Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Bandit127]

Your speed and height calculation would agree with a ballistic trajectory :

http://img641.imageshack.us/img641/2843/ballisticf.jpg


(Though I think you mean 180 km/hour instead of 1800)

So - can we assume it didn't float up on the top of clouds or ballons then? Or do I have to still consider (the equivalent of) a piano soaring atop a cumulus feasible?

 

[AntonL]

(Though I think you mean 180 km/hour instead of 1800)

Yes 180 it is - edited my post accordingly

 

[~kujala~]

TEPCO's thinking is evolving regarding the missing water of unit #1:

The utility says the leaked water is likely in the basement of the reactor building -- still a no-go zone due to concerns over high radiation levels.

http://www3.nhk.or.jp/daily/english/13_34.html

I bet it's not going to take long until they admit that a leak from the basement of the reactor building into the groundwater is also likely - a scenario that should perhaps not be possible but seems to be happening under #1 and #4.

 

[MadderDoc]

Also note that MPEG/JPEG encoding creates complicated artifacts. The shape of any detail that is smaller than 8x8 pixels is usually mangled beyond recognition. (If the detail persists unchanged over several frames you may recover some of the lost information by aligning and averaging, but that is not the case here.)

As a general remark I totally agree, and there are indeed many very poor videos of these explosions, horribly re-compressed and color-releveled. The details we are looking at in this video is far, far larger than 8x8 pixels. A high quality HD source video was carefully selected for the exposee of the explosion at unit 3. While we should take care not to put too much trust in the images we see, we should also take care not to take them on as less trustworthy than they are.

Moreover, color information is lost for objects that are too bright: the camera will just record white.

True. However when we see a flash of fire first being almost white aka very bright, and the next frames show the flame turning through shades of yellow to red, we can be pretty sure that what we see, is the effect of decreasing temperature of the flame.

 

[jim hardy]

""""I almost feel a bit like knighted .

And seriously isn't recriticality inside the RPV much much more likely than in the SFP? (If one assumes something actually did go critical.) """""

well check the references. It must be deemed possible by somebody in academia.

The idea falls apart if the pressure readings after event are real, unless one can hypothesize either a leak that healed itself or claim they were pressure difference across the leak as steam exited through it.

It will play out and somebody will be right. thanks for looking. i too feel vindicated.

 

[MadderDoc]

How about the rail for the big overhead crane banged against the pillar during the explosion?
(Where is it now? I don't know.)

On a scale from 1 to 10, how likely would you say that a collision with the rail of the big overhead crane would have left the pillar standing?

Edit: I have wondered myself where that rail has gone, I've seen indications that it may have been hammered down in the service floor, at the inside of the pillars.

 

[TheMundun]

There has been some discussion today about whether the Drywell breached and hot gases escaped into the Service Floor triggering another explosion. I hope this post will contribute more evidence to what exactly took place.
As I can run the sound track of Unit 3 in slow motion using VLC Media Player, I managed today to find some software that enabled me to see the changes in the frequency spectrum as the track played and so carry out further analysis of the frequencies and sounds. I took screen grabs at various points through the sound track, putting them into a pdf, see attached.
One of my discoveries is that the main harmonic frequency of the reactor /primary containment seems to be 1227.06 Hz.
More importantly, what I also found today was that around 0.4 seconds after the first explosion there is a quiet hiss with a peak frequency of around 2842Hz and then again 0.4 seconds after the 2nd explosion started and before the metallic sound starts, there is a much louder and clearer hiss with a peak of around 2850Hz. Interpreting these hisses, they appear to indicate that there were two escapes of gas from somewhere following the two explosions, both presumably originating in a vessel that breached. Whether it was the same vessel or two different vessels, I cannot say.
What I find bizarre is that the start of the track, the main sound centres around the harmonic frequency mentioned above yet just before the 1st explosion and between the 1st and 2nd explosions, the whole complex went practically dead quiet. Any ideas why?
See attached for the screen grabs. On opening, please rotate the slides to landscape (I did try saving them as landscape but...).

Geoff

 

[pdObq]

On a scale from 1 to 10, how likely would you say that a collision with the rail of the big overhead crane would have left the pillar standing?

Edit: I have wondered myself where that rail has gone, I've seen indications that it may have been hammered down in the service floor, at the inside of the pillars.

Well, that would depend on the type of collision and the speed of that rail, so I don't really know. It could also have been part of the roof trusses bumping onto the pillar while flying through the air...

