Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[PietKuip]

from Kyodo:

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant's No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level

I now looked at the logs on http://www.tepco.co.jp/en/nu/monitoring/

In the recent logs I can only find entries that the neutron signal is "under 0.01 μSv/h".

In the March 13 logs, it says mostly "under 0.001μSv/h" at the main gate, but sometimes "under 0.002".

Tepco has a weird way of communicating their data.

PS: http://www.tepco.co.jp/en/nu/monitoring/11031401a.pdf gives some readings as "under 0μSv/h". Idiots.

 

[83729780]

Today is the 11th day since sea water injection started and let's assume another two days
till pumps start working

--> 13 x 24hours x 2m3/hour x 34kg = 21216 kg salt

another estimate:

Richard T. Lahey Jr., who was General Electric’s chief of safety research for boiling-water reactors when the company installed them at the Fukushima Daiichi plant, said that as seawater was pumped into the reactors and boiled away, it left more and more salt behind. He estimates that 57,000 pounds of salt have accumulated in Reactor No. 1 and 99,000 pounds apiece in Reactors No. 2 and 3, which are larger.

http://www.nytimes.com/2011/03/24/world/asia/24nuclear.html?_r=1&hp
press date 24/03

 

[jlduh]

The TEPCO document on tsunamis that i posted confirm that the plant itself is built on a platform which is 10 to 13 meters higher than sea level. So in case of a wave whose height is around 14 meters, only the very top of the tsunami (which is not -relatively- a very big amount of water: 1 to 4 meters ) have entered the buildings location. This was enough unfortunately to damage the diesel generators which are in the first line (close to the sea). But it's not a so big amount for the buildings because most of the energy of the wave has been dissipated hitting the 10 to 13 meters height of the platform.

To come back on the subject of the neutron beams (up to 1,5 kms long) that tepco reported, can somebody tell me how this phenomenon was detected? Is it something you can see visually or was it through detectors?

thanks.

 

[jensjakob]

another estimate:



http://www.nytimes.com/2011/03/24/world/asia/24nuclear.html?_r=1&hp
press date 24/03

And - scary to read that cooling pumps at #5 has stopped...

 

[Arcer]

Not necessarily. At the coast - where the plant is located - water is clean, it collects debris as it flows over the land. Debris can be also left when water goes back to the sea, but there is an elevated land behind the NPP - so there was no water getting back through the plant area.

Thanks for your response.

There's plenty of damage shown as the tsunami flowed over the constructions and surfaces (extending over about 100 metes) to the east of the long turbine generator buildings back to the breakwater/harbour/coast - that's evident from the satellite images. Maybe that debris is partly piled up against the east face of those turbine buildings. Maybe some of it went out with the tsunami.

Even so I would have expected a 10 - 14 metre tsunami to take a lot of the debris around the north and south ends of the turbine buildings and between those buildings and some of it to be deposited to the west and also deposited to the west as it went back out. If it was 10 to 14 metres high I would have expected far more damage to the low level buildings to the west of the turbine buildings and there's little or none although there seemed to be some cars moved around from the satellite images.

As far as I'm aware the entire plant area is pretty flat and the only elevated land is about 100 metres to the west of the turbine buildings and that is about 60 metres to the west of the reactor buildings - the embankments for that elevated land are evident from the satellite images and are shown on the image below.

Those embankments would act as a barrier to further inland flow of the tsunami but wouldn't have stopped the tsunami getting back out through the plant area.

http://ekstrabladet.dk/template/v3-0/direct/article/picProxy.jsp?url=http://multimedia.ekstrabladet.dk/archive/00647/Japan_Earthquake_647291o.jpg&iw=925&ih=646&secid=1250&cbw=1210&cbh=818

On that image (or any other Fukushima image for that matter) where's the staining from a 10 - 14 metre high tsunami on the walls that even clean water would show just carrying a bit of surface debris and dirt just from the roads. It's just a bit puzzling that apart from it totalling the entire power plant operation so far the images show relatively little sign of such a huge tsunami at least to the west of the site.

edit: jlduh's response above clarifies that there's a change in level on the site near the line of turbine buildings.

 

[PietKuip]

To come back on the subject of the neutron beams (up to 1,5 kms long) that tepco reported, can somebody tell me how this phenomenon was detected? Is it something you can see visually or was it through detectors?

