robinson said:Of course, but that isn't what is supposed to have happened
hope i saved right link, it's a Danish studyHydrogen Problems Related to
Reactor Accidents
etudiant said:Is it even realistic to think of evaporating 100,000 - 200,000 tons of water, apart from the contaminated steam aspect?
Seems to me they might need to restart unit 5 or 6 to supply that kind of heating.
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... :)sp2 said: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.)
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!sp2 said: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 going to be even more red-faced than they already are.
And they should be mercilessly held to account for it.
tsutsuji said:According to the Mainichi quote written above at https://www.physicsforums.com/showthread.php?p=3347501#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 ?
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?Quim said: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.
Borek said: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.
zapperzero said:At least make an effort to argue or source... such pronouncements add nothing of value.
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 said:Back to Power plant two:
http://mdn.mainichi.jp/mdnnews/news/20110608p2g00m0dm090000c.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.
Indeed:razzz said: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.
http://www.nytimes.com/2011/06/07/world/asia/07japan.html?_r=1Japan 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 [...]
NUCENG said:If you postulate a fuel air explosion, why do you need a steam explosion too?
elektrownik said:But they count only air release ? Or water also ?
robinson said:Back to Power plant two:
http://mdn.mainichi.jp/mdnnews/news/20110608p2g00m0dm090000c.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.
elektrownik said:Can someone look at my post about unit 5 here: https://www.physicsforums.com/showpost.php?p=3346232&postcount=9333
I don't understand still what they were doing there, if the reactor was at 7MPa it must be on ? I don't remember information about scram in unit 5, it was reported always as cold shutdown
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
mscharisma said: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.
tsutsuji said: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 ?
razzz said: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
tsutsuji said:The inundation caused by the tsunami wave was mentioned in the April 9 report :http://www.tepco.co.jp/en/press/corp-com/release/11040910-e.html with attachment http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/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 ?
Bioengineer01 said: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!
SteveElbows said:I see that according to latest plant parameters, they measured unit 4 fuel pool temperature at 19:52 on the 8th June and it was 86-88 degrees C.
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/11060906_table_summary-e.pdf
mscharisma said:Especially since it is now claimed to be contaminated in a most illogical fashion with the source unknown, I find the overall picture the silence paints rather suspicious. And I'm hoping that you scientific-minded folks here will keep an eye on it all.
etudiant said:With all respect, that theory seems to me intensely implausible.
The explosion in reactor 3 was a coarse detonation, leaving huge chunks of stuff flying through the air.
Had it tossed out bits of the fuel from the SPF, one would expect fuel rod assemblies among the debris, not microscopic traces so minute that it takes effort to distinguish them from bomb test fallout.
Imho, the scenario of vapor leaks from the molten fuel in reactor 1 fits the data much better.
Joe Neubarth said:I saw a small segment of a video of the SFP for Reactor Three, and it looked like the Fuel assemblies were in place with a lot of debris on top of them. Has anybody seen anything else that would indicate that the spent fuel was exploded out of the pool?
elektrownik said:You mean reactor 4 ? In unit 3 we didnt saw fuel because of big debris...
SteveElbows said:I remain open-minded about this, but I won't go as far as to say that the official claim is totally illogical.
By this I mean that I probably should not be surprised if I give a nuclear power plant a bit of a wash with tsunami water, I would expect a variety of 'normal' low level contamination from certain parts of the plant could well end up in that water.
To significantly reduce the plausibility of this possibility, I think we would need to see water that is much more severely contaminated than the sorts of numbers they have mentioned so far indicate is the case here?
I used Mice and Men's link http://min.us/mvoVGLP" for the Govt Report to IAEA - June 2011 which is being referenced and quoted now as 'official.' The quake and other related data is in Chapter or Heading III were interesting to me.tsutsuji said:Can you please provide an internet link to that report ?
No disrespect meant! Just trying to break the ice, same as if we were discussing around a table :)robinson said:Haha! But out of respect for the forum and the staff, I try to avoid non physics stuff in this thread.
rowmag said:My personal opinion is that most of the text does not seem very interesting unless one is a hardcore civil engineering otaku. The juicy bits of relevance for this thread are mostly in the illustrations, as you note.
Try "まえがき."
Joe Neubarth said:The debris was scattered on top of the fuel assembly tops. They all looked in place to me. The rectangular patterns are quite distinctive. The only thing is that we only saw about two - three square feet of the top of the assemblies. The key in the video is to look quickly at the very beginning. As the bubbles come up and block the lens you can see the pattern of the top of the assemblies at the top and left of center. That rectangular pattern was consistent with the pattern in the reactor 4 SFP.