Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Quim]

That would come out close to zero, I think. It is indeed a borderline case, but the smallest imaginable critical mass would have consumed fissionable material such as to become subcritical after just one 'neutron generation'.

That sounds more like NUCENG's "subcritical neutron amplification."

If it become subcritical after just one neutron generation how could you consider it self-sustaining?

 

[maddog1964]

You guys do realize that there's a thread which deals specifically with the Unit 3 explosion? How about you talk about that topic over there?

could you please list the link to that thread. ty

 

[MadderDoc]

That sounds more like NUCENG's "subcritical neutron amplification."

If it become subcritical after just one neutron generation how could you consider it self-sustaining?

I did say, this is a borderline case.

 

[Bioengineer01]

@ Bioengineer01


Fine, go and do the exploration... I would suggest you first explore the possibility that there is NO inconsistency in the thermal signatures of the SFP versus the visible surface of water in the reactor vessel.
.

Absolutely agree and I am not wasting any time on conspiracy theories. That is why I am reading the thread and enjoying the discussion and trying to make sense and find an explanation to the apparent inconsistency. I've done myself lots of IR for biological reasons, it is an extremely useful tool, in my post, I was just trying to explain why people are still discussing this. Nothing less, nothing more.

 

[robinson]

http://www.tepco.co.jp/nu/f1-np/camera/index-j.html

While it would be hard to imagine a worse camera set up, even so you can still see the constant steam coming out of the buildings. Is there any plan to do anything to even find out what is happening inside building three?

Like stick some cameras in there? How long do you simply just let a nuclear pile of crap steam away? With out even knowing where the steam is coming from. or what is in it.

 

[Bioengineer01]

I note your tremendous artistic talent in replying. Thank you.

I have always thought of is as ping pong balls and bowling balls. Ping pong balls (neutrons) will bounce off of heavier atoms (bowling balls) without losing energy, but will bounce off of Hydrogen atoms and impart some of their energy to the Hydrogen. I guess eventually they can be turned around.

I read early on that the salt produced by the evaporation of sea water could have a significant effect on this interaction from experts at the NRC that advised Japan to stop the seawater injection. But I never found it in written news, my assumption was that it could help form a crust around the Corium and any cracks or fissures that it may develop and make the process of heat extraction more difficult, but now I wonder if that same crust of salt would not participate in neutron slowdown and reflection. Just a thought, anybody? Can anybody add clarity to this?

 

[MadderDoc]

Absolutely agree and I am not wasting any time on conspiracy theories. That is why I am reading the thread and enjoying the discussion and trying to make sense and find an explanation to the apparent inconsistency. I've done myself lots of IR for biological reasons, it is an extremely useful tool, in my post, I was just trying to explain why people are still discussing this. Nothing less, nothing more.

I agree the heat signature from the reactor well is 'strange'. Generally this signature has had an IR measured temperature close to 30^oC, and this even on early mornings where ambient temperature has been only 0-5^oC.

Naturally under such circumstances we are unlikely to be measuring the temperature of the water surface, but rather the temperature of condensed steam hanging over it. And this would imply that the water surface must be even _warmer_ than 30^oC. I too cannot imagine how water can be kept this warm in the reactor well throughout many days during March and April, with cold nights and never a ray of sunlight hitting it. I certainly would like to know how I can keep the roof of my house cosily warm throughout winter without a considerable heat source underneath it ..

 

[Jorge Stolfi]

If it become subcritical after just one neutron generation how could you consider it self-sustaining?

By that criterion criticality is impossible, since as the fuel is consumed the value of k will decrease until the chain reaction stops.

The k parameter and the critical/subcritical distinctions are drastic simplifications of reality. If you look too closely, the k parameter is not a well-defined quantity, and criticality becomes a fuzzy concept.

On the other hand, note that some chain fissions should occur at a steady rate even if k < 1, and should boost the spontaneous neutron emission rate by the factor 1/(1 - k). For k = 0.8, for example, the total neutron production (spontaneous + fission) should be ~5 times the spontaneous rate. That is "sustained" in the sense that the fission reactions keep happening at the same rate as long as one can consider the composition of the mass constant.

I would guess that even with a boost of x5 or x20 over the spontaneous rate, the heat generated by fission will be negligible compared the normal decay heat of half-used fuel. But what about the radiation hazard?

 

[Pu239]

Conditions in the night are such that it looks steaming every day. My bet is that is mostly a matter of local weather - humidity and temperature changes. Fog clouds are moving in and out of the light, which makes the picture dramatic.

I have looked at the live feed at several occasions, never longer than just a few minutes, usually after someone raises alarm - and each time it looks the same to me.