There are no neutrons as far as I can see. The word "beam" seems to be an error of translation - "ray" would be better.

The plant has a neutron monitor at the gate, and they are just reporting readings around zero. (Yes, even sometimes below zero.)

 

[Arcer]

More images from the work @ Fukushima:
http://www.b.dk/billedeserier/her-arbejder-de-mod-tiden-paa-fukushima

@Arcer: Take a look at some of the early pictures, you will see cars, containers and other large items swept as debris against the earth-berm. QUite powerfull it must have been

Thanks for your response.

Yes I've seen them. jlduh has clarified the lack of damage as apparently there'a large step in the site (not evident on the images I've seen published so far) somewhere near the turbine buildings that reduced the affect of the tsunami as that would mean it was much shallower as it progressed towards the west of the site.

 

[jlduh]

I want to report here that the french IRSN made a significant move this Wednesday in their daily report concerning reactor 3. The previous days they were still considering that the confinement could be ok on this one, but they changed their mind in the last two days. You can see the reports on this page: http://www.irsn.fr/FR/Actualites_presse/Actualites/Pages/201103_situation_au_japon.aspx#1

Translation for the forum:

21st of March: "The steam produced in the reactor vessel at the fuel contact is transferred to the confinement vessel that seems to be still intact.

22 nd of MArch: "The steam produced in the reactor vessel at the fuel contact is transferred to the confinement vessel that seems to be still intact (to be confirmed taking into account the steam plumes and the variations of pressures in this vessel)"

23 rd of March: ""The steam produced in the reactor vessel at the fuel contact is transferred to the confinement vessel that seems to be leaking based on pressure readings; this lack of integrity would be the origin of the continuous radioactive leakage in the environment (non filtered and not controled). A slight rise of the water temp in the reactor has also been observed"

I personnally feel since i saw the explosion on TV that this N°3 reactor got an explosion (in fact 3 almost simultaneous) very different than the first one, much more "deeper" with this specific black plume of dust and big debris rising vertically... This looked much more serious than the other one.

I repost here an image that i found (i think) on this thread, which shows it seems an original map in japanese with measured radioactivities around the reactors:

http://www.monsterup.com/upload/1300925395929.jpg

Obviously reactor 3 seems to concentrate much higher levels of radioactivity...

 

[Arcer]

The TEPCO document on tsunamis that i posted confirm that the plant itself is built on a platform which is 10 to 13 meters higher than sea level. So in case of a wave whose height is around 14 meters, only the very top of the tsunami (which is not -relatively- a very big amount of water: 1 to 4 meters ) have entered the buildings location. This was enough unfortunately to damage the diesel generators which are in the first line (close to the sea). But it's not a so big amount for the buildings because most of the energy of the wave has been dissipated hitting the 10 to 13 meters height of the platform.

To come back on the subject of the neutron beams (up to 1,5 kms long) that tepco reported, can somebody tell me how this phenomenon was detected? Is it something you can see visually or was it through detectors?

thanks.

Thanks for your response.

The plant being built on a platform helps to explain the puzzle and I assume that must apply to all the buildings/plant to the west of the turbine buildings area.

Many thanks.

 

[jlduh]

I extracted a "print screen" of the page of interest of the Tepco document with their screwed calculations and conclusions of max wave at 5,7m and a schematic representation of the plant on the platform. T/B is for turbine building, R/B for reactor building. S/B is... i don't know! Safety Buildings (generators)? This will clarify the configuration of the global layout i think.

http://www.monsterup.com/upload/1300925990704.jpg

 

[AntonL]

10 cubic meters of salt would mean about 0.4 m of sediment layer if it were to settle (which it will not).
As long as it is sloshy it can be moved by water pressure which is good.

If the main inlet to the PV is free of compact salt crystals (my guess is it will be) then they
can pump in fresh water and steadily dissolve the salt by pumping in more water. No idea what
they will do with the discharged water - they can't recirculate it and it is bound to be contaminated, heavily at first.

it is returned to the ocean

If that is the case than the discarded sea water would carry away much of the
concentrated NaCl from reactors which should make subsequent pumping less prone to failure.

No ways will water from within the reactor with damaged reactor core, be discharged into the sea!