 

[ElliotLake]

Forgive me if this was done before, after having found the location of the camera by aligning the HV line tower with the left most stack and reactor unit 1 (https://www.physicsforums.com/showpost.php?p=3296107&postcount=6694") and the heading of the sight line being 36.04 degrees to the centre of unit 4 south wall, and taken that wall as 34 metres. We then can scale the photo of the explosion quite accurately (34 Cos 36.04 = 27.5)

As the building top is OP+55 metres making the stacks about 90 metres high from ground level.

The speed of the column rising is about 50 m/s or 180km/hour

I also added some further dimensions, showing that the roof sheets got carried up to around 150 metres above the roof top of the reactor buildings and tried to size the black object, the two white objects are about half the size.
[PLAIN]http://k.min.us/inBoDM.jpg[/QUOTE]
Thanks for this.
If that black object is is roof sheeting though, it must have something substantial attached to it, as it neither looks nor moves like heavy metal sheeting I have seen peel off roofs in high winds.
Those move more the way leaves do, twirling and shearing sideways. Like flying blades, not blocky objects.
I would expect metal sheeting lofted by this explosion to not come down anywhere near vertically. The crumpled sheeting seen on the reactor grounds on the other hand, does look like what happens to free flying metal sheeting, not something still attached to framing.

 

[AntonL]

I would like to see a proper english translation of http://www.asahi.com/special/10005/TKY201105120706.html

By what I can make out it discusses un-published internal reports and documents by TEPCO that asahi claim now to have in their possession, more than 100 pages listing many parameters, trends, work groups etc. These documents reveal that on 13th March high radioactivity in or around Unit 3 were measured and observation of steam with high probability of hydrogen escaping into the building. (Unit 3 exploded on the 14th a day later)

If my interpretation of the machine translation is true, then Tepco have not only leaks in reactors.

 

[pdObq]

Thanks for this.
If that black object is is roof sheeting though, it must have something substantial attached to it, as it neither looks nor moves like heavy metal sheeting I have seen peel off roofs in high winds.
Those move more the way leaves do, twirling and shearing sideways. Like flying blades, not blocky objects.
I would expect metal sheeting lofted by this explosion to not come down anywhere near vertically. The crumpled sheeting seen on the reactor grounds on the other hand, does look like what happens to free flying metal sheeting, not something still attached to framing.

Were the concrete shield plugs on top of the dryer-separator storage pool? Could they be those flying "blades"? Where are they stored when they are not in place, possibly in the NW corner?? (I should really look at that service floor NRC document with the weights and stuff at some point...)

PS: The big chunk leaves a trail of dust when falling, I think that's one reason I think it might be something like concrete.

 

[NUCENG]

The EPA's RADNET site recently spiffed up their user interface, but they provide no guidance on interpreting the gamma graph's energy ranges. If anyone on the forum can associate isotopes with energy ranges that would shed some light. http://www.epa.gov/radiation/rert/radnet-data-map.html

For those of us in the SF Bay Area, a tip of the hat to UC Berkeley's Nuclear Engineering Dept. They've been monitoring air, rainwater, tap water, grass, soil, milk and food since mid March. They're running on student labor so the reports are updated only a few times a week http://www.nuc.berkeley.edu/UCBAirSampling

For detailed information on isotope decay see
http://atom.kaeri.re.kr/index.html

For direct conversion of dose from a radioisotope see FGR 11, 12
http://www.epa.gov/radiation/federal/techdocs.html

 

[MadderDoc]

<..>
PS: The big chunk leaves a trail of dust when falling, I think that's one reason I think it might be something like concrete.

Dust would seem to be to a concrete chunk that has been hurled 100s of meter in the air, like moss to a rolling stone. Could it be something hot, smoking? Several of the objects falling out of the cloud leave dust/smoke trails.

 

[Borek]

Also note that MPEG/JPEG encoding creates complicated artifacts. The shape of any detail that is smaller than 8x8 pixels is usually mangled beyond recognition. (If the detail persists unchanged over several frames you may recover some of the lost information by aligning and averaging, but that is not the case here.)

We've been through that eons ago, I would like to remind you all this quote:

I have known a couple of photo recon interpreters who told me it is hard not to see things after looking at a photo too long or too hard. I have spent a lot of time in BWR reactorbuildings and I don't recognize very much in the wreckage. We've already heard that there was a body in one photo. Next thing is likely to be somebody spotting bin Laden.

 

[Borek]

As I can run the sound track of Unit 3

Please search the thread - it is not clear (at least to some) whether the sound is really part of the recording and whether it was not added from some other source.

 

[MadderDoc]

We've been through that eons ago, I would like to remind you all this quote:

I'm afraid I don't get the message. Do you think this quote is memorable?