Edit: it occurred to me that compression artifacts look like a dynamic smoke/steam cloud as well. Thats typical in low light conditions - dark, large spots with slight color gradient look like moving even if the image is still. It can look as a dynamic steam motion, even if the real situation is quite stable.

I gather nobody actually saw the large release of steam - very large - last night. We know it is steaming every day but this was far above the normal. Definitely not fog or clouds. This was a large, fast moving vertical plume of smoke coming directly from #4 - top of roof. It eventually billowed out and clouded everything - then, at that stage it was mistaken by many observers for fog or rolling cloud. Not. (Think of looking at a smoking chimney in cloudy or possibly foggy conditions - smoke is grey, fog is white).

Just before that everything was clear (but dark) with the usual lit-up reactors. The plume was studied carefully [by myself and others] as it grew from a whisp at the top of #4 to a massive all-engulfing cloud. Emergency vehicles arrived soon after, with flashing lights.

Have heard nothing since.

TEPCO LIVE CAMERA

http://www.tepco.co.jp/en/nu/f1-np/camera/index-e.html

 

[StrangeBeauty]

I just saw a white and black spotted DOG walk past the TEPCO webcam , it stopped and even looked into the cam for a sec !...

Could it be that the white spots are neutron reflectors and the black spots neutron absorbers creating a moderating field for recriticality?!

I did say, this is a borderline case.

Yes! It must have been a borderline collie!








Apologies for the physics humor. ;)

 

[robinson]

http://flyingcuttlefish.wordpress.c...-fire-right-now-live-cam-shows-lots-of-smoke/

Second video shows a time lapse where the steam.smoke is obvious. Not from last night, but still, this is a regular event at night.

 

[StrangeBeauty]

I gather nobody actually saw the large release of steam - very large - last night...

A lovely sequence of a marine fog bank rolling in with lots of video compression artifacts thrown in.

http://flyingcuttlefish.wordpress.c...-fire-right-now-live-cam-shows-lots-of-smoke/

Second video shows a time lapse where the steam.smoke is obvious. Not from last night, but still, this is a regular event at night.

Yes lots of "steam" whenever the dewpoint gets close to the air temperature (as it often does at night).

I realize that something (more) horrible could happen with SPF4 or any of the other units, but these frequent steam displays are not it. The building is not on fire. The building is not smoking. At least not now or all the other times that such has been claimed.

This is just the same, constant steaming of the SPF made more visible by local weather conditions. I am not saying to drop vigilance in observing, but I think we're getting way too many false alarms now. I imagine that most of our esteemed thread readers and participants are just skipping over the constant stream of "fire/smoke at SPF4/#3" posts and will skip over a legitimate problem if it should arise.

 

[Morbius]

The k parameter and the critical/subcritical distinctions are drastic simplifications of reality. If you look too closely, the k parameter is not a well-defined quantity, and criticality becomes a fuzzy concept.

Jorge,

Yes - it's fuzzy when you're just hand-waving about the definition.

However, in terms of the mathematical definition of "k", the k parameter is very well defined. It is as well defined as any other eigenvalue of an eigenvalue equation which is what the critical problem really is.

Dr. Gregory Greenman

 

[robinson]

Yes lots of "steam" whenever the dewpoint gets close to the air temperature (as it often does at night).

No, when the dewpoint is right you can see it, but there is always steam/water vapor coming out of all four buildings. 24/7

If only there was a way to measure what is in it. It could give a clue as to what is happening.

 

[StrangeBeauty]

No, when the dewpoint is right you can see it, but there is always steam/water vapor coming out of all four buildings. 24/7

Of course it's 24/7. I meant it becomes more visible under those conditions and that's when people have been "crying wolf" about fires/smoke.

If only there was a way to measure what is in it. It could give a clue as to what is happening.

I completely agree with that. The compressed video is just too misleading/imprecise to tell anything definitive.

 

[Pu239]

A lovely sequence of a marine fog bank rolling in with lots of video compression artifacts thrown in.

Yes lots of "steam" whenever the dewpoint gets close to the air temperature (as it often does at night).

I realize that something (more) horrible could happen with SPF4 or any of the other units, but these frequent steam displays are not it. The building is not on fire. The building is not smoking. At least not now or all the other times that such has been claimed.

This is just the same, constant steaming of the SPF made more visible by local weather conditions. I am not saying to drop vigilance in observing, but I think we're getting way too many false alarms now. I imagine that most of our esteemed thread readers and participants are just skipping over the constant stream of "fire/smoke at SPF4/#3" posts and will skip over a legitimate problem if it should arise.

Have a look at the following videos. I'll drop this topic very shortly, but I do want some kind of corroboration, given that this board's topic is: Physics Forums > Engineering > Nuclear Engineering > Japan Earthquake: nuclear plants.