 

[83729780]

No ways will water from within the reactor with damaged reactor core, be discharged into the sea!

several news sources give such an account; this the NY Times:

The Japanese have reported that some of the seawater used for cooling has returned to the ocean, suggesting that some of the salt may have flowed out again rather than remaining in the reactors.

we have to account for over [STRIKE]a cubic kilometer[/STRIKE] 1000 cubic meters of water

 

[Reno Deano]

Yes they would discharge seawater used to cool the reactor back to the sea or somewhere (sea better choice). They cannot allow the reactor vessel to go solid with liquids, especially with the continued heating from the degraded core.

They must have a crude recirculation path either to the Dry Well (blanketing the exterior of the reactor vessel with cooling liquid) or via the Feed Water path to inside the reactor vessel and the core.

 

[AntonL]

we have to account for over 1000 cubic meters of water

boiled away in the reactor and condensed somewhere else, presumably mostly in the torus and vented to the atmosphere.

 

[AntonL]

Yes they would discharge seawater used to cool the reactor back to the sea or somewhere (sea better choice). They cannot allow the reactor vessel to go solid with liquids, especially with the continued heating from the degraded core.

They must have a crude recirculation path either to the Dry Well (blanketing the exterior of the reactor vessel with cooling liquid) or via the Feed Water path to inside the reactor vessel and the core.

wishful thinking,

[/PLAIN]
Richard T. Lahey Jr., who was General Electric’s chief of safety research for boiling-water reactors when the company installed them at the Fukushima Daiichi plant, said that as seawater was pumped into the reactors and boiled away, it left more and more salt behind. He estimates that 57,000 pounds of salt have accumulated in Reactor No. 1 and 99,000 pounds apiece in Reactors No. 2 and 3, which are larger.

and presumably he knows what he is talking about and the capabilities of BWR

You could also study http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf".

 

[jarvik]

163.000 becquerels in soil northwest of Fukushima NPP:
http://www3.nhk.or.jp/daily/english/23_28.html

That is quite bad.?

Looking at the story it gives 163 000 becquerels/kg soil, which from the article I think they took from the top 5cm of the soil profile. The story also gives that 100 becquerels/kg is the upper limit of normal. Normal would be normal left over from 1960s global bomb test fallout I presume, (this would check out with my own experience of surface sediment typcally ranging from 1-200 becquerels 137 Cs/kg sediment).

Other naturally occurring radioisotopes 40K, 238U, 232Th and associated daughter products combined would probably add up to a 1000-10000 becquerels/kg soil I think (this can be considerably higher in some soils/regions) But even in the context of the total surface sediment activity it would appear the added 137Cs activity (I'm assuming it's recent reactor sourced fallout) is raising total soil activity by about 10-100 times..wow.

Makes me wonder about the 90Sr, 134Cs, 131I and other fission products in the soil too

Soil certainly isn't the only source of radiation to us humans but when I think about the other fallout nuclei that likely are also be present in large amounts in this soil such as 90Sr I'd be concerned. I don't know enough about human exposure issues to judge whether it crosses the line from meh to an increased longterm health risk for local residents though.

Anyone have a better take?

 

[AntonL]

http://www.jaif.or.jp/english/news_images/pdf/ENGNEWS01_1300936513P.pdf[/PLAIN] ]
Steam like substance rose from all unit-1, 2, 3 and 4 were observed from NHK’s helicopter.
This is the first time that steam like substance rose from Unit-1. (09:30, March 24)

does not look good

 

[AntonL]

Thanks for your comments and translation, jlduh. Interesting Are there any more specific details in the report that might be pertinent?

EDIT: My comments below have been proven wrong by TCups

We are comparing apples with pears!

The radiation map (the pink one) is from Fukushima Daini NPS
Although I cannot read Japanese I can read the numbers on the reactors
which compares with the Daini plant

also http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daini_march12_2011_dg.jpg" confirms this look at the arrangement of access roads.

 

[TCups]

Anton, RenoDeno:

Can you comment why the accumulation of NaCl from evaporated sea water poses such a concern and be more specific about where exactly that accumulation is likely to take place?

Will the irradiated NaCl be highly radioactive and highly soluble in water?

Does anyone know where are the off-shore currents likely to disperse the radioactivity initially?

 

[TCups]

We are comparing apples with pears!

