occur after an explosion. I also 'spec that it wasn't hot "corium" that was seen hanging out the hole on the 3-side of Unit 4.

But you know what the constipated fly said, right? -- "I spec not."

Sorry if I speculate too much. Apologies.

As long as your looking for answers and not drawing unfounded conclusions your contributing to understanding. The problem is that much of the information needed exists but is not being provided.

I don't know why we have an international watchdog if it doesn't bark loudly when pertinent information is withheld from public scrutiny.

 

[TCups]

An analysis expecting damages on the SPF structure after the explosion on #3.
From the french institude for nuclear safety. (IRSN)
Link (french document) : http://www.irsn.fr/FR/Actualites_pr...Seisme-Japon_Point-situation-20032011-06h.pdf

L’IRSN estime que la dalle anti-missile située à la verticale de la cuve et de l’enceinte de
confinement a dû être détruite lors de l’explosion hydrogène du 14 Mars 2011. Si les ouvrages qui supportent cette dalle ont également été touchés, il est envisageable, outre les fuites éventuelles, que le niveau d’eau maximal possible au dessus des assemblages combustibles entreposés dans la piscine soit diminué (dans le pire cas : 1 mètre au dessus du haut des assemblages). Ceci expliquerait les débits de dose très importants au droit du bâtiment et confirmerait les efforts pour maintenir en eau cette piscine.

Pool of reactor No. 3
IRSN believes (speculates?) that the missile proof slab located vertically above the vessel and the containment (see Annex 1) has been destroyed (vaporized? shattered? popped off like a giant cork?) by the hydrogen explosion (where?) of the 14th of March 2011. If the structures that support this slab were also affected (the side of the SFP where the gate to the transfer chute is?), it is conceivable (one could speculate) that the possible maximum (maximum? - interesting choice of words) for water level above the fuel assemblies stored in the pool would be reduced (in the worst cases: 1 meter above the top of the assemblies). (if the earthquake didn't slosh it out like this morning's coffee at the speed bump, and if the shock wave of the blast that destroyed the missile proof plug didn't spill any more, and if the only leakage from the pool was at a level no lower than the transfer chute, and if all the dumping and spraying done before the radiation levels rose too high helped before too much more boiled off at 128ºC?) This (and only this?) would explain the very high radiation levels to the top of the building and the constant efforts needed to maintain water level in this SPF.

You may be right about the speculation thing after all. I am sorry, everyone. It is my nature. I just can't help myself sometimes. I will try do better. I promise.

 

[AntonL]

As long as your looking for answers and not drawing unfounded conclusions your contributing to understanding. The problem is that much of the information needed exists but is not being provided.

I don't know why we have an international watchdog if it doesn't bark loudly when pertinent information is withheld from public scrutiny.

http://mdn.mainichi.jp/mdnnews/news/20110319p2a00m0na005000c.html" published on 19th the following "The footage taken from an RQ-4 Global Hawk drone was passed on to the Japanese government with permission for public release from the U.S. Air Force. U.S. military sources said that the decision to release the footage -- or not -- was up to the Japanese government." Although published on 19th it is still the No1 article read on the 21st

The USA has every opportunity to release information but refrains. I am pretty sure watchdog officials also have this footage and expert analysis thereof but are bound to diplomatic secrecy.

You may be right about the speculation thing after all. I am sorry, everyone. It is my nature. I just can't help myself sometimes. I will try do better. I promise.

TCups you are doing very well, no need to change

 

[PietKuip]

An http://www.slideshare.net/iaea/4-briefing-radiation-protection-20-03-2011a" regarding radiation levels

and

ongoing http://www.mext.go.jp/english/" published by Japanese government.

The IAEA lists 15 kBq per kg of iodine-131 in spinage and up to 6100 Bq/kg in spring onions from Ibaraki prefecture.

Those are levels to worry about. Agriculture in the region seems impossible this year.

 

[Maxion]

The IAEA lists 15 kBq per kg of iodine-131 in spinage and up to 6100 Bq/kg in spring onions from Ibaraki prefecture.