This was not

- a false alarm
- one of the many false alarms
- one of the many frequent steam displays

It was a *massive* and significant steam/vapour display that started with a clearly visible vertical emission of vapour, then blotted out all the other reactors - starting around 2:15 in the first video below. Also look at the 10 second mark in the second video. They look very much like explosions to me:

Here's the video:
2011.06.14 00:00-01:00 / 福島原発ライブカメラ (Live Fukushima Nuclear Plant Cam)
http://www.youtube.com/fuku1live#p/u/9/k-EDceWFovc

2011.06.14 01:00-02:00 / 福島原発ライブカメラ (Live Fukushima Nuclear Plant Cam)
http://www.youtube.com/fuku1live#p/u/8/fg8yGBhoLxU

 

[Pu239]

You'll notice that actually #3 and #4 are steaming in those videos.

 

[biggerten]

I think you saw three things -

1) SFP 4 steaming.
2) Followed by a fog bank rolling in.
3) The arrival of a wide load caravan with one of those oversized tanks they're bringing in at the rate of 4 or 6 per day.

 

[Pu239]

No fog that day. We checked the weather - realtime. Conditions were cloudy.

Unless fog starts inland from the top of a building and rolls out to sea?

Also, you'll see two vertical plumes - one from #3 and one from #4.

You'll also see flashes of light within those plumes - but, have to watch all of the video.

You'll also notice an explosion 10 sec in on the 2nd video from #4, or the shared spent fuel area.

I see no caravan. Or gypsies.

Time to drop this topic I guess.

 

[quark42]

I live along the central California coast. I'm very acquainted with the behavior of fog and lights at night. I also have years of photography experience (an avocation along with an engineering vocation). Also, being a pilot with com/inst ratings, I have a very good understanding of what happens when the temp/dew point spread narrows and its affect on water vapor visibility, i.e. clouds.

My opinion on the "visible vertical emission of vapor" is an illusion caused by the lighting of the exhaust tower behind forming fog. The tower is exactly behind where the column of vapor "appears".

Just my two cents worth, anyway.

It does, however, bare repeating the importance of checking the temp/dewpoint spread when considering the possibility of anomalous emmisions from the reactor buildings.

 

[Pu239]

I'm well aware of the tower and the optical illusions thereof. Yes, the vertical tower can be mistaken for a vertical plume of smoke, but this isn't what I'm talking about at all.

Take another look at your "fog". This is the third hour of the event:

2011.06.14 03:00-04:00 / 福島原発ライブカメラ (Live Fukushima Nuclear Plant Cam)
http://www.youtube.com/fuku1live#p/u/6/vThV0k3IZEc

I'm also interested in the explosions within that "fog". They occur in several places, e.g. 10 sec in on hour 01:00-02:00.

Otherwise, it seems I'm beating a dead horse here, no takers. Over to video forensics I guess.

 

[robinson]

Fog does not start up high like we see in the videos. It also doesn't just come in at one location. If it was fog, which we can see in other videos, it looks completely different than those events.

 

[quark42]

Well, I do see puffs of coming out of the reactor buildings, but they don't look to me like explosions. Just warm water vapor. But like you say, the ex-horse has been well beaten.

 

[Jorge Stolfi]

Jorge, Yes - it's fuzzy when you're just hand-waving about the definition.

However, in terms of the mathematical definition of "k", the k parameter is very well defined. It is as well defined as any other eigenvalue of an eigenvalue equation which is what the critical problem really is.

The k parameter of the differential equation is defined with matematical precision of course.

The drastic simplification is in the modeling of the 3D physical situation (with spatially variable distributions of materials and neutrons, multiple neutron energies and directions, compressibility and material flow, etc.) by that single ordinary first-order single-valued linear differential equation. The fuzziness surfaces when one tries to explain what that single variable stands for. All the best,

 

[Jorge Stolfi]

2011.06.14 00:00-01:00 / 福島原発ライブカメラ (Live Fukushima Nuclear Plant Cam)
http://www.youtube.com/fuku1live#p/u/9/k-EDceWFovc

2011.06.14 01:00-02:00 / 福島原発ライブカメラ (Live Fukushima Nuclear Plant Cam)
http://www.youtube.com/fuku1live#p/u/8/fg8yGBhoLxU

2011.06.14 03:00-04:00 / 福島原発ライブカメラ (Live Fukushima Nuclear Plant Cam)
http://www.youtube.com/fuku1live#p/u/6/vThV0k3IZEc

My two cents: it is tantalizing, but not quite convincing.