The radiation map (the pink one) is from Fukushima Daini NPS
Although I cannot read Japanese I can read the numbers on the reactors
which compares with the Daini plant

Are you indeed sure?! Look again at the "pink" map. The blocks, I think, indicate the ground space rather than the buildings. I see reactors 1 - 4 lined up in back of the steam turbine bldgs and match the outlying buildings and even the tower to the satellite photo of Daiachi, not Daini. Am I wrong? I must look again, but I don't think so.

 

[AntonL]

Anton, RenoDeno:

Can you comment why the accumulation of NaCl from evaporated sea water poses such a
concern and be more specific about where exactly that accumulation is likely to take place?

because the salt crystals will clog the system and encase the fuel rods thus decreasing cooling
capacity, and grind away the impellers of http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf" and making these inoperative.

 

[AntonL]

Are you indeed sure?!

Hello TCups
Yes - I edited original post with below sentance

also http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daini_march12_2011_dg.jpg" confirms this look at the arrangement of access roads.

 

[TCups]

TCups - hat off - you are right!

Also Daini reactor are all inline

Now go back and match the radiation readings to the debris fields we spent so much time on earlier. . .

I must get some sleep.

 

[M. Bachmeier]

Now go back and match the radiation readings to the debris fields we spent so much time on earlier. . .

I must get some sleep.

So should I but you guys are so loud your keeping me awake.

 

[tortamuss]

Surface winds are due to temporarily turn onshore from the northeast @ the 25th

 

[jensjakob]

http://www.cnn.com/2011/WORLD/asiapcf/03/24/japan.nuclear.reactors/index.html?hpt=C1

Nishiyama:
"The "vapor" rising near the No. 1 reactor at the plant is "only natural" and not a cause for alarm, he said, especially since water is now in that unit's nuclear spent fuel pool"

-------
My comment: hmmmm, at least they are now telling us that #1 SFP is SERIOUS hot too... Has it been dry?
If I read the comment squarely, I could argue that he implies that before todays dousing, the pool was dry...

 

[jensjakob]

2 nuclear plant workers sent to hospital
Japan's nuclear safety agency says 2 workers at the Fukushima Daiichi nuclear power plant were taken to hospital on Thursday after being exposed to high-level radiation at the plant.

The agency says the workers' feet were accidentally exposed to 170 to 180 millisieverts of radiation while they were working in the turbine building of the Number 3 reactor.

A third worker was also exposed to radiation but apparently did not require treatment.
Thursday, March 24, 2011 15:43 +0900 (JST)
http://www3.nhk.or.jp/daily/english/24_39.html

 

[AntonL]

The austrian news http://www.orf.at/stories/2049349/2049348/"

Die Arbeiten I am Atomkraftwerk Fukushima I gehen nur langsam voran: Immer wieder müssen Arbeiter abgezogen werden, weil die radioaktive Strahlung zu hoch wird. „Nach gegenwärtiger Lage dürfen wir nicht zu optimistisch sein“, sagte Regierungssprecher Yukio Edano am Donnerstag auf einer Pressekonferenz in Tokio. Ausgerechnet die Kühlung, die langsam Wirkung zeigt, könnte zum neuen Problem werden.

Translated means:
The work at the nuclear power plant Fukushima I going slowly: Time and again, workers must be withdrawn because the radiation is too high. "According to current situation we must not be too optimistic, " said government spokesman Yukio Edano on Thursday at a press conference in Tokyo. Of all the cooling, showing slow action might become a new problem.

Is he referring to salt problem addressed earlier - and what does "we must not be too optimistic" mean?

 

[TCups]

2 nuclear plant workers sent to hospital
Japan's nuclear safety agency says 2 workers at the Fukushima Daiichi nuclear power plant were taken to hospital on Thursday after being exposed to high-level radiation at the plant.

The agency says the workers' feet were accidentally exposed to 170 to 180 millisieverts of radiation while they were working in the turbine building of the Number 3 reactor.