Those are levels to worry about. Agriculture in the region seems impossible this year.

Iodine does have a half-life of 8 days. It will be gone quite rapidly. 15kBq isn't THAT much radiation.

 

[dgdd]

I propose some modifications (in bold) to translation initially posted by ndray:

IRSN speculates that the missile proof slab located vertically above the vessel and the containment (see Annex 1) has been shattered then scattered by the hydrogen explosion (where?) of the 14th of March 2011. If the structures that support this slab were also affected (the side of the SFP where the gate to the transfer chute is?), it is conceivable (one could speculate) that, besides possible cracks, the possible maximum (maximum? - interesting choice of words) for water level above the fuel assemblies stored in the pool would be reduced (in the worst cases: 1 meter above the top of the assemblies).

Note: This is not about the water level in this pool, this is only about the water capacity of the pool after some of its walls have been curtailed by the fall of this shattered and scattered slab and support.

[continued]
This would be sufficient to explain the very high radiation levels close to the building and the significant and constant efforts needed to maintain water level in this SPF.

You may be right about the speculation thing after all. I am sorry, everyone. It is my nature. I just can't help myself sometimes. I will try do better. I promise.

Maybe the information here is about the presence of thick slab pillar(s) just near the walls of this pool.

 

[rhody]

FYI: For perspective:

http://www.cnbc.com/id/42112536?slide=1"

Rhody... (no dark humor intended, the red face that is... well maybe, just a little)

 

[TCups]

I propose some modifications (in bold) to translation initially posted by ndray:

Note: This is not about the water level in this pool, this is only about the water capacity of the pool after some of its walls have been curtailed by the fall of this shattered and scattered slab and support.



Maybe the information here is about the presence of thick slab pillar(s) just near the walls of this pool.

Where?
http://img863.imageshack.us/img863/3206/reactor.jpg

 

[TCups]

link is not working

Sorry. I will try later. OP with faulty links deleted. Lots of folks must have been looking. Bandwidth exceeded.

OK, try again.

If the fuel transfer chute and gate (yellow) were the weak spot. A blow out here would cause a blast from inside the primary containment to blow out and up from the south end of the building, blow out the roof over the south end, and if the heavy crane (blue) partially shielded the north wall, perhaps collapse it inward with portions of the roof girders over it. Venting stem would come from the region of the chute.

 

[jensjakob]

Those IR images are interesting. Why are there hotspots on the ground between 3 & 4? What are the cause of those hotspots? Very interesting.

 

[joema]

The four-reactor Fukushima II Daini plant was just 7 miles due south of the Fukushima I Daiichi plant. It was on the coast just like the Daiichi plant, was hit by the same earthquake and Tsunami, and to my knowledge is of similar design.

Why was it not as badly affected?

 

[swimmer]

FYI: For perspective:

http://www.cnbc.com/id/42112536?slide=1"

Rhody... (no dark humor intended, the red face that is... well maybe, just a little)

Tokaimura 1999, wasn't TEPCO involved?
Goiania, Brazil 1987, that blue barbeque scene, is that where the expression "laughing in the face of death" came from?
More horrible than horror stories these accidents. Sobering knowledge. We learn from our mistakes, yes, but some mistakes are incomprehensably awful.

Accidents will happen. I accept that.
Playing with fire this is not, I accept that also.
It's the cover-up reflexes and twisting of numbers afterwards that I find most depressing.

 

[swimmer]

The four-reactor Fukushima II Daini plant was just 7 miles due south of the Fukushima I Daiichi plant. It was on the coast just like the Daiichi plant, was hit by the same earthquake and Tsunami, and to my knowledge is of similar design.

Why was it not as badly affected?

Nuclear PR is familiar with the phrase 'freak accident', Daini (= Plant 2 in Japanese) experienced freak luck.

