Japan Earthquake: Nuclear Plants at Fukushima Daiichi

AI Thread Summary
The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #2,701
TCups said:
Thanks again to tsustuji @post # 2680 for the IR images provided
https://www.physicsforums.com/showpost.php?p=3227707&postcount=2680

Yes, I am sure tsustuji san is interested in a bit more what Tepco and his government tell him.

There are more, I combined the history in three pdf files

when analysing, please be careful of reflected heat by the sun and on some images one can see the shadows of the buildings in the morning sun

To translate just select Japanese text and paste into translate.google.com

on more file for the 20th in the next post
 

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Engineering news on Phys.org
  • #2,702
in continuation thermal image for the 20th march
 

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  • #2,703
Is the fuel crane normally located in the top floor of the Unit ? In Unit 4 pics it is sitting on floor of second floor of blow out from top . Would this position be the bottom of spent fuel pool ?
 

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  • #2,704
TCups said:
ADDENDUM:
Correction of initial error of interpretation on my part - the "ground activity is not from heat sources on the ground. There is a perspective error. The heat sources labeled "ground activity are from lower levels of the building. Also, remember, these images are in the IR spectrum, presumably, not the X-ray or gamma ray spectrum.

Look at attached image - you can see the shadow of the morning sun, so ground activity are sun reflecting of the side walls and other objects on the ground. this image from 30 march
 

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  • #2,705
TCups said:
NEW THERMAL IMAGE ANALYSIS, UNIT 4

Thanks for the new images, tsutsuji @ post # 2680

https://www.physicsforums.com/showpost.php?p=3227707&postcount=2680

Here are new thermal images (at least to me) of Bldg. 4. I presume the "hot" area to the right of the SFP is the open core of the reactor with residual radioactivity, and I hope this is normal.

Without,

http://i306.photobucket.com/albums/nn270/tcups/Picture41.png

and with my annotations.

http://i306.photobucket.com/albums/nn270/tcups/Picture42.png

ADDENDUM:
Correction of initial error of interpretation on my part - the "ground activity is not from heat sources on the ground. There is a perspective error. The heat sources labeled "ground activity are from lower levels of the building. Also, remember, these images are in the IR spectrum, presumably, not the X-ray or gamma ray spectrum.
{open core of the reactor with residual radioactivity, and I hope this is normal.} I think the heat seen here is from fuel rods that where reported to have been blown out during explosion at Unit 4 . They reported that fuel rods where scattered in Unit 4.
 
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  • #2,706
AntonL said:
Look at attached image - you can see the shadow of the morning sun, so ground activity are sun reflecting of the side walls and other objects on the ground. this image from 30 march
Ground heat will not show like that on a thermal camera . There is something there more than normal ground heat . They have reported that fuel rods in Unit 4 where scattered during explosion .
 
  • #2,707
shogun338 said:
Ground heat will not show like that on a thermal camera . There is something there more than normal ground heat . They have reported that fuel rods in Unit 4 where scattered during explosion .

Browse through the the pdf files in https://www.physicsforums.com/showpost.php?p=3228130&postcount=2716" and you will see exactly areas that are illuminated by the sun and areas in shadows and on cloudy days these areas are absent.

However, I agree to you there are heat sources on the roof of unit 4 that do not tie in with the SFP
 
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  • #2,708
AntonL said:
Look at attached image - you can see the shadow of the morning sun, so ground activity are sun reflecting of the side walls and other objects on the ground. this image from 30 march

Upper arrow is pointing to where a gray mass was in a pic I posted . Showing a lot of heat there .
 
  • #2,709
This image of 29th March shows clearly area illuminated by sun, the shaddow unit 4 casts

But the the roof of unit4 has heat outside the SPF
 

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  • #2,710
shogun338 said:
{open core of the reactor with residual radioactivity, and I hope this is normal.} I think the heat seen here is from fuel rods that where reported to have been blown out during explosion at Unit 4 . They reported that fuel rods where scattered in Unit 4.

