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Japan Earthquake: nuclear plants

by gmax137
Tags: earthquake, japan, nuclear
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Bioengineer01
#9433
Jun9-11, 10:10 AM
P: 123
Quote Quote by sp2 View Post
I just now recalled that I posted this here, a month or so ago (#5257):

<<When TEPCO tells me it's 10% of Chernobyl, I'll assume it's most likely at least 20%, and I'm fairly sure that I at least won't be way high.
Could I be way low? Yeah, I suppose so, but I'll wait for better evidence to support that.
(And, if it *is* way low, there will surely be evidence of that, eventually. Even if it takes a while to seep out, so to speak.)>>

So what did they announce yesterday? That it's more like 20%.

(I'm now working off the assumption it's probably really more like 40%, but we'll see what happens.)
Again, if we apply Markov Chain prediction algorithms using the data already on the thread, worst case versus best case (normally officially supported by TEPCO), you can predict with 80% likelihood that it will be more than 40%, if I fix it at 40% then the probability level comes way down, difference between reported and "true" after two months situations predict a lot worse "true" scenarios. It was a fun exercise... :)
Bioengineer01
#9434
Jun9-11, 10:22 AM
P: 123
Quote Quote by sp2 View Post
Well, it's certainly not thought to be linear.
TEPCO seems to suggest that it's been negligible after the first two weeks, so that initial total roughly equals THE total.

(Not that I necessarily *believe* that, but I think that's the 'official position.')

One thing I'm pretty confident of: the new number will eventually be exposed as nonsense, just like the old number was.

Then all the 'nuclear experts,' who pompously told us again and again that "this is nothing like Chernobyl; anyone who says it is is an idiot" are gonna be even more red-faced than they already are.

And they should be mercilessly held to account for it.
My understanding is that the reported number DO NOT include releases to the Ocean and only air releases and thus the statement that the worse is over. When they consider the true releases to the Ocean, my gross napkin calculations say that they already got Gold!
etudiant
#9435
Jun9-11, 10:33 AM
PF Gold
P: 861
Quote Quote by tsutsuji View Post
According to the Mainichi quote written above at http://www.physicsforums.com/showthr...01#post3347501 the quantity angering the fishermen is only 3,000 tons. I don't really understand what is being planned for the other 7,000-3,000=4,000 tons. Is it so clean that Tepco is allowed to discharge it into the sea by the existing rules ?
Apologies, there was confusion as to the items discussed.
The comment was in response to the Asahi quote in your posting 9418:
The desalinated water will be vaporized in the final step to reduce its volume.
http://www.asahi.com/english/TKY201106080177.html
which appeared to be in the context of the DaiIchi plant water treatment plan.

The 7000 tons at DaiNi seem to be quite an interesting issue in their own right, as the source of their contamination is not obvious. While one can hardly blame TEPCO for wanting to remove this radioactive seawater from their premises, the pattern of disclosure is once again not such as to inspire confidence.
robinson
#9436
Jun9-11, 10:48 AM
P: 201
Since the concern is that it is salt water, no doubt from tsunamis, and that it is contaminated raises a host of questions.
Bioengineer01
#9437
Jun9-11, 11:04 AM
P: 123
Quote Quote by Quim View Post
I am one of the people who don't believe that a hydrogen explosion could have caused the vertical blast we see in the unit 3 explosion, but it is not because I don't believe a hydrogen explosion would be limited in power. To my eyes, the explosion, or the second part of the explosion of unit three, was a vectored blast.

I don't see the "mushroom cloud" as being merely a case of heat rising and carrying with it contaminates from a blast (as is the case in a surface burst nuclear explosion.) I see the vertical cloud as being the actual product of the blast itself. Imagine if you took all the shot out of a shotgun shell, replaced it with a dark powder of some sort and fired it into the air - that effect is what I see in the unit three blast,

I apologize if this explanation sounds too elementary or condescending but there are obviously some here who don't understand the significance of a vectored vertical blast - some force or some structure was responsible for containing the explosive force to a single direction.

The reactor containment structure can be ruled out as the vectoring agent simply because the equipment crane is lying on top of the containment structure with the remnants of the roof laying on top of that. These would not be so if the vertical blast had originated from the RPV or its containment,

The unit three explosion has to be seen as a two part event, a hydrogen blast (which did in fact break steel-reinforced concrete pillars) and a vectored vertical blast.