I believe that much of the shivering and "boiling" motion we see in the large "steam" cloud, for example on the North side of #2, is just camera noise (which gets more severe in the darkest part of the night, when the camera gain gets automatically pushed all the way up); compounded by MPEG compression artifacts (curs'd be he who invented that format!). Notice that the shivering disappears completely when sunlight begings to increase again at the end of the third video.

My brain cannot easily filter out that shivering noise, but I suspect that without it the big cloud would be largely static, and the movie would look very much like an ordinary fog bank gradually coming in from the sea and engulfing the steam plumes from the reactors. Note that he fog would be invisible until it gets above the reactors, where it becomes lighted by the spotlights.

As for the "explosion" at 03:10, its location does not match any of the reactors. It looks like someone swung the beam of a spotlight (or a strong headlight) acoss the webcam.

 

[Pu239]

A+.

You got it.

 

[Pu239]

Fog does not start up high like we see in the videos. It also doesn't just come in at one location. If it was fog, which we can see in other videos, it looks completely different than those events.

A+, with honours.

:D

 

[clancy688]

could you please list the link to that thread. ty

https://www.physicsforums.com/showthread.php?t=505630

----

Why don't you guys make a "Where's Wally?" thread about Unit 4. There you can point out what you're seeing or not seeing or what you think you're seeing at Unit 4 all you like.

 

[Borek]

Take another look at your "fog". This is the third hour of the event:

Note one important thing: in all cases it starts with a buildings steaming (they do it all the time) but then they are covered with a huge cloud of fog that comes from the outside - it is not that buildings "puff" a large cloud from the inside, cloud appears first high above the buildings and then covers them as it moves in the direction of the land (obviously it comes from the sea).

And I agree with Jorge that those flashes are just a light scattering by the fog - could be something like flashlight or headlight, but some look just like cloud of fog entering the beam from the street lamp or reflector. You don't see the beam, so you think the place is dark, but when fog comes in the beam it becomes source of scattered light - and it looks like if some light source appeared out of nothing.

In the place where I live fog is nothing unusual - and knowing how it looks here, I don't see anything unusual on these videos.

 

[SteveElbows]

The webcam did look a bit more interesting than usual during this time period, but when all is said and done it looked extremely likely to be a weather event to me. There was rain in the area around this time, according to online rain radar, and in later footage we can actually see some water in the foreground drying up over time.

As for 'explosions', most nights there are a variety of flashes, some of which seem most likely to be caused by vehicle headlights.

According to information on planned operations, there would have been unit 4 pool spraying for many hours during the afternoon and evening before this footage.

I suppose we have to be careful not to become complacent, but at this point its all been false alarms and a failure to take weather into account.

 

[joewein]

By which route/medium/mechanism should the majority of total air releases from the plant have escaped from unit2?

Several weeks ago I heard that the contamination in the Namie / Iitate region to the NW of Fukushima Daiichi was linked mostly to emissions from unit 2. Researchers reviewing SPEEDI predictions realized that the rain and snow that brought down most of the radioactivity there must have picked up the radioactivity at Fukushima Daiichi around the time the suppression chamber blew up, according to a late night documentary I watched on NHK.

The suppression chamber explosion in unit 2 on the morning of March 15 sounded like bad news at the time as it was a clear breach of the containment. The presence of the containment supposedly was the reason why Fukushima was not going to be another Chernobyl (the main reason I decided that same day to get out of Japan for a while were the #4 SFP problems though).

The reactor pressure vessel vents into the containment when pressure gets too high and it does that through the water in the torus, which acts as a fairly effective scrubber, catching most of the radioisotopes other than noble gases. Consequently, when TEPCO had difficulties venting the containment in unit 2 later on and pressure far exceeded design limits, leading to the suppression chamber bursting, there must have been a lot of volatile substances in the torus already.

I would be very interested in getting a clearer picture of exactly what events at Fukushima Daiichi match up with the various spikes in radioactivity in these charts, especially on March 15 and 16:
http://fleep.com/earthquake/

I have no clear image either what path any release would take from the torus. Would the radioactivity have to climb up through the stairwells between the floors? Radioactivity inside the #2 reactor building did not seem to be vastly different from levels in #1 when TEPCO first sent in robots and then people.

We do know that one panel was blown off the side walls near the #2 SFP.

 

[SteveElbows]

I would be very interested in getting a clearer picture of exactly what events at Fukushima Daiichi match up with the various spikes in radioactivity in these charts, especially on March 15 and 16:
http://fleep.com/earthquake/

I have no clear image either what path any release would take from the torus. Would the radioactivity have to climb up through the stairwells between the floors? Radioactivity inside the #2 reactor building did not seem to be vastly different from levels in #1 when TEPCO first sent in robots and then people.

We do know that one panel was blown off the side walls near the #2 SFP.

