Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[clancy688]

I have found all of these references and downladed them this way in the last month.

Well, you could zip and upload them to a sharehoster... ^^

This would be very nice. :)

 

[Dmytry]

Cs⁺ in water, no idea about the solid.

I meant, when Cs₂O reacts with H₂O you get 2 CsOH
Cs+ and OH- i would think.

This entire talk about there being primarily CsI from the fuel sounds like BS to me, coming from some idea of there being just Cs and I. There's a lot of reactive stuff, like oxygen left over from original UO2 after U fissioned (or fissioned into something other than Cs or I). No reason to think Cs would bind to I (how would it find I?) rather than grab O from UO2 or grab free O from fission, or from the molecules broken up by irradiation. Cs and I are just few reactive things out of many.

 

[NUCENG]

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

I have tried to explain in previous posts that there is no fixed time corelation of the ratio of I-131 to CS-137 in samples from different locations. There is a clear progression of the ratios of the total Cs and I in the core after shutdown. However, at any given point of sampling this ratio can be higher or lower than the total core source term. Transport paths, chemical reactions, deposition, plateout, and reevolution of I gas can all change the ratio at a specific sample location. If all else remains constant, you may get information from trending results at a specific sample point over time. But in an accident like this even that will be difficult as conditions change.

In short, I can't explain the ratio in this sample. I am saying it can be explained without deposition or criticality or the kind of damage that would release large amounts of hydrogen. It doesn't prove these things didn't happen, it just means there is not yet proof they did happen.

 

[NUCENG]

I meant, when Cs₂O reacts with H₂O you get 2 CsOH
Cs+ and OH- i would think.

This entire talk about there being primarily CsI from the fuel sounds like BS to me, coming from some idea of there being just Cs and I. There's a lot of reactive stuff, like oxygen left over from original UO2 after U fissioned (or fissioned into something other than Cs or I). No reason to think Cs would bind to I (how would it find I?) rather than grab O from UO2 or grab free O from fission, or from the molecules broken up by irradiation. Cs and I are just few reactive things out of many.

PhD may just stand for Piled Higher and Deeper, but I have references that I will try to make available. I asked Clancy688 for a how to.

This is one quote from NUREG-1465

"3.5 Chemical Form
The chemical form of iodine and its subsequent
behavior after entering containment from the reactor
coolant system have been documented in
NUREG/CR-5732, Iodine Chemical Forms in LWR
Severe Accidents (Ref. 18) and in ORNLITM-12202,
"Models of Iodine Behavior in Reactor Containments,"
(Ref. 21).

The results from Ref. 18 indicate that iodine entering
the containment is at least 95% CsI with the remaining
5% as I plus HI, with not less than 1% of each as I and
HI."

Authors are listed as: L Soffer, S. B. Burson, C. M. Ferrell,
R. Y. Lee, J. N. Ridgely

If you disagree with the number, I can only say it isn't my BS.

 

[ascot317]

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

The audio doesn't have to come from the same source as the video.

Maybe someone with a camera or audio recording equipment captured the sound but not the explosion, maybe at a different location, and the two sources were thrown together.

 

[|Fred]

The explosion rips off the roof from the southeast corner, The expanding gas from the explosion continues to lift the roof slab off of the girders and billow it like a sail full of air, the weight of the what is left of the roof slab is borne by the north wall of the building. It begins to fall back into the building, dragging part of the north wall inward and downward (D)

Makes me go mmm.
looking at your figure D, I understand that you think that falling back , the former north edge of roof tar slided in the building, that the sail broke and while some of the roor tar had cut and slide the rest broke and went away some how.
Most of the roof tar is in my opinion between the turbine building and the east wall.
but above the line o breakage of the sail of the stabbing tar is not consistant with what I'm seeing: the rising edge sticking out is too perfect , rectiline; for me it is the former northern edge of the building roof tar; and if so .. The bending does not fit your theories as I understood it.

if anything I'll would rather think for now that the bended slided in tar is a consequence of the roof giving down and in.

Maybe someone with a camera or audio recording equipment captured the sound but not the explosion, maybe at a different location, and the two sources were thrown together.

