Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[TCups]

What were they trying to do in unit #4 before it exploded/burned and after #3 exploded? In this picture, #3 has exploded, #4 has not, but I do not see the truck halfway into the access bay where they load/unload fuel and other supplies for the building:

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi_march14_2011_dg.jpg

Am I missing it? The truck is clearly visible in all subsequent overhead pictures of #4 after it burned/exploded:

http://cryptome.org/eyeball/daiichi-npp/pict12.jpg

Also I wish people would abandon the idea that there is any good data in the soundtrack of the video of #3 exploding that has the 3 added (and heavily processed) explosion sounds -- it's clearly faked (for many reasons previously stated here). Here's another one with faked added sound:

Here is a "guess" about the truck:

If the truck had been parked out back, and if it was contaminated from radioactive waste and needed to be cleared from the roadway behind the building (as in subsequent pictures), then perhaps the quick solution was to back it into the concrete tunnel, out of the way.

While it is likely that the sound track was indeed re-synched to the video for broadcast purposes, I doubt that anyone went to great lengths to "fake" what was originally on the sound track before it was synched to the video. Do you have any strong evidence to the contrary?

 

[clancy688]

My best guess is that the buiding explosions came from the containments of units 1, 2, and 3. and that includes the damage to unit 4.

That's my best guess, too. But sat images show, that there was no further damage to any of the other reactors during the time when Unit 4 was destroyed.

On one picture it's still fine and on the next one it's a pile of rubble. But Unit 1, 2 and 3 didn't change the slightest on these two images... and there's no additional rubble on the surrounding buildings. Even the rubble from the Unit 3 explosion didn't change its position.

 

[artax]

don't know if the whole of this vid has been posted before?

 

[Jorge Stolfi]

Boiling doesn't mater. CsI may get attached to droplets carried off with steam but most will remain in the water.

Just because you have Cs and I in the water, it does not mean that they will stick together as CsI. Each ion (Cs⁺ and I^-) will go is way and interact with all the other crud in the pool.

The use of seawater to keep the pools full should prevent acidic conditions in the pool.

Fresh seawater is slightly alkaline, but boric acid was added to it. It is a weak acid, but presumably enough to allow the much smaller amount of iodide to form HI and leave with the steam.

However it seems that iodide in water easily reacts with oxygen to form neutral iodine I2, which is volatile too. The pH does not seem to matter in this case.

On the other hand cesium has no volatile compounds that I know of, so it can only leave the liquid carried by droplets, as you say --- which will only form if the water if boiling or blasted away.

In summary, if hot water containing Cs and I is kept in an open container (like the #4 SFP, but unlike a normal reactor), I guess that the Cs:I ratio will gradually get skewed towards the former. Would that effect be enough to confuse the interpretation of the analysis, e.g. with regard to old x recent fission?

If operators were able to get close enough to the pool to take a sample it must be well short of boiling.

They took the sample with a bucket suspended from the concrete pump by a cable. The camera was mounted on the crane too. Radiation presumably was a bigger obstacle to human intervention than any heat level would be.

 

[artax]

image stabilised t-hawk video?

 

[TCups]

That's my best guess, too. But sat images show, that there was no further damage to any of the other reactors during the time when Unit 4 was destroyed.

On one picture it's still fine and on the next one it's a pile of rubble. But Unit 1, 2 and 3 didn't change the slightest on these two images... and there's no additional rubble on the surrounding buildings. Even the rubble from the Unit 3 explosion didn't change its position.

I'm sorry - I don't follow what you are saying.

Are you saying that all the damage to Bldg 4 came from explosions of the other buildings?
Are you saying that the blast in Building 4 came from the primary containment of Unit 4 or from the primary containment of the other buildings?
Are you saying that all of the rubble outside of Bldg 4 including the collateral damage to the adjacent Turbine Bldg and pipes was there before Bldg 4 exploded?

IMO, Bldg 4's explosion was and event independent of any of the other explosions, and the only likely etiology for the explosion was hydrogen or steam or both coming from SFP4.

Do you think something other than that?

 

[Jorge Stolfi]

I think as long as the RPV has water on outside, fuel (non-critical) can only partially melt through. Of course afterwards, stupid operator actions (e.g. raising the pressure) can blow it out.