Can you cite the source of the report of fuel rods scattered in unit 4, please. Thanks.
 
  • #2,711
If Unit 3's massive explosion didn't weaken Unit 4 then Unit 4 must have been so preloaded with hydrogen that when it did explode it ballooned the roof and pulled the four corners inward (at least two of them). The panels blew out like designed but the super structure was forced up and inward.
 
  • #2,712
May i ask what exactly it is we can ascertain from these IR images?
 
  • #2,713
Jorge Stolfi said:
Re the damage of #4 and the piece of debris stuck into the roof:

Its part of the roof of Unit 4 that fell back down after explosion .​

Thanks, it makes sense. Presumably the roof was a concrete or tarmac sheet laid on top of the metal framework, that was lifted off by the explosion without damaging the latter.

But now that the "shot by reactor #3" theory is busted, I am left wondering at puzzling features of the damage on #4:

  1. The concrete walls of the upper floor, on the West and East sides, seem to have been pushed INWARDS against the concrete columns.
  2. The same concrete shell on the North side (facing #3) was peeled off the concrete columns but kept hanging from the top.
  3. The top edge of the North wall was bent INWARDS, whike the first horizontal concrete beam just below it was bent outwards.
  4. While that beam was damaged, the much weaker outre shell remained mostly in place.

Could go on, buy you get the idea.

Perhaps there was an explosion BELOW the topmost floor, and that created overpressure on the OUTSIDE of the walls of the top floor, pushing them in?

Unit 3 exploded on March 14th, 11:15am. There was an explosion at unit 4 on March 15th, ~6:00am that blew out two wall panels. This damage was shown in helicopter flyovers. There were attempts to spray water into the pool at this time I believe and two instances of fire were noted. Some time after this there must have been at least one more (larger) explosion to leave the building in it's current state. You can see blast driven debris trails and damage that exited from both units 3 (very obvious) and 4 (less obvious) in the hi-res aerial photos.
 
  • #2,714
Jorge Stolfi said:
I have plotted the data from the NISA/METI press relases:

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

Hope it helps. All the best, --stolfi

Great stuff - thank you very much.

What I wonder about, is that drywell is pretty radiating in all 3, and in #1 the Torus is also quite hot.

Why is the Torus so active in #1 but not in #2 and #3?
 
  • #2,716
I want to clarify something with the IR images, although some might seem to show ground activity, that's mostly due to the variation in the measured temperature range, when the same color spectrum is used (rainbow in this case). So in one picture, green might correspond to 15deg, but in another to 30deg. Keeping that in mind, I don't see anything anomalous on the ground apart from slightly shiny objects (in the IR range). Another point is, because there is steam over the SFP's, the temperature readings will be affected (show lower values).
 
  • #2,717
Photos of the infamous "leak in the pit" from the METI press release 71 (2011-04-03-15:30) :http://www.meti.go.jp/press/2011/04/20110403002/20110403002-4.pdf"
 
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  • #2,718
This http://www.whas11.com/home/Hopes-new-power-line-may-ease-Japan-nuclear-crisis-118105609.html" has the US claiming Unit 4 pool is dry. Company says no. This post has a slightly different picture of Unit 4 with no steam showing at all after the blast with the poster's own speculations.
 
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  • #2,719
razzz said:
This http://www.whas11.com/home/Hopes-new-power-line-may-ease-Japan-nuclear-crisis-118105609.html" has the US claiming Unit 4 pool is dry. Company says no. This post has a slightly different picture of Unit 4 with no steam showing at all after the blast with the poster's own speculations.

That is from 16 march - nearly 3 weeks old!
 
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  • #2,720
orndorf said:
May i ask what exactly it is we can ascertain from these IR images?
Extreme heat radiating from that particular area that only nuclear decay could cause. Hopefully the area is surrounded by water as it cools down.
 
  • #2,721
I_P said:
Unit 3 exploded on March 14th, 11:15am. There was an explosion at unit 4 on March 15th, ~6:00am that blew out two wall panels. This damage was shown in helicopter flyovers.

