Japan Earthquake: Nuclear Plants at Fukushima Daiichi

Click For Summary
The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #9,151
elektrownik said:
Can anyone explain me this graph at page 3, there is big jump in I-131 level between 5/27 and 5/31: http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110607e8.pdf

If I remember correctly they had more than usual amount of rain those days or just before it.

The rain washes contamination from debris into the ground and some of that contaminated water may end in the sub-drain pits / sea.

It's not changing underneath the unit #5 and #6 because there is less debris/contamination there.

Why is it not changing underneath the unit #2? Perhaps there is not so much contaminated debris around it because it had a different type of explosion?

This is just my hypothesis. :wink:
 
Last edited by a moderator:
Engineering news on Phys.org
  • #9,152
Bioengineer01 said:
Antisocial, from the lunaticoutpost, who in the past has demonstrated to be one of the most conservative posters in their Fukushima thread, and undoubtedly a current or ex Nuclear worker with expertize in fission and nuclear reactors has just posted the following:
"The individual I know, along with all of her co-workers that were operating weather stations early on are being treated for internal radiation exposure...
...the number of people exposed to considerable danger during the first week is enormous, and many in the JDF are furious with the government and TEPCO for understating or hiding ... Most have had a pretty good idea what went on for the past few weeks, but as it becomes public they can no longer pretend, and the anger is growing. Humiliated is the word I've heard used a lot, and that's a strong word in Japan.

Just to re-iterate, somewhere between 15% and 35% of the core of #3 was ejected up during the explosion. The remainder was forced down. Its assumed the pressure vessel was damaged and this core material is below it now. The explanation I've seen for the modulation of the radiation is that as water seeps into the primary containment, it acts as a moderator/reflector and when it reaches a "critical" depth, it reflects enough energy back into some of the material that it re-achieves criticality. Once this happens the heat created begins driving off the water and the reaction slows. Remember, water between fuel slows the reaction between the fuel, but water surrounding fuel enhances the reaction. The danger here is a large storm could swamp the building and the water could get deep enough that it can't be driven back by the heat, and a potential explosion could result.

One and Two are melted utterly. No one who values their life will come anywhere near those containments for years to come.

Fuel pools are wildcards. ...
Three is a done deal. Nothing at all can be done about it...

... One is believed to have ablated through the floor to some extent based on seismology readings that aren't being made public. There are sensitive sensors all around the grounds listening for underground activity, as well as satellite based imagery used to locate bunkers and tunnels that can image the ground density. 1300C material generates pressure underground that alters the density of the ground, and these changes can be detected and visualized. It's also theorized that this pressure underground is what's driving the water into the other buildings. As hydrostatic pressure builds moving away from the underground source, the water is pushed up and away and is finding the path of least resistance into other buildings. ...there are volumes of real information being created daily. The level of information being made public is the equivalent of what TEPCO would have known in 1975. It's 2011.

..."
http://lunaticoutpost.com/Topic-Nuclear-Power-plant-Onagawa-on-fire-Fukushima-malfunctions?pid=1231435#pid1231435

How plausible is it that the site surrounds are crisscrossed daily by hundreds of workers after having 15-35% of a recently shut down core sprinkled over the landscape?
 
  • #9,153
Borek said:
Any source to that claim, or is it just some post by someone at some forum?


There is a theory which is attractive to some, that the reactor in unit 3 "blew up" on March 14th as at Chernobyl. This theory has nothing to recommend itself to me.
I see no reason to even suspect that the RVP was breached on March 14. If the innards of the RPV had been sprayed about the site as at Chernobyl, the site would be radioactively 'hot" as at Chernobyl and it is clearly not. Further, if one looks at the photo of wreckage of #3, the outline of the equipment crane can be seen lying on top of the area where the containment structure exists, and on top of that, the framework of the roof structure still remains more or less in the same place it had always been. These circumstance could not exist if the reactor "blew up."