Seen that slowed-down video footage from the helicopter over Daiichi? Early on you see tarmac ripped like paper by the earthquake. A metre away and it's still intact. Earthquake causes local surface damage over a great many locations. Hope this unscientific explanation helps.

 

[doc_u]

The four-reactor Fukushima II Daini plant was just 7 miles due south of the Fukushima I Daiichi plant. It was on the coast just like the Daiichi plant, was hit by the same earthquake and Tsunami, and to my knowledge is of similar design.

Why was it not as badly affected?

Wikipedia is our friend here:

Fukushima Daini (Daini means second or two)

Unit	First criticality     Reactor    Architecture	Construction
1	31/07/1981            Toshiba	 Toshiba	Kajima
2	23/06/1983	      Hitachi	 Hitachi	Kajima
3	14/12/1984	      Toshiba	 Toshiba	Kajima
4	17/12/1986	      Hitachi	 Hitachi	Shimizu Takenaka

So, it appears to be somewhat dissimilar to the first Fukushima plant, and obviously built much later, brought online AFTER TMI, so perhaps some lessons learned from that...

The real story for me (and that the media appears not to care about) is that out of the very large number of NPPs in Japan, we are really only facing major issues with 4 reactors at one plant.

Show THIS graphic, news people:

-doc

 

[TCups]

Those IR images are interesting. Why are there hotspots on the ground between 3 & 4? What are the cause of those hotspots? Very interesting.

Where? I see heat signatures from Unit 3 and 4, but not on the ground.

 

[Maxion]

Nuclear PR is familiar with the phrase 'freak accident', Daini (= Plant 2 in Japanese) experienced freak luck.

Seen that slowed-down video footage from the helicopter over Daiichi? Early on you see tarmac ripped like paper by the earthquake. A metre away and it's still intact. Earthquake causes local surface damage over a great many locations. Hope this unscientific explanation helps.

Also, the tsunami did not destroy the generators at Daiini and they got offsite power back quite quickly.

 

[jensjakob]

Where? I see heat signatures from Unit 3 and 4, but not on the ground.

Picture in post 721, I interpret the green areas (on the roofs?) as hotspots too

 

[jensjakob]

Very intersting.

Here we see no temperatures for SFP, but 5&6 are (in my interpretation) less critical than 1+2+3+4.
http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1300544332P.pdf

Then in this newsclip,
http://www3.nhk.or.jp/daily/english/20_33.html
we read "Water temp at 2 reactors below boiling point" - and the article covers 5+6.

I do NOT like the implications of these 2 items...

What are the temp at SPF 1+2+3+4?

My problem is that I begin to think that the information from JAIF is intended to be enough to keep people from asking why info isn't released - but at the same time the information is cleverly designed to omit the critical parts...

I would also still VERY much like to see radiation readings ABOVE the reactors. On ground level the buldiing shields a lot of the radiation, so the numbers around the site does not show the actual levels of radiation... :-(

 

[PietKuip]

Picture in post 721, I interpret the green areas (on the roofs?) as hotspots too

The green spots in the second image are patches of surface that are cooler (or have lower IR emissivity) than the rest of the roof.

 

[jensjakob]

The green spots in the second image are patches of surface that are cooler (or have lower IR emissivity) than the rest of the roof.

Apologies for misinterpretating. Sorry!

 

[TCups]

Let's say warm spots, comparatively. And I believe them to be on roofs. Which asks the question why there aren't corresponding warms spots on the ground in a symmetric distribution. Don't know what if any clean up has been done. Blast debris on the ground would cool more quickly than those on the roofs, perhaps.

If the color IR image scale is such that white is displayed at temps of only -- what was it? -- 128ºC, then these wouldn't seem incredibly hot. Remember, though, that thermal images can be windowed and leveled to make most everything look hot or cold. The colors are arbitrarily assigned and the temperature differences between colors can be very great or very small. We don't know the WW/WL or temp scales of these are.

It would be interesting to see the relative temps of the debris field and the square-looking thing on the roof that the helicopter fly over was looking at carefully -- to the northwest, in one of the earlier posts.