Do you mean the two central panels on the North and South walls (3rd row from top)? Then the explosion was below the upper floor, right?

Or perhaps you mean two panels on the South wall, near the SE corner? (That is where the Green Machine can be seen, and some reports claim that the SFP is just below it.)

I_P said:
Some time after this there must have been at least one more (larger) explosion to leave the building in it's current state.

That is interesting. I haven't seen anyone mention a second explosion at #4.
 
  • #2,722
razzz said:
For reference, Wikipedia has a decent time lines and overall information combined together.

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

...

I looking for more details for the first hours and days.
When did the diesel generators fail? When did the batteries run out of power? When stopped the emergency cooling for each unit? When exactly did they start venting? etc. etc.

Some of that information (eg. about the diesel generators) is in the Japanese Wiki (try to translate by google)
http://ja.wikipedia.org/wiki/%E7%A6%8F%E5%B3%B6%E7%AC%AC%E4%B8%80%E5%8E%9F%E5%AD%90%E5%8A%9B%E7%99%BA%E9%9B%BB%E6%89%80%E4%BA%8B%E6%95%85%E3%81%AE%E7%B5%8C%E7%B7%AF"




Other information is still missing (batteries).

For me it is not clear what happened, especially whether the engineers always did the right things at the right times.
 
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  • #2,723
AntonL said:
That is from 16 march - nearly 3 weeks old!

I know that but the question is, who do you believe? Pools are dry and an explosion spreads fuel everywhere or fuel partially exposed with 'normal' hydrogen explosion.

It was a no win either way for if the pool was empty for any length of time and refilled by chopper or hose, then they had to create a blast by adding water on hot fuel rods. Low water in the pool, smaller explosion happens anyway.
 
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  • #2,724
Thank you for the IR image btw , we now have evidence that the concrete slab on unit 3 is gone
 
  • #2,725
ohohohoh said:
I looking for more details for the first hours and days.
When did the diesel generators fail? When did the batteries run out of power? When stopped the emergency cooling for each unit? When exactly did they start venting? etc. etc.

Other information is still missing (batteries).

For me it is not clear what happened, especially whether the engineers always did the right things at the right times.

Browse thishttp://www.docstoc.com/docs/7522336...m=email&utm_campaign=109121477&utm_content=3"
 
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  • #2,726
Jorge Stolfi said:
Do you mean the two central panels on the North and South walls (3rd row from top)? Then the explosion was below the upper floor, right?

Or perhaps you mean two panels on the South wall, near the SE corner? (That is where the Green Machine can be seen, and some reports claim that the SFP is just below it.)



That is interesting. I haven't seen anyone mention a second explosion at #4.

I believe it was the SE corner by the pool (first explosion). I have never seen documentation of other explosions - except the unmistakable evidence in the current aerial photos. I find this puzzling. It must have occurred at night, but the onsite workers must have heard it. Like the spike in offsite radiation on the 21st - clear evidence of serious change but no official explanation or mention. Adds to the sense that much more is known and suspected than has been publicly discussed.
 
  • #2,727
Bodge said:
"Tellurium 129 Presence Is Proof Of Inadvertent Recriticality At Fukushima"

That's the latest claim from Gunderson, via http://www.zerohedge.com/article/tellurium-129-presence-proof-inadvertent-recriticality-fukushima"

It has a 70 minute half life. Data collected 30.03.11

http://www.tepco.co.jp/en/press/corp-com/release/11033110-e.html

There is also a metastable isomer of this isotope, see http://nucleardata.nuclear.lu.se/nucleardata/toi/nuclide.asp?iZA=520429

It has a half-life of 33.6 days, and most of it (63 %) decays to the ground state by emitting a gamma. So the ground state is expected to be in the spectra. In steady state ("equilibrium"), it should be in the data with 63 % of the activity of the metastable isomer.

Its presence does not prove any recent criticality. It does not even point to recent criticality.
 