Narrative in report to IAEA mentions the high radiation levels on site on the 15th, and although they have an issue with not knowing how much this may have been caused by unit 4 explosion/fires as opposed to reactor 2 s/c failure, it looks like reactor 2 is given credit for most of this.

The same narrative mentions further releases on March 16th, both from reactor 2 & reactor 3. I will be looking at the detail of this at some point this week.

I have sifted through loads of SPEEDI data, and for March 15th the wind is taking stuff south, but by the afternoon it is taking stuff north west, and prediction models start to resemble the actual map of contamination/expanded evacuation zone.

Reactor 3 explosion does not generate interesting SPEEDI data at all, because the wind is mostly taking stuff out to sea on this date.

Reactor 1 explosion also causes SPEEDI to project a plume that strongly resembles the north-west contamination zone, so its a bit hard for me to state how much of the contamination in this area comes from 2 rather than 1.

The panel that is missing from reactor 2 building is not by the fuel pool, rather it is close to the floor area above the reactor itself. There also remains some ambiguity as to whether this was blown off or removed deliberately. Official information states that it was removes as a result of explosion at 3, but that does not tell us with 100% clarity whether the explosion at 3 caused it to fall, or whether they removed it because of the explosion at 3, to prevent the same thing happening at 2.

As for pathway of release, I am not sure. In the narrative to IAEA they focus on damage to waste treatment buildings far more than we have done here, and the waste building adjacent to reactor 2 is damaged, providing a possible pathway, especially as they think its possible that hydrogen leaked into these building.

 

[SteveElbows]

While it would be hard to imagine a...nd pointing the finger at the reactor itself.

 

[SteveElbows]

The argument made there by the cabinet secretary seems pitifully inadequate, and indeed has a form that makes it look like a 'post hoc ergo propter hoc' fallacy. Very _much_ had been going on before those high levels were measured on the 15th and the 16th of March, and during this period smoke and steam were reported billowing out from several sources within the plant, not only, and not even mainly, from unit 2.

There must be more than guessing and imagining that they picked this scenario for sound reasons.Taking things from this particular report on trust alone is for me quite out of bounds.

I think its a combination of the theory of what happened at reactor 2, combined with the highest site radiation readings, SPEEDI data showing where it may travel matching pretty well with actual contamination, and perhaps some other factors that I haven't worked out yet.

Certainly there are a few complications, because up until the 15th they did not speak of containment failure, yet we know that reactor 1 had managed to spread some contamination away from the plant by the morning of the 12th, and as previously mentioned the SPEEDI data fro unit 1 explosion time also follows the north-west route. So one of the reasons I am interested in the report to IAEA pointing most of the blame at reactor 2, is that I cannot tell if they may have underestimated releases from reactor 1 and also 3, especially if they were sticking to their original narrative that unit 2 was the only one with containment damage. I cannot tell if they increased the estimates for reactors 1 & 3 after containment damage seemed likely there, for I do not have the original figures from April 12th in this much detail, only the later ones where total was upgraded past 800000 TBq.

 

[clancy688]

I cannot tell if they increased the estimates for reactors 1 & 3 after containment damage seemed likely there, for I do not have the original figures from April 12th in this much detail, only the later ones where total was upgraded past 800000 TBq.

Here you are: http://www.nisa.meti.go.jp/english/files/en20110412-4.pdf

 

[SteveElbows]

Here you are: http://www.nisa.meti.go.jp/english/files/en20110412-4.pdf

Thanks, but I was referring to figures which show the release per reactor. These are available for the latest version of the figures, table 5 on page 7 of attachment IV-2 in report to IAEA, but I've not seen an earlier version.

 

[MiceAndMen]

The panel that is missing from reactor 2 building is not by the fuel pool, rather it is close to the floor area above the reactor itself. There also remains some ambiguity as to whether this was blown off or removed deliberately. Official information states that it was removes as a result of explosion at 3, but that does not tell us with 100% clarity whether the explosion at 3 caused it to fall, or whether they removed it because of the explosion at 3, to prevent the same thing happening at 2.

There is a problem with all of those scenarios. The panel on the East side of Unit 2 was removed (or blown off) before Unit 3 exploded. There is indeed ambiguity in TEPCO's statements about exactly when and why that panel went missing.

http://www.flickr.com/photos/digitalglobe-imagery/5522088312/in/photostream/

(Thanks to MadderDoc for pointing that out to me some weeks back.)