Suppose the outer stainless steel is at temperature 100 Celsius, the inner stainless steel at 1300 Celsius (almost molten), and the thickness is 23cm. The temperature gradient is 1200/0.23=5200 K/m , and the heat flow is 21 W/m*K * 5200 K/m = 21*5200 = about 0.1 MW/m^2 .

However that only works if you can keep liquid water in contact with the steel. If the heat flow is too high, a layer of steam will form between the two, and the steel then can heat up to any temperature.

Also there need not be a continuous gradient in the molten fuel.

 

[Bodge]

yes and the thermal conductivity of the fuel lava is a lot lower than thermal conductivity of steel.
http://www.lenntech.com/stainless-steel-304.htm
thermal conductivity at 500 celsius = 21 W/m*K

http://www.ati.ac.at/fileadmin/files/research_areas/ssnm/nmkt/06_BWR.pdf
the wall at bottom of rpv is reported as 23 centimetres.

I think as long as the RPV has water on outside, fuel (non-critical) can only partially melt through. Of course afterwards, stupid operator actions (e.g. raising the pressure) can blow it out.
Suppose the outer stainless steel is at temperature 100 Celsius, the inner stainless steel at 1300 Celsius (almost molten), and the thickness is 23cm. The temperature gradient is 1200/0.23=5200 K/m , and the heat flow is 21 W/m*K * 5200 K/m = 21*5200 = about 0.1 MW/m^2 .
Now on to thermal conductivity of uranium dioxide
http://en.wikipedia.org/wiki/File:ZrUthermalcond.png
around 4 W/m*K meaning that for same heat flow it has 5x the thermal gradient of stainless steel = meaning that thermal gradient through first 12 centimetres of fuel will be 2.5*1200 = 3000 kelvin or so. From the orders of magnitude alone it is obvious that fuel cooled from the bottom (no convection) will be literally boiling off inside before it can melt through RPV.

Thus the worst case scenario of reactor accident: the RPV is cooled from outside, a little water is getting into RPV, the steam (with literally fuel aerosol in it) is vented out, plus the people in charge are measuring just the I and Cs and telling all the time how it is getting better and putting stress on comfort words such as containment and intact.
I really hope that did not happen. This sort of fuel vaporization might make you wish it just melted down and vent all over the place due to steam explosion, rather than cooked itself silently.

The awesome thing about decay heat is that it doesn't care how hot the fuel already got. It will just keep heating itself, and a lump of fuel in a pot can literally boil itself off and re-condense as fine aerosol.

Can anyone else confirm this hypothesis?

 

[tsutsuji]

110325-F-XC395-111 by Official U.S. Air Force : "Japan Ground Self Defense Force members measure a water pump at Yokota Air Base Japan that will be employed at the Fukushima Daiichi Nuclear Power Plant March 25, 2011 during Operation Tomodachi. "

110325-F-XC395-049 by Official U.S. Air Force : "Pipe flange fittings sit at Yokota Air Base, Japan March 25, 2011 waiting to be assembled for a water pumping station that will be employed at the Fukushima Daiichi Nuclear Power Plant during Operation Tomodachi. The Tokyo Electrical Power Company is adding an additional water pumping station to pump fresh water instead of seawater to cool the reactors at the damaged nuclear power facility with the help of the U.S. government and various other agencies."

110325-F-XC395-091 by Official U.S. Air Force : "Blair Smith, a field service manger with Resource Equipment LTD, teaches a Japanese worker how to assemble pipe flange fittings at Yokota Air Base, Japan March 25, 2011 for a water pumping station that will be employed at the Fukushima Daiichi Nuclear Power Plant during Operation Tomodachi. "

110325-F-IF940-027 by Official U.S. Air Force : Airman 1st Class Jeremy Hamblin, 374th Maintenance Squadron metals technician, grinds on a sheet of metal that will be used to make a flange here March 26. After completed, Australian engineers will pass them to Japanese relief workers who can use the newly created flanges to help cool down the nuclear reactors and help stabilize the nuclear power plant in Japan"

Yokota Airmen accomplished custom made parts for Fukushima power plant : "Airman 1st Class Jeremy Hamblin, 374th Maintenance Squadron, delivers a component parts for a water pump at Yokota Air Base, March 27, 2011 after working for it 20 hours. These components will be delivering to Australian engineers that pass them to Japanese relief workers who can use the newly created flanges to help cool down the nuclear reactors and help stabilize the Fukushima Daiichi nuclear power plant."