In deed, as for the rest my opinion stand

 

[razzz]

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

In that German news sound track you can also hear four distinct louder sounds going on. (Yes it is 4 distinct loud sounds not 3)

In the NTV version the telephoto lense was ready and waiting for the explosion so I would think there was a long range mike aimed also to pickup sound (like those miniature satellite dishes you see in football broadcasts) and that's why the delayed audio sounds surreal (magnified or concentrated). Also, in my mind, the extracted sound graph matches the cloud formation.

 

[Dmytry]

In short, I can't explain the ratio in this sample. I am saying it can be explained without deposition or criticality or the kind of damage that would release large amounts of hydrogen. It doesn't prove these things didn't happen, it just means there is not yet proof they did happen.

You're speaking in too abstract terms. Making it sound that there's something small to explain.
When was the reactor 4 shut down? Sometime before 29 November 2010 from, what I can find.
http://www.wolframalpha.com/input/?i=(11th+march+2011+-+29+November+2010)/(8+days)
at least 12 half lifes. That's factor of 4000 edit: and for 6 months that is a factor of millions.

http://www.world-nuclear-news.org/RS-Most_fuel_in_Fukushima_4_pool_undamaged-1404117.html
reported values:
220 Bq/cm3 of iodine-131, 88 Bq/cm3 of caesium-134 and 93 Bq/cm3 of caesium-137.
2x iodine to caesium.
Elsewhere (seawater, puddle water, soil samples, everything) nowadays they are measuring well less than 8x iodine to caesium.

You need to explain factor of more than 1000 better releasing of iodine than caesium in the pool versus the reactors (or for 6 months, factor of more than million). You don't explain it but you say it can be explained. I say until someone explained it, we'd better assume it is going critical there (or the aerial deposition is insanely high, which might well be true, i'd expect then it to be confirmed sometime by the bio-ionization-chamber measurements :/ [a dark pun at chernobyl's 'bio-robots'] ) 30GBq/m^2 that is a lot rly.

edit: and I don't believe in special role of CsI due to there being a lot more different elements and compounds besides Cs and I.

 

[Jorge Stolfi]

Did you search using the title?

Thanks for the tip, serching by title worked fine. From the first ref:

The results from Ref. 18 indicate that iodine entering
the containment [in case of an accident that leaks
the reactor coolant water into the containment]
is at least 95% CsI with the remaining
5% as I plus Hi, with not less than 1% of each as I and
HI. Once the iodine enters containment, however,
additional reactions are likely to occur. In an aqueous
environment, as expected for LWRs, iodine is expected
to dissolve in water pools or plate out on wet surfaces
in ionic form as I-. Subsequently, iodine behavior
within containment depends on the time and pH of the
water solutions. Because of the presence of other
dissolved fssion products, radiolysis is expected to
o man d lower the pH of the water pools. Without any
pH control, the results indicate that large fractions of
the dissolved iodine will be converted to elemental
iodine and be released to the containment atmosphere.
However, if the pH is controlled and maintained at a
value of 7 or greater, very little (less than 1%) of the
dissolved iodine will be converted to elemental iodine.

If I read correctly, the report also says that about 35% of the iodine and 25% of the cesium present in the fuel will be released with the coolant leak, in the early stages at least. is this correct?

The second ref (summary) says

In situations where pH levels fall below -7, the formation of I2 will occur in irradiated
iodide solutions. A correlation between pH and iodine formation is needed so that the amounts
of I2 in water pools can be assessed. This, in turn determines the amount of I2 in the atmosphere
available for escape by containment leakage. [...] The most important acids in containment will be nitric acid (HNO3), produced by irradiation of water and air, and hydrochloric acid (HCI), produced by irradiation or heating of electrical cable insulation. The most important bases in containment will be cesium hydroxide,
cesium borate (or cesium carbonate), and in some plants pH additives, such as sodium hydroxide
or sodium phosphate.

If the seawater was treated with sodium borate, it should probably be alkaline. If they used boric acid, I don't know. B(OH)3 seems to be a weak acid; will it be enough to lower the pH below 7? In hot water?

(My greatest achievement as a teenage chemist was distilling ethanol with boric acid to obtain something which I fancied to be ethyl borate. At least, it burned with a nice lemon-green flame, as theory said it would. Presumably that would mean that B(OH)3 does act like an acid? )

The last report you cited seems to have a more limited scope than the first. But its main conclusion, again, seems to be

In systems where the pH was controlled above 7, little
additional elemental iodine would be produced in the containment atmosphere. When the
pH falls below 7, it may be assumed that it is not being controlled and large fractions of
iodine as I2 within the containment atmosphere may be produced.