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  • #2,728
Does anyone know where the vent from the drywell into upper containment should be? Or the vent for the wetwell? Could these vents which I understand fail open be the source of the steam.

I also wonder why the water pouring into the ocean via the crack isn't steaming hot. If the feed water temperatures are correct the water temperature exiting that crack should be close to boiling. Large amounts of water vapor should be visible especially with the low ambient temperatures.. I don't see it. I see relatively cold water being injected into the channel.

I think the drywell and wetwell are completely flooded in reactor 2 except for an ullage space and at a lower temperature then the sensors are reporting. Steam in an intact reactor vessel is venting into the wetwell and the water level is balanced by the steam pressure and the water injection pressure. Steam is going up the vent and colder injected water is exiting another path.
 
  • #2,730
TEPCO does not know where the contaminated water comes from:

http://www.saposjoint.net/Forum/viewtopic.php?f=66&t=2657&p=31585#p31585"

Tokyo Electric Power Co. used colored powder Monday to trace the source of highly radioactive water leaking into the sea near the troubled Fukushima Daiichi nuclear power plant, while mulling the use of silt-barriers in the sea to prevent the further spread of radiation.

The plant operator poured 13 kilograms of the powder into an underground trench to find the point from where radioactive water is leaking into the Pacific Ocean in front of the plant, after its attempt to block the leakage from a cracked seaside pit connected to the No. 2 reactor turbine building showed no effect so far.

Radioactive water has been filling up the basement of the No. 2 reactor turbine building and the tunnel-like trench connected to it. The powder was injected into the trench shortly after 7 a.m. but did not come out from the crack as of 11 a.m., according to the company officials.
 
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  • #2,732
Based on an earlier post and the generic GE BWR reactor manual, here is my uderstanding of how the water level measurements are taken:

There are two or more water-filled tubes that extend fom some accessible location into the core, through the bottom of the RPV. One tube ends well above the normal water level, the other(s) end(s) somewhere between the core shroud and the RPV wall, below the shroud's upper edge. The difference in pressure between the two tubes is interpreted as the water level.

The same post warned that what is being measured is actually the water level between the shroud and the RPV wall, which, given the current situation, may not be the water level in the core proper.

Is this correct?

Another question: since the crisis days, the water levels have been quite stable (#2's level barely budged when the pumping rate was doubled) and well below the top of the fuel (1.7, 1.5, and 2.3 meters in #1-#3). Why and why?
 
  • #2,733
  • #2,734
Cire said:
Does anyone know where the vent from the drywell into upper containment should be?

I would also like to know where are those vent (the one venting from the primary containment (drywell )to the segondary ) are
 
  • #2,735
If the RPV was breached and the DW is leaking a large amount of water then DW/RPV water will only maintain at the leak point level.

BWR_Mark_I_Containment_sketch_with_downcomers.png


Rough sketch of a typical Boiling water reactor (BWR) Mark I Concrete Containment with Steel Torus including downcomers, as used in the BWR/1, BWR/2, BWR/3 and some BWR/4 model reactors.

* DW = Drywell
* WW = Wetwell
* SFP = Spent Fuel Pool
* RPV = Reactor Pressure Vessel
* SCSW = Secondary Concrete Shield Wall
 
  • #2,736
TCups said:
http://i306.photobucket.com/albums/nn270/tcups/Picture45.png

Unfortunately you got it wrong... and miss read the picture.. your over head crane need to be slided slightly to th right (north)

I'm 80% confident that we are seeing a round heat emitter bellow the crane, the round shape is the one of the Concrete stab or to be exact the lack of...
 
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  • #2,737
342px-Bwr-rpv.svg.png


Have you seen a pic of one these things under construction yet?
 
  • #2,738
Great idea:
NEWS ADVISORY: TEPCO may release 15,000 tons of contaminated water into sea from Tues
 
  • #2,739
attachment.php?attachmentid=33800&d=1301592834.jpg
 
  • #2,740
elektrownik said:
Great idea:
It's all they can do. Must keep cooling down the hot spots. first and foremost.
 