 

[Rive]

OK, then if it's the basement where the torus is, where is the torus on the picture?

On the picture there is a model of Toshiba ABWR: http://www.newcs.futaba.fukushima.jp/05-20000519/f1-03.JPG
On the wall there are drawings of GE MKII and an ABWR containments - none of them related to Fukushima I Unit 3.

The would be U7 and U8 of Fukushima I were planned ABWRs.

Here is a detailed view of an ABWR installation: http://www.sargentlundy.com/images/ToshibaABWR-300dpi.jpg

Containment types: http://m.blog.hu/nu/nukleraj/image/flegman/jap_bwr_kont.png

The debated drawing: http://www.newcs.futaba.fukushima.jp/05-20000519/f1-13.JPG

It's not an exact match but it fits with the ABWR: and does not fits with the MK1 containment or with the aerial view of Unit3. That's what I see. Of course I can be wrong.

 

[NUCENG]

Thanks for the reminder. I often forget how big the numbers are we're using here... ^^;

I tried to calculate it myself and got a similar outcome. But could you please do me a favor... please use SI-units and not feet / curie... :(

It's so hard to think in these units, and since official releases are all in SI, I think we should use them, too.




Uh, so when the Tsunami hit there were around 2E16 Bq in all (used core) fuel assemblies? Where can I find this calculation?

My American upbringing and work experience were showing, yes?? I though getting the result into Bq/cm<sup>3 was doing good, but I'll try to work my way into the 21st century.

I have been extracting information from a list of activation products, actinides, and fission products for BWRs using ORIGEN2. The analysis was based on bounding conditions of fuel enrichment, burnup, and avearage bundle power. Results are expressed in curies per megawatt for radioactive isotopes and in grams per megawatt for all isotopes of significance (about 600 are listed). NUREG-1465 contains references to a number of additional studies that include "typical" or even some plant specific source term lists.</sup>

 

[NUCENG]

That's my best guess, too. But sat images show, that there was no further damage to any of the other reactors during the time when Unit 4 was destroyed.

On one picture it's still fine and on the next one it's a pile of rubble. But Unit 1, 2 and 3 didn't change the slightest on these two images... and there's no additional rubble on the surrounding buildings. Even the rubble from the Unit 3 explosion didn't change its position.

I agree with everything you say but if you eliminate hydrogen from SFP4 what is left? However improbable, and to date unproveable, it had to come from an external explosion. The initial report of the explosion talked of "an explosion inside the facility" and then they found damage to unit 4. It doesn't sound to me like they knew for certain that the explosion was inside unit 4. Your guess is as good as mine.

 

[StrangeBeauty]

While it is likely that the sound track was indeed re-synched to the video for broadcast purposes, I doubt that anyone went to great lengths to "fake" what was originally on the sound track before it was synched to the video. Do you have any strong evidence to the contrary?

With respect, your statement shows a lack of healthy scientific skeptism. Others have asked for the source of the original video with sound -- I have seen none. Evidence should be under suspicion until proven reliable.

As to evidence that this is faked:
1) The explosion video appeared first without sound. I originally saw this on BBC with no sound.
2) The sound is mis-synced by a completely wrong amount. The camera was miles away and the sound should have been delayed by 10+ seconds (2 miles -- probably much more).
3) The sound has way too many high frequencies for the distance. Think about what thunder sounds like close up, versus far away.
4) The second explosion sound is louder than the first even though no evidence of a greater explosion is seen on the video. The third explosion sound is also louder. Just look at it in any sound editing tool (e.g. audacity)
5) There is nothing visible corresponding to the third explosion (or the second)
6) "news" organizations often juice things up to make it more sensational. See the second video with completely different sound track in my previous post.
7) This sort of sound replacement is simple to add later. 5-10 minutes work at most.
8) To my ear, the three explosions are actually the same explosion sound source with slightly different processing.

fyi I have a background in professional sound production (amongst other things).

 

[NUCENG]

Just because you have Cs and I in the water, it does not mean that they will stick together as CsI. Each ion (Cs⁺ and I^-) will go is way and interact with all the other crud in the pool.

Fresh seawater is slightly alkaline, but boric acid was added to it. It is a weak acid, but presumably enough to allow the much smaller amount of iodide to form HI and leave with the steam.