 

[MiceAndMen]

TEPCO's thinking is evolving regarding the missing water of unit #1:

http://www3.nhk.or.jp/daily/english/13_34.html

I bet it's not going to take long until they admit that a leak from the basement of the reactor building into the groundwater is also likely - a scenario that should perhaps not be possible but seems to be happening under #1 and #4.

What do they mean by reactor building "basement"? Are they referring to the excavated space where the torus is located underground? Are there additional subsurface rooms or spaces?

 

[Borek]

Well, it introduced Bin Laden to the thread.

Seriously, at about the time NUCENG posted his comment it was becoming obvious that blowing up images of dubious quality, with compression artifacts, with unknown white balance and so on, yields more problems than answers. I just wanted to remind you all about that.

 

[turbo]

Tough job Borek. Thanks.

 

[MadderDoc]

<..>blowing up images of dubious quality, with compression artifacts, with unknown white balance and so on, yields more problems than answers. I just wanted to remind you all about that.

Do you want us to stop looking at photos and videos and discussing what we see, such as to not cause any more of these 'problems'??

 

[Astronuc]

Do you want us to stop looking at photos and videos and discussing what we see, such as to not cause any more of these 'problems'??

If a photo is analyzed on a sound technical basis, then there is no problem. If a photo is analyzed with some wild speculation, then besides violating the guidelines, it is just a waste of space and our time.

The intent of the thread is for thoughtful discussion and sound technical content, not spurious or specious speculation. The failures of TEPCO are self-evident - they blew it big time - and all criticism (or disparagement in some cases) is not going to change the past. All we can do is learn and move on.

I would like those posting to provide good quality content with a sound technical basis, partly because there appear to folks in Japan looking for answers that are not forthcoming from sources in Japan, and secondly, the thoughtful commentary and sound technical basis is what sets PF apart from the noise out there on the internet.

 

[mikefj40]

For direct conversion of dose from a radioisotope see FGR 11, 12
http://www.epa.gov/radiation/federal/techdocs.htm

Thanks NUCENG. Unfortunately the EPA link is broken.

 

[Astronuc]

Thanks NUCENG. Unfortunately the EPA link is broken.

Link is fixed. It should be .html, rather than .htm

 

[MadderDoc]

If a photo is analyzed on a sound technical basis, then there is no problem. If a photo is analyzed with some wild speculation, then besides violating the guidelines, it is just a waste of space and our time.

Yes of course, one should be completely unreasonable not to agree with that. Thanks for the clarification.

 

[MadderDoc]

What do they mean by reactor building "basement"? Are they referring to the excavated space where the torus is located underground? Are there additional subsurface rooms or spaces?

I'd rather not speculate what they mean by the singular 'basement', but I have seen Tepco use the expression 'second basement floor' in some of their releases relating to unit 1. This would imply that in the eyes of Tepco there is in that reactor building at least two basement floors.

 

[mikefj40]

Link is fixed. It should be .html, rather than .htm

"Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Ingestion, Inhalation and Submersion" is interesting in itself but doesn't answer the question of which isotopes are associated with each energy band on the RADNET graph. http://www.epa.gov/radiation/rert/radnet-reno-bg.html

Is there a better thread for this topic?

 

[swl]

...yet just before the 1st explosion and between the 1st and 2nd explosions, the whole complex went practically dead quiet. Any ideas why?

Could the silence be caused by automatic gain control on the sound recording unit?

 

[ernal_student]

I would like to see a proper english translation of http://www.asahi.com/special/10005/TKY201105120706.html

By what I can make out it discusses un-published internal reports and documents by TEPCO that asahi claim now to have in their possession, more than 100 pages listing many parameters, trends, work groups etc. These documents reveal that on 13th March high radioactivity in or around Unit 3 were measured and observation of steam with high probability of hydrogen escaping into the building. (Unit 3 exploded on the 14th a day later)

That is correct. Let me translate those important points here:
"High radiation, not reported by TEPCO - Reactor 3, understanding the "before" of the hydrogen explosion" (This is the headline: it is not proper English, but I hesitate to smooth it out because that might give a twist to the meaning that is not intended)
"[...] inspite of having a picture of high radiation the day before [the explosion], [the data] was not made public."
"[This] has been confirmed from internal TEPCO documents."
"Asahi Newspaper has obtained documents covering the period from April 11 to April 30, a total of about 100 pages."
"concerning reactor 3, since the 13th high radiation data in the reactor building and likelihood of hydrogen buildup [are being/have been] described/mentioned/recorded"

 

[rowmag]