To jumble these two events and see them both as a single "explosion" would be to ignore the visual evidence.
Hold a second and sorry if it is just another stupid comment on my part, but if it wasn't the containment that vectored the detonation (second phase), for that amount of vertical energy to be generated you'd need fusion level releases of energy from the SPF, since the pool is such a poor vertical vectoring structure. Is it conceivable that the pressure wave from the first detonation could have triggered a fusion reaction? Or am I having a serious senior moment here?
Bioengineer01
#9438
Jun9-11, 11:15 AM
P: 123
Quote Quote by Borek View Post
Discussion on the explosion is already buried deep somewhere in this thread. From what I remember speed of the explosion propagation heavily depends on the shape of the area (walls, columns, any other objects). No idea if that's enough to shape the explosion so that it is mostly vertical (that is, up becomes the path of the least resistance), but who knows.
Seems easy to model using finite elements. From modelling experience, I'd be willing to bet that only a reinforced steel/concrete structure could have contained the blast to only one direction, the forces involved to reach the heights shown in the video are enormous. Which brings me to the second problem, and that is you can also apply inverse modeling and estimate the amount of energy release required to create that size vertical blast vectored by pool of the dimensions of the SFP and you come up with numbers that are too large for hydrogen to generate in a single blast.... The estimation gets even to the ridiculous level if you assume that the detonation came from the top third of the pool. The vertical trajectory is too short and the expansion wave would quickly disperse sideways. I wish I had access to some finite element modeling tools. If somebody has the time, this will make for a quick paper...
Bioengineer01
#9439
Jun9-11, 11:23 AM
P: 123
Quote Quote by zapperzero View Post
At least make an effort to argue or source... such pronouncements add nothing of value.
Source is thread consensus. I'd add to that pronouncement, Hydrolysis as the most likely source for SFP4. Not definitive, but current status of understanding of the most likely scenarios. Definitive proofs will have to wait a lot longer, may be 10 years or more. Solid hypothesis that fit most of the available data is the best we can possibly hope for at this stage. Also, in science, you quickly learn that you can only be proven wrong.
Bioengineer01
#9440
Jun9-11, 11:27 AM
P: 123
Quote Quote by robinson View Post
Back to Power plant two:

http://mdn.mainichi.jp/mdnnews/news/...dm090000c.html

While I don't believe most of what TEPCO reports, much less after it is filtered through the Japanese Government, something clearly went seriously wrong at Daini as well.

What exactly happened there seems shrouded in mystery.
I was wondering the back side of your statement: "Who trusts TEPCO today?" And believe it or not I came up with an answer: "Those who haven't yet sold their shares" :)
robinson
#9441
Jun9-11, 11:50 AM
P: 201
Haha! But out of respect for the forum and the staff, I try to avoid non physics stuff in this thread.
ElliotLake
#9442
Jun9-11, 11:58 AM
P: 11
Quote Quote by razzz View Post
I think that 10% was for a 30 day time frame. The cumulative totals must be near 50% by now and continues to tally up.
Indeed:
Radiation understated after quake, Japan says
Japan said Monday that radioactive emissions from the stricken Fukushima Daiichi nuclear power plant in the early days of the March 11 earthquake and tsunami disaster might have been more than twice as large as a previous estimate, suggesting the accident was more grave than the government had publicly acknowledged. [...]

The agency also said it now estimated that the radioactive release from the plant totaled 770,000 terabecquerels in the first week after March 11. [...]

The agency suggested that the higher emissions estimate was equivalent to only about 10 percent of the radioactive materials released in 1986 by the explosion and fire at Chernobyl [...] But the 770,000 terabecquerels figure in fact comes to about 40 percent of the official Soviet estimate of emissions from Chernobyl. [...]

Officials cautioned that there was a wide margin of error involved [...]
http://www.nytimes.com/2011/06/07/wo...apan.html?_r=1
elektrownik
#9443
Jun9-11, 12:24 PM
P: 296
But they count only air release ? Or water also ?
Bandit127
#9444
Jun9-11, 12:25 PM
P: 189
Quote Quote by NUCENG View Post
If you postulate a fuel air explosion, why do you need a steam explosion too?
Nobody needs a steam explosion. But we do need to try to understand what happened.

If the underpressure was -0.6 Bar(g) the water in the spent fuel pool at about 80C (if I remember correctly) would have very rapidly exceeded its boiling point. Creating rapidly expanding steam.

I can only guess that the effects would have happened firstly at the speed of sound in water (the underpressure) then at that speed in air (expanding steam).
clancy688
#9445
Jun9-11, 12:31 PM
P: 546
Quote Quote by elektrownik View Post
But they count only air release ? Or water also ?
Only air.
mscharisma
#9446
Jun9-11, 12:43 PM
P: 82
Quote Quote by robinson View Post
Back to Power plant two:

http://mdn.mainichi.jp/mdnnews/news/...dm090000c.html

While I don't believe most of what TEPCO reports, much less after it is filtered through the Japanese Government, something clearly went seriously wrong at Daini as well.

What exactly happened there seems shrouded in mystery.
Fwiw, I've gone through the TEPCO press releases (though not the Japanese appendices) relating to Daini, going backwards to, so far, April 13, since it puzzled me that "suddenly" there was a radioactive-water-in-the-basement problem and supposedly ongoing negotiations between TEPCO and government about release into the ocean after some decontamination.