However it seems that iodide in water easily reacts with oxygen to form neutral iodine I2, which is volatile too. The pH does not seem to matter in this case.

On the other hand cesium has no volatile compounds that I know of, so it can only leave the liquid carried by droplets, as you say --- which will only form if the water if boiling or blasted away.

In summary, if hot water containing Cs and I is kept in an open container (like the #4 SFP, but unlike a normal reactor), I guess that the Cs:I ratio will gradually get skewed towards the former. Would that effect be enough to confuse the interpretation of the analysis, e.g. with regard to old x recent fission?


They took the sample with a bucket suspended from the concrete pump by a cable. The camera was mounted on the crane too. Radiation presumably was a bigger obstacle to human intervention than any heat level would be.

NUREG-1465 "Accident Source Terms for Light-Water Nuclear Power Plants" estimates that 95% of Iodine is released as CsI. Both of these elements are highly reactive and what would be more likely to form than two highly reactive ions of opposite polarity? That is one of the most significant changes from the days of TID-14844, the previous basis for analyzing source terms. I would also refer you to NUREG/CR-5950" Iodine Evolution and pH Contro"l , NUREG/CR5732 "Iodine Chemical Forms in LWR Severe Accidents" , and there are other discussions of Cesium Transport.

Search at http://www.scienceaccelerator.gov/

By the way Cs in water produces CsOH a strong base. Eventually formation of carbonic acid from CO2 in the atmosphere may take the pool water acidic, but we will see gradually rising atmospheric Iodine when that happens. I haven't seen it yet.

 

[Dmytry]

re: sounds, I'm not an audio effects person but I do not think it sounds right. I think it sounds too much artificial/dramatic plus it repeats the same sound (which video are we talking about exactly?). Pauses are too good, too good composition.
My first thought was that someone just added generic clap clap for soundtrack, being dissatisfied with lack of soundtrack. I never even considered possibility it was real before coming across this thread.

In a previous post (#4111) I calculated the concentration of a 5% gap release of Iodine-131 into the pool from just the last core offloaded. Unfortunately I only accounted for a 30 day decay. Mr. Gunderson correctly indicated that the unit was shutdown 4 months before the accident. It has been a month since. So I repeated my calculation accounting for 180 days (6 months) of decay.

From an ORIGEN2 calculation of a BWR the core inventory of I-131 at 6months after shutdown is 5.03E-3 Ci per MW. Assuming 760 MW Electric and a 33% efficiency for Unit 4 leaves a total I-131 at the time of the accident of 5.23E5 Ci. In Taking 5% (gap release) and converting to Bq leaves 9.67E14 Bq.

I assumed a Fuel Pool of 40' by 20' by 40' deep. That converts to 1.81E9 cm^3.

Possible concentratiion of I-131 after 6 months in the fuel pool with only 5% of the source term released is up to 5.34E5 Bq/cm^3.

Personally I think Mr. Gunderson is absolutely correct when he ridicules TEPCO's explanation of Iodine deposition. But you do not need criticality to explain the concentration of I-131 they reported.

I try to keep reminding people that just because an isotope has a short half life does not mean it disappears in a few half lives. Half of a big number is still a big number. I-131 will likely be detectable beyond a year after shutdown.

except that the problem is if that iodine came from 6-month old fuel, along with it totally insane Bq of Cs-137 would of came as well.

 

[Krikkosnack]

(sigh)

Didn't happen. These are not the droids you are looking for. Move on.

no comments...

Look closely at the horizontal debris tracks, the impacts on the front and rear facades of the turbine buildings, the horizontal debris tracks on the west side of the buildings, the damage to the buildings on the west side of the reactors, and the pieces of the wall slabs still laying about on the photographs. ALL of that came from horizontal outward blast of the wall panels. None of the wall panels went upward.

It's True... i never said "no"

The only good candidates for vertical "ballistic" objects, IMO, were the FHM directly over SFP3 (now disproved)

Please, let me be in disagree with you. Why we have that the explosion of the reactor 3 is VERY different from reactor 1?
As i said, looking at the video, the explosion seems to be splitted in two phases. First fase the detonation upon or near the SFP3 ( of Inflammable material...) that involves all that we said ( even the FHM) . Second phase with one " smoothed detonation or a big overpressure", maybe the second "fake bang", (inflammable material or not, i don't know ) that shot into the air some objects like a cannonball.

and portions of the buildings roofs (which seems a likely scenario at least for now).