IMO the concrete lid(s) for the secondary containment vessel unseated themselves as they were designed to do in the case of overpressure and disgorged a quantity of very hot steam and hydrogen - which initiated the chain of events seen on the video. What happened after that may be debatable but no evidence exists to lead us to think that any contents of the RPV escaped on March 14.

Are you in agreement with this view?
 
  • #9,154
zapperzero said:
How about if you start perusing the thread and don't stop until you finish? Much insight can be gained that way. I myself came in at about page 300, but I don't remember asking for others to do my homework for me.

Yes, most everything that's on houseoffoust was discussed here. Nancy herself was here, actually, discussing photos of #4 reactor. She re-posted most of those photos from Cryptome, btw, so you may as well go to the source from now on and save the time that you would otherwise spend on her commentary and interpretations.

Hey Zapperzero, thanks for the spanking :). I am reading the thread from the start and it is proving VERY illustrative about who is trying to actively minimize the event (now we know the truth a lot more, we don't know how much is still being kept form us), who is posting on an unbiased way and who is pushing to extremes. Very useful exercise! :)
 
  • #9,155
"""no evidence exists to lead us to think that any contents of the RPV escaped on March 14.

Are you in agreement with this view? ""

the strongest evidence of a March 14th breach is to me officialdom's deafening quiet about it and avoidance of pictures.

It is a useful thought tool to push a thought to its logical limit then back up to reasonable-ness.

For an upper logical limit , I find it plausible the vessel head bolts stretched relieving steam but the steam separators/dryers acted as a collander keeping debris inside..

with that as my accepted worst case i can judge other hypotheses against photographs and Jorge's graphs.

Lesser ones i consider,

more radical ones i discard.

but that's just my way of thinking.

old jim :smile:
 
  • #9,156
zapperzero said:
Deflagration vs detonation? Again, you are probably correct. Please, please take the time, do the reading. A study by some Japanese institute wrt this very issue has been recently discussed.

Oh, I followed that in detail, I even tried to get to the source of their assumptions, but unsuccessfully. I am missing up to page 450, although I have been following the event on other threads, and reading this thread on and off, it is just that my technical/scientific background was hungry for more analytical minds with physics/engineering background to discuss with...
 
  • #9,157
Bioengineer01 said:
It is a post from somebody at some forum, but somebody that has posted data in advanced consistently since the event and that has demonstrated to have inside connections with people at Fukushima.

The problem I have with the idea was already mentioned in the meantime. Fuel rods lying everywhere will mean much higher radiation levels than those observed, both in the area and far outside. That wouldn't be something possible to hide. Inside - they wouldn't be able to even take pictures they show (I mean those with people working, investigating, visiting and so on). Outside - too many eyes and sensors - from many countries, from many organizations - vigorously testing air, water, everything.
 
  • #9,158
Testing everything except the steam coming directly out of what used to be reactor building three.
 
  • #9,159
robinson said:
Testing everything except the steam coming directly out of what used to be reactor building three.

I am not writing about tests on site, but tests done far from the site.

Besides, if the steam was seriously radioactive, I guess we would know about it - for the reasons listed in my previous post.

I am not stating TEPCO should not test, I am not stating they are right not publishing results if they do. All I am saying is - I don't believe they could cover something like that for long, when everyone and his dog buys radiation sensors on eBay and sticks them through the window.
 
  • #9,160
Borek said:
Any source to that claim, or is it just some post by someone at some forum?

It up to you to disprove it Borek. What percentage of fuel assemblies have to vaporize and release into the atmosphere to cause the amount of fallout so far discovered locally and worldwide? You owed it to the people who are not as smart as you.
 
  • #9,161
Desperate attempts by plant workers to vent pressure to prevent the containment vessels from bursting repeatedly failed. Experts have said the delay in venting was a primary cause of explosions that further damaged the reactors and spewed huge amounts of radiation into the air. The report also noted the outermost containment buildings should have had vents to prevent a series of explosions at three units.