 

[jensjakob]

Also interesting to see that no 1 has hotspots at each side of the concreteplug, just where those gates are between the pools, and the drywell head...

 

[bondboy]

Great question! I want to know the readings above and within the reactors. I pulled this from NHK. My follow up question is what are the other 4 materials found? They keep quoting Iodine131 levels but never mention the other materials made by fission.
Anyone care to venture a guess as to what they could have found?

http://www3.nhk.or.jp/daily/english/21_22.html
5 radioactive materials detected
Tokyo Electric Power Company says some of the nuclear fuel at the Fukushima Daiichi nuclear power plant has apparently been damaged, as higher levels of radioactive materials have been detected in the vicinity.

The utility on Monday released the results of a radiation survey carried out at the plant on Saturday.

Officials detected in the air 5 radioactive materials that are generated by nuclear fission.

The level of iodine 131 was 5.9 milibecquerels per cubic centimeter. That's about 6 times the permissible level for workers without protective masks.

The density of the other substances was also higher than usual, but within safety standards.

The utility says the radiation is likely to have come from the damaged reactors, and added that it will check radiation levels daily.

The company also says it has no plan to halt efforts to restore power and pour water into reactors, as these activities pose no risk to workers as long as they wear protective masks.
Monday, March 21, 2011 19:35 +0900 (JST)

 

[jensjakob]

A whole lot of NPP diagrams and layouts - though no BWR as far as I can see:
http://econtent.unm.edu/cdm4/browse.php?CISOROOT=/nuceng

 

[TCups]

The green spots in the second image are patches of surface that are cooler (or have lower IR emissivity) than the rest of the roof.

The green is typically warmer than blue. By comparison, for example, the roofs of the turbine buildings in the lower part of the image (foreground) are a nice green color. The inside of the buildings is still warmer than the outside ground temp. I seem to recall it is winter there. Here is a lovely grayscale photo of myself converted to color with a a typical thermal image look up scale. Do I have "hot" hair?

 

[|Fred]

Anyone care to venture a guess as to what they could have found?

From what I read this morning (GMT) they found 3 iodine isotopes and 2 cesium isotopes.

I do not recall all the numbers but it wrote the most significant one
Iodine131 up to 1500 Bq/l
Cesium137 up to 18 Bq/l

 

[TCups]

Also interesting to see that no 1 has hotspots at each side of the concreteplug, just where those gates are between the pools, and the drywell head...

Perhaps the gates are solid steel and have greater thermal conductivity than concrete? Don't know what it means for sure.

 

[Reno Deano]

Great question! I want to know the readings above and within the reactors. I pulled this from NHK. My follow up question is what are the other 4 materials found? They keep quoting Iodine131 levels but never mention the other materials made by fission.
Anyone care to venture a guess as to what they could have found?

http://www3.nhk.or.jp/daily/english/21_22.html
5 radioactive materials detected
Tokyo Electric Power Company says some of the nuclear fuel at the Fukushima Daiichi nuclear power plant has apparently been damaged, as higher levels of radioactive materials have been detected in the vicinity.

The utility on Monday released the results of a radiation survey carried out at the plant on Saturday.

Officials detected in the air 5 radioactive materials that are generated by nuclear fission.

The level of iodine 131 was 5.9 milibecquerels per cubic centimeter. That's about 6 times the permissible level for workers without protective masks.

The density of the other substances was also higher than usual, but within safety standards.

The utility says the radiation is likely to have come from the damaged reactors, and added that it will check radiation levels daily.

The company also says it has no plan to halt efforts to restore power and pour water into reactors, as these activities pose no risk to workers as long as they wear protective masks.
Monday, March 21, 2011 19:35 +0900 (JST)

One note: 5.9 milliBq/cm3 is not over any limit. Even if it was 5.9KBq/cm3 it would be be the Occupational DAC (10 CFR 20, Appendix B) limit of 7.4E3 Bq/cm3. Hope my conversions are correct!