I don't think only the roof, but i can't say what i can't prove...

Go way back to around to posts in the low #600's a few weeks ago and you will find lots of pictures and analysis.

i was there... reading all the "hypothesis"

 

[Dmytry]

if we're discussing sounds in this:
http://www.youtube.com/watch?v=T_N-wNFSGyQ&feature=related
I am very nearly 100% sure it is fake. Repeats with same interval.

 

[TCups]

With respect, your statement shows a lack of healthy scientific skeptism. Others have asked for the source of the original video with sound -- I have seen none. Evidence should be under suspicion until proven reliable.

As to evidence that this is faked:
1) The explosion video appeared first without sound. I originally saw this on BBC with no sound.
(OK, so?)

2) The sound is mis-synced by a completely wrong amount. The camera was miles away and the sound should have been delayed by 10+ seconds (2 miles -- probably much more).
(I believe the speed of sound in air at sea level is 343.2 m/s, so 10 seconds would br 3.43 K or 2.1 miles, probably not much more)

3) The sound has way too many high frequencies for the distance. Think about what thunder sounds like close up, versus far away.
(the attenuation over distance would be log-rhythmic if my rudimentary understanding of dB is correct, and the "amount" would be dependent on the absolute amplitude of the initial sound, frequency, and the sensitivity of the recording device, and perhaps the graphic equalization used on the playback audio. Accentuation of the higher frequencies on replay ≠ "fake")

4) The second explosion sound is louder than the first even though no evidence of a greater explosion is seen on the video. The third explosion sound is also louder. Just look at it in any sound editing tool (e.g. audacity) -- (see attached)

5) There is nothing visible corresponding to the third explosion (or the second)
(sound waves are seldom visible, in my novice experience, but again, I thought I saw two components to the blast -- but as we know, I have been wrong before)

6) "news" organizations often juice things up to make it more sensational. See the second video with completely different sound track in my previous post.
(again, juicing up the audio and adjusting volume and frequency of the playback of a sound track ≠ fake soundtrack. In fact, I believe it is routinely done in forensic analysis.)

7) This sort of sound replacement is simple to add later. 5-10 minutes work at most.
(Are you suggesting they just lifted an explosion sound track from some other audio stock file instead of doing the same work with the un-edited sound track of the actual event? If so, then that of course would be fakery and fraud.)

8) To my ear, the three explosions are actually the same explosion sound source with slightly different processing.
(forget your ear, sir, what does the technical audio processing tell you? You have done the technical audio processing, right?)

fyi I have a background in professional sound production (amongst other things).
(excellent, sir)

Which is the healthier skepticism? Presuming something is a "fake" intended to willfully deceive or presuming until proven otherwise that it is not. Thanks, though for your opinion. Here's a bit more evidence, based on another member who posted here earlier on this very subject -- technical analysis of the sound track. You may or may not have read M. Bachmeir's earlier posts.

Mike summarized his opinion of the sound track in an earlier, private email to me, along with at least 20 different graphics and several re-synched versions. With due respect and credit to Mike, I will quote his email in part:

"in summary, there's evidence the video was cut. There's evidence the audio was adjusted. There's no evidence I can find of clipping, merging, or outright faking. Just bad use of out-of-the-box tools for syncing (in a hurry to get the scoop)."

I know Mike B. spent hours on this, but what the heck . . . Here is a bit of the 20-some-odd files and sound track analysis he has shared with me. But in view of my insufficient scientific healthy skepticism (and the fact I am not sure of anything), I shall respectfully defer to your learned opinion.

PS: the attached file is a screen capture -- don't click the button and expect to get playback. You might PM Mike if you would like a copy.
Regards.

 

[Dmytry]

What exactly video's sound are you guys talking of?

 

[NUCENG]

re: sounds, I'm not an audio effects person but I do not think it sounds right. I think it sounds too much artificial/dramatic plus it repeats the same sound (which video are we talking about exactly?). Pauses are too good, too good composition.
My first thought was that someone just added generic clap clap for soundtrack, being dissatisfied with lack of soundtrack. I never even considered possibility it was real before coming across this thread.


except that the problem is if that iodine came from 6-month old fuel, along with it totally insane Bq of Cs-137 would of came as well.