My conclusion is that, given the unknown/messy chemistry and the unusual physical conditions of the pool, a low concentration of radiogenic iodine in the pool water, a month after the accident, may not imply low level of fuel damage, since an unknown amount may have escaped as I2 or HI with the steam. The level of radioactive cesium in the water may be a better indicator. What does the latter say?

 

[Borek]

The results from Ref. 18 indicate that iodine entering
the containment is at least 95% CsI with the remaining
5% as I plus HI, with not less than 1% of each as I and
HI.

Strange way of describing the reality.

Are they dissolved? Are Cs⁺ and H⁺ and I^- the only ions present? What is I - is it intended to be I^- (if so - why CsI and HI are not listed as ions) or I₂? I don't get it.

If solution doesn't contain anything but Cs⁺ and H⁺ and I^- 95% & 5% can make a little bit of sense, although in reality it means some known concentration of I^-, and two counterions - Cs⁺ and H⁺ - in 19:1 molar ratio. But usually solutions are much more complicated and thay contain many different ions as well, it is easier then to list concentration of each ion separately, and don't try to make compounds out of these. There is no difference between solution prepared by mixing CsI and NaCl and solution prepared by mixing NaI and CsCl (assuming we did minimal effort to use correct concentrations).

 

[Ms Music]

From the coloring and shape, I am beginning to suspect that it is concrete wall panel from #4's own wall, that somehow got blown upwards to land on its own roof.

No, the simplest explanation is the correct one. It is a piece of the roof[...]

Hmm, you're right! The corrugation pattern on the underside is visible in the following photo from houseoffoust.com:

(img removed from quote)

Another beautiful theory slain by ugly facts.

Rowmag and Tcups, can I please take a moment to say THANK YOU! Thank you for these two absolutely pure rational logical conclusions. This thread is becoming so wildly speculative, I am almost amazed people haven't come out and said these explosions were an inside job...

 

[HowlerMonkey]

The audio doesn't have to come from the same source as the video.

Maybe someone with a camera or audio recording equipment captured the sound but not the explosion, maybe at a different location, and the two sources were thrown together.

I think you're right about the audio may have come from another source.

If this audio came from a source far removed from the camera, the distances used here almost guarantee that nothing will match to what is seen on the video.

Video cameras are notorious for having compression and limiting that removes the peaks and lows of the dynamics in order to work with the rather limited dynamic range in which most video is broadcast.

Even FM stereo radio quality audio has limited dynamic range that ruins many an artist's best intents which is why a strong guitar intro. to a song will disappear into the mix once the rest of the instruments come in.

Listen to that same song on vinyl or a good CD and you can clearly see what broadcast "compression" or "optimization" does to dynamic range.

It is likely the camera audio simply sucked.

There is no conspiracy save for the fact that they needed something more dramatic.

One more thing...You can't really use youtube video for any scientific discussion because it seems one can send a perfect concert music video clip and the sound ends up skewed timewise or compressed by youtube in the name if lower bandwidth.

 

[razzz]

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.

Ya think maybe installing spring loaded hinges on the side panels to allow them to swing open then close again would prevent so many flying objects?

 

[clancy688]

PhD may just stand for Piled Higher and Deeper, but I have references that I will try to make available. I asked Clancy688 for a how to.

Wouldn't have noticed your message if you wouldn't have posted this... ^^;

You got mail.

My conclusion is that, given the unknown/messy chemistry and the unusual physical conditions of the pool, a low concentration of radiogenic iodine in the pool water, a month after the accident, may not imply low level of fuel damage, since an unknown amount may have escaped as I2 or HI with the steam. The level of radioactive cesium in the water may be a better indicator. What does the latter say?

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110414e20.pdf

around 100 Bq/cm³.

 

[htf]

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.

Hm, I am confused:

1 Ci = 3.7e10 Bq

5.03E-3 Ci/MW * (1/.33 * 760 MW ) = 11.58 Ci = 4.3e11 Bq

1 foot = 30.48cm - so I get 9.06e8cm^3 for the SFP.