 

[Azby]

Fukushima geology and groundwater

About the geology of the Fukushima area, I was able to consult a Japanese specialist, a professor of geology at a leading Japanese university, who provided lengthy and detailed explanations. Because he has been misquoted in the press recently he is reluctant to be identified publicly here, but has agreed to let me quote him anonymously. I've encouraged him to sign up and participate here, and maybe he will at some point. I asked him specifically about the solidity of the rock on which Fukushima Daiichi sits, and about the groundwater system in the area and implications for the spread of contamination by that route. His replies (excerpted, and even then it's pretty long):

"As for your question, there are limited number of info available, and the lack of info is more severe for English-language versions. Nuclear Plants are usually built on a stable rock, and granite is an ideal one: they are not only strong, but also deep-seated. I believe most of the nuclear plants in Japan are built on granite, and if it is not available, on other hard rock such as metamorphic rocks, but not for soft rocks such as sedimentary rock (or soft sediments) which would be suicidal*in terms of nuclear safety. Fukushima`s bed rock is a hard-rock complex called Abukuma Massif, and is made of granite and metamorphic rocks (= former sedimentary rocks which*was then*hardened by high pressure and temperature in the underground). So people thought the region is relatively safer in terms of bed rocks and fault systems. But after the 3-11 earthquake, many "inactive" fault systems moved, causing some problems such as landslides or forming sink holes. Some of these faults CUT through these hard rocks, which people, including many geologists, thought quite unusual (if not impossible) utill they saw the consequence of the 3-11 Earthquake in Tohoku. Even in the areas of hard bed-rocks, it might be covered by a veneer of soft sediments or soft rocks, and if the reactor is built in such areas, the degree of tremor due to earthquake will increase. Unfortunately in the case of Fukushima Daiichi Plant, there are thick sedimentary rocks of the Quaternary (Pliocene) age called*the Taga Group covers the Abukuma Massif (hard bed rock in depth here), and there are a few active faults around*the plant*(they have been recently*found to be active after the 3-11 Earthquake).*"

[snip]

"As for Fukushima`s geology, *yes, it has been long known that around the Fukushima Daiichi Plant is sedimentary rock Taga Group; around the plant this rock is called the Tomioka Formation, whch is made of coarse sandstone (or Grit) and tuffaceous siltstone. It`s pity that*no*geologists*(as*far as I know)*have warned the vulnebility of the Fukushima Daiichi Plant in terms of geology, as it won't take a rocket science (but so simple and clear) to check this out. But instead, I think most of us trusted info provided by Tepco, such as videos in*nuclear safety which states that "this region*of Fukushima Daiichi Plant have never experienced major earthquake or tsunami over the past 400 years". *
As for the groundwater-flow information, I don`t know. I checked several website, but I could not find one, including the one in Japanese. As the bedrock of the area is made of coarse sandstone, the rock is highly permeable and has plenty of waters flowing in the underground of the plain (but in a very very*slow speed) around the*nuke plant. The source (catchment of rain) is the nearby Abukuma mountains, and the groundwater of this nature will spend hundred or more years to flow from the mountains to the coastline. But I do not have data to prove this - I am just stating a general rule."

[snip]

"I have talked with some of my colleagues (geology professors) today, and some of them knew for many years/decades that the bed rock of the Fukushima Daiichi Nuke Power Plant is soft sedimentary rock. They do not know why government (both national and local/prefectural) approved for the construction of the plant on such a bad spot, and can only think of*unethical acts of polititians and the industry.*Also,*my colleagues warn that the type of bed rock, which geologists identify,*and the strength/suitability of the*bed rock, which soil/geo-engineers determine, is different, even though I would*still support that*young sedimentary rocks below the Fukushima Daiichi Nuke Plant is NOT*suitable for constructing buildings that have to endure earthquakes. "

[snip]

"One of my colleagues told me that ground water research have been usually done by local/prefectural municipal office(s), consulting firms, and AIST in Tsukuba, especially when the geothermal gradient of the region is high - as it might be leading to the discovery and development of onsen and other hot spa resort. Unfortunately Fukushima does not have such areas along the coast (but inlands such as Aizu), so he doubt that detailed measurements of groundwater have been done by these organizations (but those associated with the nuclear industry), and even if they do have such info, they might have not made it publically available (but you could try to inquire about the info to these organizations using the contact info I provided in the earlier e-mail). Just for my curiosity, I have checked the report map on the geology (or Hazard map) *of Fukushima Daiichi nuclear plant. It is in Japanese. It states/shows that the plant is away from active volcanoes and active faults (closest ones are about 8-9 km away) and supporting its safety against natural disasters. BUT THE MAP DOES NOT SHOW OR MENTION ANYTHING ABOUT THE BED-ROCK GEOLOGY OR GROUND WATER. The following is the link to this "Hazard map" issued by NUMO(Nuclear Waste Management Organization of Japan):
*
http://www.numo.or.jp/koubo/bunken_chisitsu/condition/07fukushima/07546.pdf[snip]

"This is all I could answer with my knowledge (and inputs from my colleagues). I think you may be able to get info of bedrock geology and groundwater (hydrology) by contacting

(1) GSI Japan
*http://www.gsi.go.jp/ENGLISH/index.html
*
(2) Fukushima Prefecture Construction Dept
http://wwwcms.pref.fukushima.jp/pcp...ECT&NEXT_DISPLAY_ID=U000004&CONTENTS_ID=11045

(3) AIST (advanced institute of science and technology, Japan, in Tsukuba)
http://www.aist.go.jp/index_en.html

(4) other agencies/institutions re: nuclear energy and disposable sites. But I doubt that they make the info open-access.