The melted cores and radiation leaks have irradiated workers, including two control room operators whose exposures have exceeded the government limit.

http://news.yahoo.com/s/ap/ap_on_bi_ge/as_japan_earthquake
 
Last edited by a moderator:
  • #9,162
Borek said:
The problem I have with the idea was already mentioned in the meantime. Fuel rods lying everywhere will mean much higher radiation levels than those observed, both in the area and far outside. That wouldn't be something possible to hide. Inside - they wouldn't be able to even take pictures they show (I mean those with people working, investigating, visiting and so on). Outside - too many eyes and sensors - from many countries, from many organizations - vigorously testing air, water, everything.

I hope that you are right, although given that I am reading the thread from page 1 on right now, with the benefit of today's knowledge and knowing of some recognized TEPCO's confessions and exposed coverups. I am finding that the worst case scenarios presented from the beginning were the most accurate ones, and the vanilla ones were off by a long shot. If I didn't think it would be considered inappropriate I would be re-posting some of the statements made at the beginning of this thread that would make us feel very gullible and infantile in our willingness to believe what we were being told. I highly recommend re-reading even for those of you that have been here all along... Very educative...
 
  • #9,163
Calm down with ejected fuel idea, it is simple - if it would be ejected all peoples which were working there would die in not more than one day...
 
  • #9,164
razzz said:
It up to you to disprove it Borek. What percentage of fuel assemblies have to vaporize and release into the atmosphere to cause the amount of fallout so far discovered locally and worldwide? You owed it to the people who are not as smart as you.
You forgot the snark tag ;)

Seriously, it is up to the claimant to prove their claims, not the other way around.

However, I do have a question related to this that I think will help with the repeated statements about reactors blowing up, reactor lids being blown off, etc.

I don't recall seeing an estimate on this thread of radiation levels if, indeed, there were fuel rods lying about the site. For example, what would the Sv/hr readings look like for one fuel rod from #3 look like if it were lying out on the grass? I don't have a clear concept of the magnitude. Thanks.
 
  • #9,165
razzz said:
It up to you to disprove it Borek. What percentage of fuel assemblies have to vaporize and release into the atmosphere to cause the amount of fallout so far discovered locally and worldwide? You owed it to the people who are not as smart as you.

This is neither how science nor logic works. The onus of proof is on those making claims, not those skeptical of the claims.
 
Last edited:
  • #9,166
razzz said:
It up to you to disprove it Borek. What percentage of fuel assemblies have to vaporize and release into the atmosphere to cause the amount of fallout so far discovered locally and worldwide? You owed it to the people who are not as smart as you.

It's not up to anyone to disprove anything in the absence of solid data - and nobody (even the workers at Tepco) have the data to say what happened to the core in Unit 3.

I believe your post (unless others see it as 'banter') is against the spirit of this scientific forum.
 
  • #9,167
Bioengineer01 said:
If I didn't think it would be considered inappropriate I would be re-posting some of the statements made at the beginning of this thread that would make us feel very gullible and infantile in our willingness to believe what we were being told.

I know just what you mean. But it would be appropriate for the political threads, this one has quite enough with the speculations about what happened, is happening, and might happen.
 
  • #9,168
razzz said:
It up to you to disprove it Borek. What percentage of fuel assemblies have to vaporize and release into the atmosphere to cause the amount of fallout so far discovered locally and worldwide? You owed it to the people who are not as smart as you.
Well, such a calculation would not be understood by those people. I believe that the accident has been and still is downplayed a lot be the Japanese . But ejection of a significant part of the reactor core? Never! Look at Chernobyl. Look at the pictures and films. You can see flashes on them everywhere - flashes from the ambient radiation. These were all cameras without electronics. I bet a modern electronic camera would have failed immediately. Look at the firemen who were fighting the fire immediately after the explosion. They all became sick after some hours and most of them died after a month or so.

Whatever exploded in unit #3 - the core must have stayed in the containment.
 
  • #9,169
westfield said:
Here is a short clip of the steam emanating from the north side of the containment "void".

At other times it's been more active like in this poor quality image

http://i1185.photobucket.com/albums/z360/fukuwest/misc/sfpinRB302.jpg

Those releases appear to me to be coming from the containment structure, although; I will agree that there is a possibility they are coming from north of the containment.