  • #2,741
razzz said:
Browse thishttp://www.docstoc.com/docs/7522336...m=email&utm_campaign=109121477&utm_content=3"

Ok, that's the Areva PowerPoint.
At Page 12 the are data for the Batteries for two Units.
Unit 1 runs out of Batteries on 11. at 16:36 ! Much less then the 8 hours battery capacity!
And at Unit 3 they reached march 13. at 2:44! Much much more than the 8 hours.
And there is no source mentioned for their data!

Sorry, I'm not necessarily believing that!
 
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  • #2,742
ohohohoh said:
Ok, that's the Areva PowerPoint.
At Page 12 the are data for the Batteries for two Units.
Unit 1 runs out of Batteries on 11. at 16:36 ! Much less then the 8 hours battery capacity!
And at Unit 3 they reached march 13. at 2:44! Much much more than the 8 hours.
And there is no source mentioned for their data!

Sorry, I'm not necessarily believing that!

Wait until you read how long they were without water.
 
  • #2,743
Tepco to release 11500 tons of radioactive water into Pacific Ocean . To make room for all the water coming out of damaged reactors . Just announced on CNN LIVE .
 
  • #2,744
3500 tons less than half an hour ago ? at this rate they won't be releasing anything at the end of the day.. (excuse the sarcasm targeting the way the press takes liberty with numbers..)
 
  • #2,745
[PLAIN]http://img856.imageshack.us/img856/7640/capturevi.jpg
Why it is so hot at the right side ? There is no core or SFP...
Look at 00:30 this is reactor 1.
http://www.liveleak.com/view?i=694_1301894964UPDATE: new temp data: http://www.mod.go.jp/j/approach/defense/saigai/tohokuoki/kanren/230404.pdf
 
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  • #2,746
razzz said:
attachment.php?attachmentid=33800&d=1301592834.jpg
Maybe they could use this monster to pick that up and drop it in a giant cooling pool . Just a thought . LOL
 

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  • #2,747
razzz said:
Wait until you read how long they were without water.

Do you mean the data on page 19?
 
  • #2,748
elektrownik said:
[PLAIN]http://img856.imageshack.us/img856/7640/capturevi.jpg
Why it is so hot at the right side ? There is no core or SFP...
Look at 00:30 this is reactor 1.
According to the paper hot is between 10 and 16° .. not so hot..
I'm thinking that the reinforced top structure of unit 3 , 4 and 2 might have been a bad idea..
 
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  • #2,749
CORRECTED THERMAL IMAGE BLDG 3 -- OVERHEAD CRANE'S POSITION CHANGED


Per Fred's observations:

|Fred said:
Unfortunately you (TCups) got it wrong... and miss read the picture.. your over head crane need to be slided slightly to th right (north)

I'm 80% confident that we are seeing a round heat emitter bellow the crane, the round shape is the one of the Concrete stab or to be exact the lack of...

If the plug is gone, then it is indeed unfortunate. I stand corrected on the position of the crane, Fred. And I can see heat leaks around the edges, yes, but do you really think the entire concrete plug is gone? Where? For that to be the case, wouldn't the greatest visible damage to Bldg 3 have to be in the center of the building? Or did the plug hit the underside of the crane and fragment? Or did the plug blast free and then an intact section of roof girders and the crane fall back into place over the open mouth of the reactor's primary containment?

http://i306.photobucket.com/albums/nn270/tcups/Picture47.png
 
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  • #2,750
razzz said:
If the RPV was breached and the DW is leaking a large amount of water then DW/RPV water will only maintain at the leak point level.

Not quite. This is true only if there is no water added to the RPV or DW.

If water is added at a constant flow rate to the RPV, the water in the RPV will find a level such that leakage balances additions (i.e. until it is in steady state), where "leakage" can be interpreted to mean all losses including by steam. Obviously if the leak is large then more water is required to maintain the required water level.
 

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