While TEPCO reported a fire on May 27, an air leak on June 8, and an oil leak into the sea on June 9, nothing mentions or deals with accumulated water, radioactive or not, until April 13, although it may very well be in press releases prior to that, which I haven't read yet. In that April 13 press release, it is mentioned that TEPCO has to report to NISA about various aspects of the impact of the tsunami by July 8.

April 13 regarding tsunami impact:
http://www.tepco.co.jp/en/press/corp...1041304-e.html

May 27 regarding fire:
http://www.tepco.co.jp/en/press/corp...1052708-e.html

June 8 regarding air leak:
http://www.tepco.co.jp/en/press/corp...1060808-e.html

June 9 regarding oil leak:
http://www.tepco.co.jp/en/press/corp...1060907-e.html

And then this, also April 13:
http://www.tepco.co.jp/en/press/corp...1041303-e.html
"Regarding the earthquake occurred at 2:07 pm on April 12th (previously
announced in the press release "Plant conditions after the earthquake"
on April 12th), we have been inspecting the plant, however, no trouble on
the plant facilities has been detected
.
The figures indicated at exhaust stack monitors and monitoring posts at
the station boundary are within the usual range, and there is no influence
of radioactivity outside as of now."

Maybe "no trouble" only relates to release of radioactivity?

EDIT: Plant status as of April 11 here (and at least I don't see anything about water in the basement anywhere. ?):
http://www.tepco.co.jp/en/press/corp...s/110411e9.pdf
razzz
#9447
Jun9-11, 12:57 PM
P: 205
Quote Quote by elektrownik View Post
Can someone look at my post about unit 5 here: http://www.physicsforums.com/showpos...postcount=9333
I dont understand still what they were doing there, if the reactor was at 7MPa it must be on ? I dont remember information about scram in unit 5, it was reported always as cold shutdown
I'd like to thank the more experienced and knowledgeable persons for explaining the Unit 5 situation at the time in question. I can only at best give a general response bit since he felt ignored I thought I'd better say something. Can't blame him for wondering why another unit could have failed.

I started reading the .pdf Govt Report to IAEA - June 2011 but can't get past the geology, quake and tsunami data. It just all just seems pointless after those pages.

Edit: I took the time to inquire within the US Geological Survey site by asking a question in which they don't have to respond to but they did as follows...

Hi,

Thank you for your question. Sadly, you read the report correctly. The coast of Japan did sink a bit, in addition to moving in a easterly direction during the earthquake. The subduction at the coastline really reduced the effectiveness of all of the tsunami walls, and of course, the result was devastating.

regards,

Brian Kilgore
US Geological Survey
tsutsuji
#9448
Jun9-11, 01:33 PM
PF Gold
P: 1,220
Quote Quote by mscharisma View Post
Fwiw, I've gone through the TEPCO press releases (though not the Japanese appendices) relating to Daini, going backwards to, so far, April 13, since it puzzled me that "suddenly" there was a radioactive-water-in-the-basement problem and supposedly ongoing negotiations between TEPCO and government about release into the ocean after some decontamination.

While TEPCO reported a fire on May 27, an air leak on June 8, and an oil leak into the sea on June 9, nothing mentions or deals with accumulated water, radioactive or not, until April 13, although it may very well be in press releases prior to that, which I haven't read yet.
The inundation caused by the tsunami wave was mentioned in the April 9 report :http://www.tepco.co.jp/en/press/corp...1040910-e.html with attachment http://www.tepco.co.jp/en/press/corp.../110409e10.pdf where a photograph shows water on the floor of the heat exchanger building. But this water is not supposed to be contaminated.

So I feel surprised by the recent announcement that there is a contaminated water problem at Fukushima Daini.

On the other hand, is it much more surprising than the presence of contaminated water at Fukushima Daiichi unit 6 ? Or at any garden pond or swimming pool in the nearby cities and villages ?
elektrownik
#9449
Jun9-11, 01:36 PM
P: 296
Quote Quote by tsutsuji View Post
On the other hand, is it much more surprising than the presence of contaminated water at Fukushima Daiichi unit 6 ? Or at any garden pond or swimming pool in the nearby cities and villages ?
Yes there is 13500m3 in unit 6 (t/b 9500, r/b 4000) and only 300m3 in unit 5... Torus level is flooded and ground floor around 15cm
tsutsuji
#9450
Jun9-11, 01:44 PM
PF Gold
P: 1,220
Quote Quote by razzz View Post
Edit: I took the time to inquire within the US Geological Survey site by asking a question in which they don't have to respond to but they did as follows...

"you read the report correctly
Can you please provide an internet link to that report ?


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