[end quote]
*

 

[clancy688]

Thanks, but I was referring to figures which show the release per reactor. These are available for the latest version of the figures, table 5 on page 7 of attachment IV-2 in report to IAEA, but I've not seen an earlier version.

Wow, I didn't know that. Nearly all of the stuff (90%) came from Unit 2.

 

[zapperzero]

About the geology of the Fukushima area, I was able to consult a Japanese specialist, a professor of geology at a leading Japanese university:

"Just for my curiosity, I have checked the report map on the geology (or Hazard map) *of Fukushima Daiichi nuclear plant. It is in Japanese. It states/shows that the plant is away from active volcanoes and active faults (closest ones are about 8-9 km away) and supporting its safety against natural disasters. BUT THE MAP DOES NOT SHOW OR MENTION ANYTHING ABOUT THE BED-ROCK GEOLOGY OR GROUND WATER.
*

Would you please be so kind as to point this professor to the Cryptome website? More specifically, to

http://cryptome.org/0004/daiichi-build-01.pdf and
http://cryptome.org/0004/daiichi-build-02.pdf

which appear to contain some site geology data?

 

[Azby]

Would you please be so kind as to point this professor to the Cryptome website? More specifically, to

http://cryptome.org/0004/daiichi-build-01.pdf and
http://cryptome.org/0004/daiichi-build-02.pdf

which appear to contain some site geology data?

I did, and his reply was:

"I had a quick look at the report, and the geology (bed rock) is the grit (coarse sandstone) and siltstone, which is identical to the one I reported to you in my previous e-mail."

 

[Jim Lagerfeld]

Reactor 3 explosion does not generate interesting SPEEDI data at all, because the wind is mostly taking stuff out to sea on this date.

As a resident of Tokyo, I find the SPEEDI stuff from the 15th all too interesting! I remember reading in the Tokyo Shimbun at the start of April that the 'unexpectedly high' radiation recorded in Tokyo was due to the fact that the reactor three plume which 'went out to sea' actually looped back and licked Tokyo and Chiba.

When the SPEEDI maps finally came out, this made some sense. Compare the shapes on these predictions:

http://www.mext.go.jp/component/a_menu/other/detail/__icsFiles/afieldfile/2011/05/10/1305748_0315_06.pdf

To this contamination map by Yukio Hayakawa @ Gunma University:

http://maps.google.co.jp/maps/ms?ie...2043,140.097656&spn=3.203668,4.257202&t=p&z=8

In my opinion no one has officially explained nor factored in the full significance of the contaminated green tea from Shizuoka (150km south west of Tokyo) yet, however those SPEEDI plumes just kiss Shizuoka too.

I'm also guessing the makeup of the reactor 3 plume should be significantly different from the reactor 2 plume due to the completely different release path - they should be able to 'fingerprint' them, right?

 

[tsutsuji]

But second you need more than a tsunami to kill a NPP. It's often overseen, but Fukushima Daiichi didn't lose cooling capability because of the tsunami. The station blackout happened because offsite power was lost due to collapsing electricity lines which were damaged by the earthquake.
If those towers would've withstood the earthquake, perhaps emergency cooling could've been sustained.

To the difference with the nuclear systems which require to wait years until a camera can enter the reactor and tell us what happened, we don't need to wait that much to learn the lessons from this accident concerning the power transmission systems :

For example, sufficient consideration was not given to the following actions required for improving reliability of off-site power supply and auxiliary power system.
* Assessment to assure reliability of supplying power to nuclear power stations if a main substation stops supply
* Measures to improve reliability by connecting external power transmission lines to units at the site
* Seismic measures for external power lines (power transmission lines)
* Tsunami countermeasures for power receiving equipment in switching stations

IV-130 http://www.kantei.go.jp/foreign/kan/topics/201106/pdf/chapter_iv_all.pdf

I am a bit disappointed that the specific "lessons learnt" chapter (chapter XII) fails from restating the above, insisting mostly on "failures derived from a common cause " and "preparing various emergency power supply sources" under "(2) Ensure power supplies" page XII-3 http://www.kantei.go.jp/foreign/kan/topics/201106/pdf/chapter_xii.pdf ). Is it because "Seismic measures for external power lines (power transmission lines)" is too expensive ? Is it feasible ?