But there is nothing that i know of to the north of the containment structure that could be a source of steam release, except steam from a leak or broken pipe lower in the containment structure which finds its way out there.

But that still leaves the two sources of steam as being the containment structure and the SFP.

What do you think?
 
  • #9,170
joewein said:
Yes, there's a nearby dam. That's where they got their freshwater from.

Which once again points out how unfortunate it is that we are lacking a poster knowledgeable of the subject of geology.

It simply can't be true that the underground rock formations, water tables and streams at the Fukushima site are an unknown.

Somebody did the engineering for that dam.
 
  • #9,171
Quim said:
Which once again points out how unfortunate it is that we are lacking a poster knowledgeable of the subject of geology.

It simply can't be true that the underground rock formations, water tables and streams at the Fukushima site are an unknown.

Somebody did the engineering for that dam.

I cross posted a question on the Earth PF about mudrock as bedrock toget a geological input. The consensus there was that it could support a large structure as a nuclear plant. It is an idea.
 
  • #9,172
With the release of radioactive material, the question of where is comes from is not out of question. More tolerance is given to deformed roofing truss theories than legitimate real time tragedies.

Besides that, the majority of people are not chronically moronic just passive to a fault, since being ill-informed or mis-informed and as such take irrational action due to their lack of knowledge or lack of meaningful information.

Science would conclude not allowing exposure to the masses a process that once started couldn't be stopped, discovered via experimentation. Enter politics or the military.
 
  • #9,173
Bioengineer01 said:
"In its report, Japan's government informs the IAEA that fuel is assumed to have melted down and may have burnt through the reactor pressure vessels of units one, two and three and into their outer steel containment vessels."
http://news.ph.msn.com/top-stories/article.aspx?cp-documentid=4915540

English version of the report is here:

http://www.kantei.go.jp/foreign/kan/topics/201106/iaea_houkokusho_e.html"

...no attachments!
 
Last edited by a moderator:
  • #9,174
Quim said:
Which once again points out how unfortunate it is that we are lacking a poster knowledgeable of the subject of geology.
As I said before, it's not that we don't have a geologist. It's that we don't have any geological information. A map would be a good start.
 
  • #9,175
biffvernon said:
As I said before, it's not that we don't have a geologist. It's that we don't have any geological information. A map would be a good start.

The geologist would bring the information, and point to sources of information, both raw and compiled.

Information on the geology and underground water exists for that location.

I am convinced of that.
 
  • #9,176
jim hardy said:
""the strongest evidence of a March 14th breach is to me officialdom's deafening quiet about it and avoidance of pictures.

I can wholeheartedly agree with that.
But it is also the only evidence for a breach of RPV containment that I can think of.

Maybe there was something else about the March 14th event that they would just as soon not have known.
 
  • #9,177
westfield said:
Indeed. How do we rule out that the hydrogen wasn't already in RB #4 via common ducting before RB #3 exploded?
Can we rule out other alternate ducting routes between the buildings?
I was hoping someone would know what other potential SGTS pathways there are between the buildings, if any.

Fwiw, I also find the SGTS theory a bit implausible and SFP #4 fuel more obvious but I have no real background or proof to back my feelings, just seems unlikely (and unsafe) that not one of the many valves in the SGTS would be closed on LOP, unlikely there would be no "backflow" prevention devices given the sort of gases they are moving around and unlikely that the gas made its way via their shared lines PAST the stack instead of up and out of the stack.

However it seems difficult to definitely rule out the possible SGTS communication between buildings unless we have intimate knowledge of all the potential ducting pathways between the buildings.

I am anxiously awaiting more information like everyone I guess.

My reasoning that the Hydrogen was not in unit 4 already is qualitative. The videos of the unit 3 explosion show a large fireball. If there was hydrogen gas flowing from unit 3 to unit 4 wouldn't the flame front follow that path as well? But we know from photographs that the building 4 damage was sometime overnight well afrter the number 3 explosion.