A third worker was also exposed to radiation but apparently did not require treatment.
Thursday, March 24, 2011 15:43 +0900 (JST)
http://www3.nhk.or.jp/daily/english/24_39.html

Jens - that would be the building in front of Unit 3 with the holes in the roof (and with radioactive debris now on its floor?).

http://s306.photobucket.com/albums/.../?action=view&current=Picture2-3.png&newest=1

 

[M. Bachmeier]

Jens - that would be the building in front of Unit 3 with the holes in the roof (and with radioactive debris now on its floor?).

http://s306.photobucket.com/albums/.../?action=view&current=Picture2-3.png&newest=1

NHK reported the workers were in the basement of #3, whatever that means.

 

[|Fred]

Lots of information was release regarding the situation at the plant this morning (GMT)
I'll try to get a proper translation...

The Underground of the turbine room linked to the unit 3 was flooded with 30 cm watter , the worker doing stuff there related to pump had there feet in the watter "radioactive" those were the worker rushed to the hospital (radiation exposure about 180 mSv)

edited

 

[jensjakob]

Ok, found this quote on BBC:
""Although they wore protective clothing, the contaminated water seeped in and their legs were exposed to radiation," said a spokesman."
http://www.bbc.co.uk/news/world-asia-pacific-12845304

 

[M. Bachmeier]

How can ANYONE go into a building with water in the basement below a reactor and SFP being cooled by dousing - and not think "WOW - bad idea, bad idea"?

Where are the disaster-management in this NPP?

I could accept it if they were working in the basement (high risk), and a pipe rupture - that would be an accident - but if the water was there allready - then I read this setup as a quite bad example of disaster management...

An idea that might even be worse is waiting too long to get the situation under control. I have a feeling the workers were aware that they were taking risks, but were weighing the consequences of further delays. There have been a lot of delays. Delays at this point are not good.

P.S. An NHK spokesman even implied the workers might not be wearing the safety equipment properly, but I doubt that.

 

[jlduh]

Well, my personal FEELING is that there is what is being said which (tries to) give the impression that some things are under control, like the personnel management concerning radiations. I'm not so confident with this, but only time will tell the true story and the reality behind this. There are always the words and the numbers on one side, and on the other side there is the "real thing". My work as an environmental expert for court and environmental management teached me that sometimes the two ones fit together. Sometimes.

We live more and more in a world of words, numbers and images, but reality still continue to exist and PREVAIL. With time, the two tend to better fit though. We are all here trying to fit words, numbers and images on a reality which we are not experiencing on the ground (fortunately for us) and this is always a tricky game (especially when these words, numbers and images are not from us but from other people!), we have to recognize the limit of this, even if obvioulsy we still can get a feeling of what's going on.

This moment, like every disaster, is a big come back to reality in a world where virtuality or "augmented reality" (hummmm!) seemed to replace the true experience of reality.

By the way, but i won't go further with this here, the guy talking in the CNN interview has a point of view which is typical of this tendency, as his conclusions is basically that the japanese would rather build psychiatric hospital than a sarcophagus to deal with the health consequences of the accident (to summarize it in a few words!). This is a strange way of dealing with reality. Military troops are always subject to psychic trauma of course but I'm not sure this trauma would be the same if they were fighting moving pixels with electronic weapons actioned by a keyboard/joypad in front of a 30 inch flat screen... This is a strange way of trying to describe the reality, yes.

 

[jlduh]

Back to interpreting words and numbers and images, i would like to add this:

1) no doubt the radiation map (whatever the way it arrived on the net, but it "looks" original...) is from the DAIICHI plant. But this has been agreed later by ANtonL. I can GUESS from what's is written that measurement are in millisieverts/h and that the date would be the 20th of March at 17h30.

2) there are other things maybe of interest in the IRSN reports but i can't translate everything of course. One thing is that from the very beginning, they have always added a paragrah in bold letters saying that they are very (i sumarize in a few words) concerned by the risk of cristallization of salt in the reactors which could block various things and reduce the efficiency of the cooling process in the short term. They also urge the japanese to shift as quickly as possible to fresh water cooling (which is obvious!).

3) one thing is clear: a lot of things are not clear! If you read the various statements of various organisations or experts, you find huge contradictions amongst the number of them and over the time being. The situation of the pools is a good example. But this is understandable: autorities are saying things which they think are true, and they may also say things that they know are wrong... If you multiply this uncertainty by the numbers of organisms dealing with the accident in japan but also abroad, you get a idea of the floating world of words and number over the crude reality (back to my previous post). But with time again, the smoke is going to fade and the real picture is going to appear...