And with your 5% release I get 4.3e11 Bq * .05 / 9.06e8cm^3 = 24 Bq/cm^3

Did I get something wrong?

 

[clancy688]

5.03E-3 Ci/MW * (1/.33 * 760 MW ) = 11.58 Ci = 4.3e11 Bq

I think there's the problem. 33% is multiply by 0.33, not divide. Or divide by 3.But I'm not sure as to what those 33% efficiency apply to in the calculations.Edit: Screw that - you're right... ^^;

33% = the 760 MWe, 100% = total MWt

Hm, I also get your results...But I think there are more factors contributing. First, it has not been 6 but 5 months or less since shutdown. And second, the pool is totally full AND there's probably debris inside, plus it's probably not filled up to the top. So if I double your 24 Bq/cm³ three times (three half times, less then one month) I get ~200 Bq/cm³. And because of the fill status /debris / water height there's probably not 900 billion cm³ water inside, but less.

 

[elektrownik]

Robots entered Reactors Nos. 1 and 3 on Sunday and measured the radiation inside. But when two robots entered Reactor No. 2 on Monday, the steam inside was so dense that a robot mounted with a camera was unable to get a clear image of a radiation sensor carried by the other robot, Japanese officials said.

Source: http://www.nytimes.com/2011/04/20/world/asia/20japan.html?_r=1&ref=world"

 

[PietKuip]

Source: http://www.nytimes.com/2011/04/20/world/asia/20japan.html?_r=1&ref=world"

"The radiation sensors are not part of the robots’ original equipment, and must be carried separately without the capacity to store readings, officials said. "

Amateurs.

 

[MiceAndMen]

After 9/11 many plant and site drawings were removed from ADAMS and were considered as Safeguards information. These drawings may have been missed or a mistake. Or maybe somebody finally figured that this wouldn't really help a terrorist.

That could definitely be part of the reason. After the I-35 bridge in Minneapolis collapsed in 2007, I was looking for maps of the area. At the time there was a proposal by an energy company to build a generating station just upriver of the site. The Dept of Energy's website had specifically pulled the plan documents from public view because they didn't want evildoers to see them. And that was not a NPP. Some federal law mandates it, as far as I know.

I'm actually surprised the NRC has so much information online, to be honest. I have a feeling that (without going over to the black helicopter side too far) if you went to the NRC with a list of blueprints you wanted to look at that you'd end up on somebody's watch list. I'm not generally prone to paranoia, but in my web searches for 'hydrogen', 'explosion', 'nuclear' and 'blueprints', some of the hits that come back - the stuff I'm not looking for - give me pause to wonder what anyone watching my search activity might think.

 

[Dmytry]

Source: http://www.nytimes.com/2011/04/20/world/asia/20japan.html?_r=1&ref=world"

idiots. They've been offered KHG robots.

 

[bytepirate]

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.

looking at the sources (digitalglobe pics, drone video) already posted, i can not imagine any outside source for the damage in #4.
the most damage is on the south side, opposite of #3.
you can see rebar bended outside on all 4 sides of the building.
the damage on the north side doesn't look like an impact as well, rather as if the pillars had been knocked of quite low from the inside, then the roof went inwards.
maybe (though i don't vote for that) it is possible, that something from outside had triggered the explosion in #4, but most of the damage has been done from the inside.

it's hard to tell, what is #3 and what is #4 from the angle of the webcam, but it looks like, that there has been lot of black smoke, when #4 exploded (even an hour after the explosion): (at 2:24)

fires have been reported, but i can't find any soot.

btw: i would estimate the mass of the roof quite low, iron sheets with tarboard, not likely to cause much damage (to concrete pillars) when coming down from a short flight.

what exploded in #4?

hydrogen released by zircaloy oxidation?
would require a dry pool, water spray started days after the explosion -> not possible
steam explosion?
i have not found any reference to this possible risk anywhere in the literature. were all the engineers that did the risk analysis wrong? rather not -> quite unlikely
acetylen?
can't tell, but has been rebutted in this forum -> unlikely

what else is left:
hydrogen generated by radiation?
hydrogen generated in steam bubbles at the bottom of the fuel?
both unlikely (the 'steam explosion' argument is valid for both).

i am running out of ideas

anyone?