A second reason is that in order to get from unit 3 to unit 4 there would have had to be a difference in pressure, but unit 4 with the fuel pool boiling would probably have had a higher pressure than unit 3. If you look at the pipe routing, the gas would have had to move downward through the external piping from unit 3 through the external piping in unit 4, through the charcoal filters and HEPA filters in unit 4 against that pressure.

I can't think of any other system or shared piping that would have been a pathway between units. The 4 units appear to share an offgas stack from the turbine buildings, but if you look there are four pipes at the top of that stack. It surprises me that they didn't route separate pipes from the two units to the top of the SBGT stack, but it appears they did come together at the base of the stack.

Once unit 3 exploded it is even less likely that the unit 3 building could hold pressure to force hydrogen to unit 4, even if its piping was intact.

You are right that there may be some design details we haven't seen and I can't say my arguments rules out a pathway to a certainty. But we are getting close to betting odds.
 
  • #9,178
StrangeBeauty said:
You forgot the snark tag ;)

Seriously, it is up to the claimant to prove their claims, not the other way around.

However, I do have a question related to this that I think will help with the repeated statements about reactors blowing up, reactor lids being blown off, etc.

I don't recall seeing an estimate on this thread of radiation levels if, indeed, there were fuel rods lying about the site. For example, what would the Sv/hr readings look like for one fuel rod from #3 look like if it were lying out on the grass? I don't have a clear concept of the magnitude. Thanks.

It would very much depend on the history of the fuel rod, if it is brand new it is not very radioactive, but it becomes increasingly more radioactive during use, reaching a peak when it is time for it to be taken out of service and placed in the sfp. Once there, its radioactivity will again slowly wane over many years.

However, just to get some idea of the magnitude of activity we could be looking at, according to the NRC, the surface radioactivity of a spent fuel rod still exceeds 100 Sv/h after having been stored ten years in the sfp.
 
  • #9,179
Quim said:
Those releases appear to me to be coming from the containment structure, although; I will agree that there is a possibility they are coming from north of the containment.

But there is nothing that i know of to the north of the containment structure that could be a source of steam release, except steam from a leak or broken pipe lower in the containment structure which finds its way out there.

But that still leaves the two sources of steam as being the containment structure and the SFP.

What do you think?

I don't think you are actually in any disagreement with people that have responded about this point. When they are saying north of containment they are not implying that something to the north of containment is the source of the steam, but rather that steam has been seen escaping from the north side of containment.

I posed some pictures of this stuff a while back, taken from early video, because I was interested in whether this would count as a 'containment crack' which one or two reports referred to some while ago, suggesting that there was visual evidence of such a crack. I was speculating as to whether, if such reporting was accurate, the images were not unknown to us but could have been shown in something we'd already seen. Later I returned to the same footage because I was interested in the possibility that we might just be able to make out a line where the top of the semi-circular reactor containment plugs meets the removable concrete wall that separates the equipment pit/pool from the area directly above the reactor.

attachment.php?attachmentid=35370&d=1305058230.jpg
 
  • #9,180
Bioengineer01 said:
I am wondering if these pictures of Reactor 3 and the analysis that goes with them have been discussed in the thread. They seem very informative to me. Comments?

http://www.houseoffoust.com/fukushima/R3.html

It was all discussed here ad infinitum. That's not to say further information wouldn't be welcome. A new batch of photos would re-ignite the conversation, but every image and video publicly available has been dissected at length.

On another note, Foust's enlarged pictures don't really reveal anything new. She posts some interesting information once in a while. Can't say much about her analyses, though.
 
Last edited by a moderator:

Similar threads

  • · Replies 12 ·
Replies
12
Views
49K
  • · Replies 41 ·
2
Replies
41
Views
5K
  • · Replies 2K ·
60
Replies
2K
Views
451K
  • · Replies 5 ·
Replies
5
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
20K
  • · Replies 763 ·
26
Replies
763
Views
274K
  • · Replies 38 ·
2
Replies
38
Views
16K
Replies
6
Views
4K
  • · Replies 4 ·
Replies
4
Views
11K