Correct. It could be up to 1E6 Bq/cm³. Since they dibn't measure anywhere near that it indicates fairly limited damage to fuel in the pool.

 

[TCups]

What exactly video's sound are you guys talking of?

Sorry. I went back but the original video with audio link is no longer working. It is a video of the blast at Unit 3 that has 3 distinct "booms".

 

[Dmytry]

Correct. It could be up to 1E6 Bq/cm³. Since they dibn't measure anywhere near that it indicates fairly limited damage to fuel in the pool.

so what are we left with - the iodine could not have came from the fuel, and it couldn't have came from the aerial deposition (see Gundersen) unless it is much, much worse than Chernobyl already. Hell, with this much deposition they couldn't be able to even work on site.
Then, with re-criticality, it would also have took a LOT of fissions to make this much iodine for it to be released without a lot of Cs-137 left over from reactor operation. The only logical explanation left is that fresh fuel in the spent fuel pool gone critical (with serious amount of fissions) and then got damaged. My understanding is that there's a lot of Cs (ultra-fine aerosol of Cs2O perhaps? and CsI but keep mind there's far more Cs than I) and I in the gasses in the fuel rods.
It would be better if there were I-134 figures also.

To summarize: if we are considering damage to old fuel, Cs-137 indicates far less damage than I-131 , a disagreement . The re-criticality fissioning of old fuel has to be non-negligible comparing to original fissioning of that old fuel in the reactor. I'd guess fresh fuel gone critical and was damaged most extensively, but I dunno, need calculations to conclusively show that. Need upper bounds on how much fissioning could have gone on there without it becoming too obvious.

 

[PietKuip]

NUREG-1465 "Accident Source Terms for Light-Water Nuclear Power Plants" estimates that 95% of Iodine is released as CsI. Both of these elements are highly reactive and what would be more likely to form than two highly reactive ions of opposite polarity? That is one of the most significant changes from the days of TID-14844, the previous basis for analyzing source terms. I would also refer you to NUREG/CR-5950" Iodine Evolution and pH Contro"l , NUREG/CR5732 "Iodine Chemical Forms in LWR Severe Accidents" , and there are other discussions of Cesium Transport.

Search at http://www.scienceaccelerator.gov/

By the way Cs in water produces CsOH a strong base. Eventually formation of carbonic acid from CO2 in the atmosphere may take the pool water acidic, but we will see gradually rising atmospheric Iodine when that happens. I haven't seen it yet.

Hot fuel rods in the open would evaporate CsI-molecules and CsI clusters. But this is very soluble in water. When cooling with seawater (NaCl mostly), it is impossible to distingish between solutions of (CsI + NaCl) and (CsCl + NaI). In water, the Cs+ ions and the I- ions are independent. And not especially reactive.

 

[Dmytry]

on topic of chemistry... in what form would the Cs exist? Wouldn't it take away O from UO2 becoming Cs2O ? Then in water, CsOH ?
Cs is far more reactive than U. I'd expect any Cs to immediately grab the oxygen from UO2

 

[Dmytry]

ahh and by the way, on topic of chemistry, each time U fissions, there's two atoms of oxygen left.

 

[StrangeBeauty]

What exactly video's sound are you guys talking of?

The original video from the BBC without sound that I first viewed:


The same video from Sky News without sound:


Same video from Japanese TV again, without sound:


The oztvwatcher version (who's that?) with sound:


Another video from Indian TV (?guessing here) with completely different sound:


Which ones have been faked? They can't all be the original.

TCups, you may continue on your puzzle hunt, which has often been interesting -- but I'm just trying to keep you from wasting time on bad information. Yes, I'm suggesting fakery/fraud to gain viewers. It was obvious to me from the first time I heard it that was concocted since I've concocted such things myself for various purposes (e.g. foley work). Not only did I think this was concocted, but it was badly done - an obvious fake for the reasons I listed above. An actual, large explosion at that distance sounds nothing like that track. If a real soundtrack for the explosion became available why wouldn't the more reputable news organizations cover that? The bottom line, as an investigator, you need to prove your source is legitimate and that has not been done.

 

[NUCENG]

Hot fuel rods in the open would evaporate CsI-molecules and CsI clusters. But this is very soluble in water. When cooling with seawater (NaCl mostly), it is impossible to distingish between solutions of (CsI + NaCl) and (CsCl + NaI). In water, the Cs+ ions and the I- ions are independent. And not especially reactive.