I am almost amazed people haven't come out and said these explosions were an inside job...

if i could make up a motive, i would ;-)

 

[WhoWee]

idiots. They've been offered KHG robots.

That was over 2 weeks ago - didn't they accept?

 

[M. Bachmeier]

RE: THE EXPLOSIONS AND PATTERN OF DAMAGE AT BLDG 3 & 4 -- SIMILARITIES AND DIFFERNECES


@Fred:
M. Bachmeir did extensive analysis of the sound frequencies and concluded that Bang 1 and Bang 2 were similar and were explosions and that Bang 3 was fundamentally different from the first two, as I recall. Maybe he would comment again about the possibility of one of the audible bangs being a mechanical transient from a large falling object.

Ya, that was in the working notes/speculation I forwarded to you TCups. The problem is I can't say for certain from the data that the third explosion is wholly different from the previous two, because I was not able to eliminate the possibility that some post processing (normalization, volume adjustment etc.) had been applied to the sound track.

The best evidence for that is in the stretched and pitch adjusted remake (4 x longer, original frequency 592.593 Hz. - 705.882Hz). Listening to that playback is very revealing. Echos from each explosion (between the explosions). Five distinct sound events. The second explosive sound hit the highest peak energies, but the third had greater energy output overall.

Note: the two sound events at the beginning and end both resemble steam release.

If the third sound is the collapse of the FHM into the SFP, that would explain the last sound (superheated... rapid boiling/steam) triggered when the FHM made contact with the SFP.

If anyone knows where I can upload the modified (stretched) audio file, please let me know.

 

[elektrownik]

about unit #4 explosion: "IF" there would be fuel in core then this explosion wouldn't be simpler to explain ?

 

[NUCENG]

You're speaking in too abstract terms. Making it sound that there's something small to explain.
When was the reactor 4 shut down? Sometime before 29 November 2010 from, what I can find.
http://www.wolframalpha.com/input/?i=(11th+march+2011+-+29+November+2010)/(8+days)
at least 12 half lifes. That's factor of 4000 edit: and for 6 months that is a factor of millions.

http://www.world-nuclear-news.org/RS-Most_fuel_in_Fukushima_4_pool_undamaged-1404117.html
reported values:
220 Bq/cm3 of iodine-131, 88 Bq/cm3 of caesium-134 and 93 Bq/cm3 of caesium-137.
2x iodine to caesium.
Elsewhere (seawater, puddle water, soil samples, everything) nowadays they are measuring well less than 8x iodine to caesium.

You need to explain factor of more than 1000 better releasing of iodine than caesium in the pool versus the reactors (or for 6 months, factor of more than million). You don't explain it but you say it can be explained. I say until someone explained it, we'd better assume it is going critical there (or the aerial deposition is insanely high, which might well be true, i'd expect then it to be confirmed sometime by the bio-ionization-chamber measurements :/ [a dark pun at chernobyl's 'bio-robots'] ) 30GBq/m^2 that is a lot rly.

edit: and I don't believe in special role of CsI due to there being a lot more different elements and compounds besides Cs and I.

Please reread my earlier posts. I have given my best to give people a strawman to shoot at. I may be wrong, but I am on record with my guesstimates.

I have explained how much Cs and I can be released from the fuel gap into a spent fuel pool. There are other explanations including criticality, but there is no proof of that either (measured neutron radiation, newly generated short lived isotopes, etc).

You asked me to explain the Cs/I ratio. I told you I can't because I haven't got enough information to calculate the isotopic transport to the sample location. Telling me I "need to explain" it again is a circular absurdity.

I referenced my source for the 95% CsI number. You don't like it. OK.

I don't know how to answer better. Perhaps you can explain where I am wrong with something better than "I believe" or is that not abstract?

 

[|Fred]

idiots..

That's the spirit! they used i-robot http://www.irobot.com/

 

[htf]

But I think there are more factors contributing. First, it has not been 6 but 5 months or less since shutdown. And second, the pool is totally full AND there's probably debris inside, plus it's probably not filled up to the top. So if I double your 24 Bq/cm³ three times (three half times, less then one month) I get ~200 Bq/cm³. And because of the fill status /debris / water height there's probably not 900 billion cm³ water inside, but less.