That is correct. Let me translate those important points here:
"High radiation, not reported by TEPCO - Reactor 3, understanding the "before" of the hydrogen explosion" (This is the headline: it is not proper English, but I hesitate to smooth it out because that might give a twist to the meaning that is not intended)
"[...] inspite of having a picture of high radiation the day before [the explosion], [the data] was not made public."
"[This] has been confirmed from internal TEPCO documents."
"Asahi Newspaper has obtained documents covering the period from April 11 to April 30, a total of about 100 pages."
"concerning reactor 3, since the 13th high radiation data in the reactor building and likelihood of hydrogen buildup [are being/have been] described/mentioned/recorded"

See also my post with a few highlights from those TEPCO documents:

Ok, here is some information you may be interested in. Apparently TEPCO has released some previously-unreleased internal notes on what was happening in the early days. Fascinating reading, published in today's Asahi Shimbun (paper edition). A couple highlights (bolding mine):

"3/12 10:17 Unit 1 venting starts." Has to be done manually, because can't get electricity working in time. One worker takes over 100 mSv in the operation.

"3/12 11:31 Unit 1 water level drops to 1 m below top of fuel."

Followed by some confusion about whether the venting actually worked or not, then...

"3/12 15:36 Sound of explosion at Unit 1"

"3/12 15:45 1 mSv/h measured at 1st floor of seismic bunker, 180 micro-Sv/h inside, several people injured."

"3/12 18:30 0.07 micro-Sv/h neutrons confirmed between North Gate and West Gate (possibility of criticality accident)"

Also, they were planning to open the blow-out panel on Unit 2, but then discovered that it had already happened by itself.

Would be interesting to find the whole thing. Not posted on Asahi website that I see.

Add: Someone has posted a photo of the story printed in the paper:
http://www.geocities.jp/swingi70/_gl_images_/P1020249toudenn.jpg

(Note: my bolding was to highlight things PietKuip might have been interested in. That post was in reply to one of his.)

 

[NUCENG]

"Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Ingestion, Inhalation and Submersion" is interesting in itself but doesn't answer the question of which isotopes are associated with each energy band on the RADNET graph. http://www.epa.gov/radiation/rert/radnet-reno-bg.html

Is there a better thread for this topic?

Depending on energy state each isotope decay produces a beta particle with a variable kinetic energy and discrete photon energy releases from the decay energy to the ground state. The different photon energy possibilities are listed in the nuclide table. Other types of decays are also listed in the nuclide table with a description of the energy levels. just click on the decay type and it will give you the decay energy diagrams.

http://atom.kaeri.re.kr/index.html

 

[ernal_student]

Apparently TEPCO has released some previously-unreleased internal notes on what was happening in the early days.

The only (perhaps in this context irrelevant) unclear point may be to what extent the documents have been "released" or whether they have been "obtained" in other ways. The wording of the related passages in the Asahi Newspaper article make me think that the second interpretation would be justified.

 

[rowmag]

The only (perhaps in this context irrelevant) unclear point may be to what extent the documents have been "released" or whether they have been "obtained" in other ways. The wording of the related passages in the Asahi Newspaper article make me think that the second interpretation would be justified.

Good point. I didn't read the front-page article carefully, just dove straight into the juicy bits.

I see it mentions that a TEPCO PR guy now says they "want to present an organized summary" at some point. I think the raw real-time notes are likely to be more informative, though. They let us know what they were thinking at the time, rather than what they think now (which may still not be correct). And if they edit it now, they are likely to leave out details that they currently think are irrelevant or mistaken, but which at some later date may prove significant after all.

 

[Azby]

It looks like TEPCO is moving forward with it's plan to cover Unit 1 in a steel frame covered with polyethelene sheets. This news item doesn't give an expected date of completion, but I seem to recall September being bandied about previously.

http://www3.nhk.or.jp/daily/english/14_02.html
http://english.kyodonews.jp/photos/2011/05/90962.html

Also a news item reporting that the NISA says there's (probably?) no need to fill unit 1 RPV with water.

http://www3.nhk.or.jp/daily/english/13_26.html

 

[Jorge Stolfi]

PS: The big chunk leaves a trail of dust when falling, I think that's one reason I think it might be something like concrete.

When unit #4 exploded, most of the roof's concrete (or some similar material) was apparently lifted as a unit, and then fell at an angle into the roof steelwork near the north wall. Part of it is still sticking out of the roof. The part that is below the roof can be glimpsed in this photo

http://www.flickr.com/photos/xtcbz/5705937712/in/set-72157626687253144

It is the dark grey "drape" in the background. As others have observed, the "groves" or "folds" visible on that thing are probably the impressions of metal roof panels that supported it.

Seems possible that some of the large objects that were lifted by the explosion of #3 may have been similar to this sheet.

 

[StrangeBeauty]

FYI 6.2 quake not that far away (but 37.6 km (23.4 miles) deep).

http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0003etn.php#details

Should give things a least a bit of jiggle there.