Yes, and over time radio-Iodine decays leaving excess Cs which remains in solution creating Cs+ ond OH- ions and Hydrogen gas, but at a much smaller scale than metal water reactions. As I understand it the point is that Cs and I are released as Cs I and once in water stay there unless something disturbs the equilibrium - like iodine decay or a solution which becomes acidic producing HI and H₂ gas.

As to evaporation CsI is aglomerative (forms clumps) and a particulate. The NUREGs I have listed tell me that it setlles out of the air on horizontal surfaces and tends to plate out as water evaporates. It sounds to me like it may require pretty aggressive boiling to get it airborne and that it tends to settle thereafter as "fallout."

Am I missing your point? Or am I once again exceeding my ignorance threshold for chemistry?

 

[clancy688]

I'm sorry - I don't follow what you are saying.

Are you saying that all the damage to Bldg 4 came from explosions of the other buildings?

I'm saying that the damage of Bldg 4 couldn't come from explosions of the other buildings... ^^;

Since there was no change in rubble, building damage etc. at the other three Units during the time when the damage at Unit 4 happened.

But it's still the most likeliest thing coming to my mind when thinking about the damage at Unit 4. I have no clue how these damages could have come from inside.

So my posting was very paradox: I told you what I thought was the most likely damage cause and provided prove why my thought couldn't be right. ^^'''-------------------------------------------------------------------------------------------------

Here's the T-HAWK Video in nice quality:

 

[Jorge Stolfi]

NUREG-1465 "Accident Source Terms for Light-Water Nuclear Power Plants" ... I would also refer you to NUREG/CR-5950" Iodine Evolution and pH Contro"l , NUREG/CR5732 "Iodine Chemical Forms in LWR Severe Accidents" , and there are other discussions of Cesium Transport.

Thanks for the references. However the search site you gave cannot find any of those NUREG reports. Do you have another source?

... estimates that 95% of Iodine is released as CsI. Both of these elements are highly reactive and what would be more likely to form than two highly reactive ions of opposite polarity?

That matches my understanding. If the Cs and I can migrate in the fuel, and there is an excess of cesium, most iodine should form CsI in the solid state, before water is added. When the fuel is placed in pure water, the CsI will dissolve and any excess cesium should combie with water and dissove as CsOH, with a small amount of H2 as a byproduct. If the solution is evaporated then all iodine will be in the form of CsI.

Once in solution there is no CsI or CsOH, just Cs⁺, I^- and HO^- ions. As long as the system remains closed the ratio of Cs⁺ to I^- in the solution should reflect the original "standard" ratio for that type and age of fuel.

However, if the solvent is borated saltwater with all sort of impurities (e.g. calcium leached out from concrete rubble), then there are many other ions present, in much larger concentrations. If that solution is kept in open container exposed to oxygen, I suspect that there will be many chemical pathways for I^- to be converted to I2 or HI and escaping the solution. On the other hand, the Cs will probably remain in solution, no matter what.

From the titles, the reports you cite seem to assume the solvent is the original (pure) reactor or SFP water. Have there been any studies of this scenario --- "borated saltwater plus rubble in an open pond"?

 

[NUCENG]

so what are we left with - the iodine could not have came from the fuel, and it couldn't have came from the aerial deposition (see Gundersen) unless it is much, much worse than Chernobyl already. Hell, with this much deposition they couldn't be able to even work on site.
Then, with re-criticality, it would also have took a LOT of fissions to make this much iodine for it to be released without a lot of Cs-137 left over from reactor operation. The only logical explanation left is that fresh fuel in the spent fuel pool gone critical (with serious amount of fissions) and then got damaged. My understanding is that there's a lot of Cs (ultra-fine aerosol of Cs2O perhaps? and CsI but keep mind there's far more Cs than I) and I in the gasses in the fuel rods.
It would be better if there were I-134 figures also.

To summarize: if we are considering damage to old fuel, Cs-137 indicates far less damage than I-131 , a disagreement . The re-criticality fissioning of old fuel has to be non-negligible comparing to original fissioning of that old fuel in the reactor. I'd guess fresh fuel gone critical and was damaged most extensively, but I dunno, need calculations to conclusively show that. Need upper bounds on how much fissioning could have gone on there without it becoming too obvious.