But what if it is leaking? There was also a lot of steam generated, so a significant fraction of the Iodine could have been released to the atmosphere. They had to fill it many times. You can find good reasons why the 24 Bq/cm^3 are an overestimation.

There is a lot of uncertainty. The observed Iodine could be produced by reactor 4 during normal operation 6 month ago. But the estimated 24 Bq/cm^3 are less convincing then the much higher figures posted by NUCENG. My calculation may be wrong, though.

Anyway - the explanation given by TEPCO gives a deep insight. What are they operating? Windmills?

 

[NUCENG]

Thanks for the tip, serching by title worked fine. From the first ref:



If I read correctly, the report also says that about 35% of the iodine and 25% of the cesium present in the fuel will be released with the coolant leak, in the early stages at least. is this correct?

The second ref (summary) says



If the seawater was treated with sodium borate, it should probably be alkaline. If they used boric acid, I don't know. B(OH)3 seems to be a weak acid; will it be enough to lower the pH below 7? In hot water?

(My greatest achievement as a teenage chemist was distilling ethanol with boric acid to obtain something which I fancied to be ethyl borate. At least, it burned with a nice lemon-green flame, as theory said it would. Presumably that would mean that B(OH)3 does act like an acid? )

The last report you cited seems to have a more limited scope than the first. But its main conclusion, again, seems to be



My conclusion is that, given the unknown/messy chemistry and the unusual physical conditions of the pool, a low concentration of radiogenic iodine in the pool water, a month after the accident, may not imply low level of fuel damage, since an unknown amount may have escaped as I2 or HI with the steam. The level of radioactive cesium in the water may be a better indicator. What does the latter say?

The larger releases come from inital fuel melting in the "early in-vessel" phase of a severe accident. I used only the 5% release for a gap release and that was more than enough to result in the measured concentrations of Cs and I in the fuel pool.

If pH became acidic it would result in increased airborne I-131 on site and downwind. The sample trends don't show that.

In earliers posts I calculated Cs concentrations from the gap release could produce sample concentrations up to 1E6 Bq/cm³. The measured results are very small compared to that in both SFP2 and SFP4.

Yes seawater chemistry and other contaminants in debris dumped into the pool can complicate matters, but this is the best I have found. I am open to a better explanation.

 

[bytepirate]

about unit #4 explosion: "IF" there would be fuel in core then this explosion wouldn't be simpler to explain ?

if we consider the RPV and the SFP (more or less) connected, and i think we have to, that would not make a difference, imho.

one might make up a scenario, where a core is in the RPV. RPV and SFP are not connected. RPV water boils off - explosion - water from the SFP floods the RPV...

but this is of the same likeliness as this: https://www.physicsforums.com/showpost.php?p=3245053&postcount=3653

not likely at all.

 

[cphoenix]

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.

Stagnant, near-boiling-hot water at the bottom of the pool would contain 24 kg TNT equivalent per cubic meter. 125 C, 4 J/gC, 1E6 g/m^3. Do the arithmetic. 1E8 J = 24 kg TNT.

There are at least three ways that convection could be stopped, and hot water accumulate:

1) Rack falls over.
2) Something flat falls on rack, covers top.
3) Rack knocked off supports, sitting on pool bottom.

How many cubic meters of water could be trapped? 1E2? 1E3? We could easily be talking tons of TNT. Thousands of cubic meters of steam.

If hot water accumulated, then sufficient perturbation (not necessarily much of a disturbance) would create a geyser. Release hundreds, thousands, maybe hundreds of thousands of cubic meters of steam indoors in less than a second... and you lose your roof and walls.

Chris

 

[MiceAndMen]

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.

We need to get some information from the horse's mouth, so to speak. Whose camera recorded the explosion? Where was it located? Did it also record audio? If the released video shown on TV - I would heavily, heavily discount anything found on YouTube - had an audio track, where was the microphone that recorded the audio?

As bad as the press is in the US, I'm sure all those questions would have been asked and answered already if a reactor building exploded here. Maybe they are asking those questions in Japan and we're just not aware of it due to the language barrier that keeps us from really following the Japanese news coverage, blogs and other websites there.

EDIT:

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.

Thanks, Fred. I replied above before seeing your post. It's a start. I, too, remember hearing initially that a helicopter recorded the video, but I don't remember where I heard that.