 

[Borek]

About the geology of the Fukushima area, I was able to consult a Japanese specialist, a professor of geology at a leading Japanese university, who provided lengthy and detailed explanations. Because he has been misquoted in the press recently he is reluctant to be identified publicly here, but has agreed to let me quote him anonymously. I've encouraged him to sign up and participate here, and maybe he will at some point.

Thank you for your efforts - and send our "thank you" to the anonymous professor for his willingness to help

 

[yakiniku]

RE: Data released by the CTBTO as mentioned Posts 6087 and 6089, it has been mentioned that the ratios of xenon isotopes were unusual:

Were ratios of xenon isotopes unusual because reactor physics are poorly understood, or because of equipment being miscalibrated?

http://www.nature.com/news/2011/110613/full/news.2011.366.html

 

[MadderDoc]

<..>
The panel that is missing from reactor 2 building is not by the fuel pool, rather it is close to the floor area above the reactor itself. There also remains some ambiguity as to whether this was blown off or removed deliberately. Official information states that it was removes as a result of explosion at 3, but that does not tell us with 100% clarity whether the explosion at 3 caused it to fall, or whether they removed it because of the explosion at 3, to prevent the same thing happening at 2.

I am not sure which official information you are referring to. As you describe it, this information seems to say unambiguously that the panel was in place in the south wall of unit 2 until the explosion of unit 3 on March 14th -- leaving it only ambiguous whether the panel fell off due to that explosion, or whether it was actively removed, prompted by its occurrence. However, photographic evidence shows conclusively that the panel was not in place already by the morning of March 13th.

As for pathway of release, I am not sure. In the narrative to IAEA they focus on damage to waste treatment buildings far more than we have done here, and the waste building adjacent to reactor 2 is damaged, providing a possible pathway, especially as they think its possible that hydrogen leaked into these building.

Indeed, quoting the report to the IAEA (my boldfacing):
"At around 6:00 on March 15, the sound of an impact was heard which was considered to have resulted from a hydrogen explosion. No visible damage was observed at the reactor building, but it was confirmed that the roof of the waste processing building which is neighboring to the reactor building was damaged. During these processes, radioactive material to be released into the environment, and as a result, the radiation dosage around the premises increased."

However, the photographic evidence supports _no progression_ of damage to the unit 2 neighbouring radiation waste building in connection with the explosion on March 15th in the unit 2 reactor building:
the roof of the unit 2 radiation waste building appears to have been damaged already in connection with the unit 1 explosion on March the 12th, and it does not appear to have suffered any further significant damage by later events.

 

[zapperzero]

"I had a quick look at the report, and the geology (bed rock) is the grit (coarse sandstone) and siltstone, which is identical to the one I reported to you in my previous e-mail."

Thanks a bunch.

 

[zapperzero]

RE: Data released by the CTBTO as mentioned Posts 6087 and 6089, it has been mentioned that the ratios of xenon isotopes were unusual:

Were ratios of xenon isotopes unusual because reactor physics are poorly understood, or because of equipment being miscalibrated?

http://www.nature.com/news/2011/110613/full/news.2011.366.html

Very interesting. They say they have detected niobium-95.

Also, rubidium-103 (which is rather odd as I think its half-life is measured in fractions of a second, maybe an error and they meant Ruthenium-103 which has a half-life of 39 days?).

 

[SteveElbows]

Wow, I didn't know that. Nearly all of the stuff (90%) came from Unit 2.

Yes, this is the reason why I have started going on about reactor 2 again in recent days. Before I saw that attachment, there was already some other place in the main report where percentage release of certain core substances was in a much wider range for reactor 2 than the other reactors, 1-6% instead of around 1% for other reactors. This got me interested, and then when I saw the table I just had to talk about it more.

As well as being interested in the reasons why reactor 2 is attributed so much of the contamination blame, I also have to consider the possibility that they could be underestimating releases from other reactors, either because at various stages they did not want to accept that there was any containment damage at the other reactors, or because of weather conditions.

 

[SteveElbows]

As a resident of Tokyo, I find the SPEEDI stuff from the 15th all too interesting! I remember reading in the Tokyo Shimbun at the start of April that the 'unexpectedly high' radiation recorded in Tokyo was due to the fact that the reactor three plume which 'went out to sea' actually looped back and licked Tokyo and Chiba.

If its ok with you I will discuss the detail of this on the other thread about wider contamination, as its a better fit and March 15th plumes have been mentioned there recently.

But for now I will just say that I think a multitude of weather & reactor event timing factors make it hard to be completely sure.