To the contrary, Dmytry, I am saying the iodine does come from the fuel in the pool. But the low concentrations in the pool do not require a massive amount of damage to the fuel. Nor would it require criticality.

Gunderson points out that the explosions of units 1, 2, and 3 happened while there was still a roof on unit 4. His approximation of how much I-131 would have had to be released and deposited is correct.

I too would love to see additional isotopes reported for intellectual curiousity. TEPCO is reporting isotopes that are most important in terms of exposure to the public. I have to think they are pretty busy fighting to stabilize the plants. When you are up to your neck in alligators it may be tough to remember your original plan was to drain the swamp.

 

[Dmytry]

To the contrary, Dmytry, I am saying the iodine does come from the fuel in the pool. But the low concentrations in the pool do not require a massive amount of damage to the fuel. Nor would it require criticality.

Explain then the I-131 to Cs-137 ratio.

 

[|Fred]

Original video is from NTV/NNN , I was not able to find any Japanese version with a sound track. It does not imply that there was not one. I recall that those picture were taken from a helicopter, but can not source it.
Trying to figure out the true-fullness around the audio track is for me a waste of time, I'll rather focus on" prime "evidence for now

And I found an other version with a different sound track that sound as real as the other if not more http://www.youtube.com/watch?v=ly4rRKGx7xc&feature=related
Journalist commentate that they could hear the blast

 

[Jorge Stolfi]

I have no clue how these damages [to unit 4] could have come from inside.

Looking at the latest drone video, it seems that the rebar in the outer concrete shell happens to be anchored and segmented in such a way that the internal explosion ripped the bottom and sides of each "panel" more easily than the top side. Therefore several panels remained attached at the top, like curtains. Apparently they opened out and up during the explosion, then fell back, swinging into the building, only to remain trapped there by the rebar.

This mechanism may explain the paradox of several #4 panels that seem to have been pushed inwards. It also fits with the state of the North wall. There, some panels of the second row from the top detached completely from the wall but remained attached to the panels above them.

By some mechanism that I cannot fathom, the topmost horizontal concrete beam on the North face was pushed (or pulled?) inwards, while the concrete beam below it was pushed and bent outwards. Thus the concrete panels in the second row of the North face were left dangling in the air, a couple of feet away from the building.

 

[Borek]

on topic of chemistry... in what form would the Cs exist? Wouldn't it take away O from UO2 becoming Cs2O ? Then in water, CsOH ?
Cs is far more reactive than U. I'd expect any Cs to immediately grab the oxygen from UO2

Cs⁺ in water, no idea about the solid.

 

[NUCENG]

Thanks for the references. However the search site you gave cannot find any of those NUREG reports. Do you have another source?



That matches my understanding. If the Cs and I can migrate in the fuel, and there is an excess of cesium, most iodine should form CsI in the solid state, before water is added. When the fuel is placed in pure water, the CsI will dissolve and any excess cesium should combie with water and dissove as CsOH, with a small amount of H2 as a byproduct. If the solution is evaporated then all iodine will be in the form of CsI.

Once in solution there is no CsI or CsOH, just Cs⁺, I^- and HO^- ions. As long as the system remains closed the ratio of Cs⁺ to I^- in the solution should reflect the original "standard" ratio for that type and age of fuel.

However, if the solvent is borated saltwater with all sort of impurities (e.g. calcium leached out from concrete rubble), then there are many other ions present, in much larger concentrations. If that solution is kept in open container exposed to oxygen, I suspect that there will be many chemical pathways for I^- to be converted to I2 or HI and escaping the solution. On the other hand, the Cs will probably remain in solution, no matter what.

From the titles, the reports you cite seem to assume the solvent is the original (pure) reactor or SFP water. Have there been any studies of this scenario --- "borated saltwater plus rubble in an open pond"?

It does get complicated, doesn't it? In all my research I have yet to find a study of seawater as reactor coolant. That may have been a big OOPS. But I am probably following the same line of reasoning as the operators and managers at TEPCO. It is how we've been trained and that may help others point out where we may be off base. If so, I welcome finding out where I'm wrong.

Did you search using the title? Sometimes it can't find the document numbers. If you don't find them there try the Web Based ADAMS search on the NRC website. In the last recourse you may find some older documents by a google search of the document number or title. I have found all of these references and downladed them this way in the last month. Although I remember using some of them previously in engineering projects like conversions to the Alternative Source Term.