 

[Dmytry]

Stagnant, near-boiling-hot water at the bottom of the pool would contain 24 kg TNT equivalent per cubic meter. 125 C, 4 J/gC, 1E6 g/m^3. Do the arithmetic. 1E8 J = 24 kg TNT.

There are at least three ways that convection could be stopped, and hot water accumulate:

1) Rack falls over.
2) Something flat falls on rack, covers top.
3) Rack knocked off supports, sitting on pool bottom.

How many cubic meters of water could be trapped? 1E2? 1E3? We could easily be talking tons of TNT. Thousands of cubic meters of steam.

If hot water accumulated, then sufficient perturbation (not necessarily much of a disturbance) would create a geyser. Release hundreds, thousands, maybe hundreds of thousands of cubic meters of steam indoors in less than a second... and you lose your roof and walls.

Chris

scary. Now i think your hypothesis is VERY plausible.

 

[cphoenix]

looking at the sources (digitalglobe pics, drone video) already posted, i can not imagine any outside source for the damage in #4.

I agree.

what exploded in #4?

(trimmed by cphoenix)

steam explosion?
i have not found any reference to this possible risk anywhere in the literature. were all the engineers that did the risk analysis wrong? rather not -> quite unlikely

Thanks for doing the literature search.

I disagree that "they didn't think of it ahead of time" means "it's likely impossible." Very simple mechanics and arithmetic says it is possible. Human nature says it's easy to miss.

I knew about water under pressure - A couple of years ago, I happened to heat a glass of water under oil in the microwave, and I saw it blow liquid all over the place quite suddenly. And yet, knowing that the building 4 explosion happened with no obvious source, it took me a week and several wrong guesses to think of the steam explosion mechanism.

When I did the arithmetic, I was shocked at the amount of energy that could be held in the water.

And then, despite knowing how geysers work, I didn't think of geysers until someone else used the word several days later.

And even now, lots of people on the list dismiss the idea out of hand, for no better reason than "I don't see what would trap the water." After a 9.0 earthquake!

Bottom line, it would have required creativity and luck to think of this mechanism at all. Once they thought of it, it would be pretty easy to verify.

Can we agree that, if they had thought of it, they would at least have said, "If a metal plate falls into the pool and settles on top of the racks, get it off of there damn quick before the water has time to heat up even a few degrees." To me, the absence of that caution indicates that they did not consider the geyser effect.

So take your pick:
1) Geysers don't happen.
2) They didn't think of geysers.
3) They decided there was no way to set up the required conditions - which means, no way to block convection.

I'm going with "2," but I could also go with "3, and they were wrong." It's way too early to say "3, and they were right."

Chris

 

[TCups]

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.

Heck, SB, this is the internet, and I am not writing a PhD dissertation. We are all just "out there" on the net, trying to figure out what has happened, digging for whatever information is available -- videos, pictures, and links -- just fanning our mental puds, so to speak, and trying to figure out what has happened. I didn't weight the audio track as "key" to any of my free wheeling concoctions about what may have happened at Fukushima, but neither did I dismiss it as absolute fraud, particularly after getting what I took to be a pretty "sound" opinion from another of my online friends here at this thread. I confess that my talents (which may be too strong a word), such as they are, are more in tune to the visual than the audio puzzle. And I do love a good puzzle.

 

[M. Bachmeier]

We need to get some information from the horse's mouth, so to speak. Whose camera recorded the explosion? Where was it located? Did it also record audio? If the released video shown on TV - I would heavily, heavily discount anything found on YouTube - had an audio track, where was the microphone that recorded the audio?

As bad as the press is in the US, I'm sure all those questions would have been asked and answered already if a reactor building exploded here. Maybe they are asking those questions in Japan and we're just not aware of it due to the language barrier that keeps us from really following the Japanese news coverage, blogs and other websites there.

I strongly agree with you. Even if someone is holding on to a larger video for resale, a few details would be helpful. Camera distance. Audio source. Video length. Audio length if different from camera. Distance of audio source if different from camera.

Contrary to previous opinions, it would not be that easy to fake the audio for the video in question, not with the kind of visual synchronization I found.

Note: if the audio was a fake, it would have been the same length as the video... all part of post processing... *video* 13.25 sec. approx. *audio* 12.77 sec. ?