Japan Earthquake: Nuclear Plants at Fukushima Daiichi

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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.
  • #7,921
Astronuc said:
...

Fascinating stuff as ever. If [insert descriptive term] extract that kind of insight by way of refutation, maybe I should feel more tolerant of them.

I say that as a long term thread watcher who spends most of his time biting his lip, so as not to dilute the thread with yet more non-scientific opinion of which there is an excess, and increasingly so, to the point where I am questioning the worth of following the thread at all.

Your post reminds me of why I joined this forum in order to follow this thread.
 
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  • #7,922
Astronuc said:
Does one have a reference or citation? It is not possible to answer without knowing what kind of counting/survey was done. Possibly the person was scanned with a whole body counter. Normally one is scanned in and out of restricted (controlled access) areas at an NPP. The objective is to prevent radioactive substances from entering or leaving.

No real reference...it was just from the article posted above. I was just reading it thinking...how high was it 10 days earlier if these numbers are correct.
 
  • #7,923
Sabbatia said:
No real reference...it was just from the article posted above. I was just reading it thinking...how high was it 10 days earlier if these numbers are correct.
It may not reflect one isotope, but several.

In such cases, one would apply retrospective dosimetry - at least, I would hope so.

http://www.sckcen.be/en/Our-Research/Scientific-Institutes-Expert-Groups/Environment-Health-and-Safety/RP-Dosimetry-and-Calibration/Retrospective-dosimetry
 
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  • #7,924
"" The half life for iodine is like 8 days right? two days later he was down to 1500 and went back to work. 10 days is time for one halflife before he was tested...but somehow the math isn't working for me. Can someone explain this?? ""

well having worked in such a plant, those numbers aren't scary.

But no i can't explain it absolutely.
Could be as simple as two different individuals scanned the guy. After a "Technicium Stress Test" of my heart i was so radioactive that i set off the plant exit monitors from a hundred feet away . Of course i was not allowed around the radiation area - they wouldn't be able tell the internal radioactive medicine from contamination so i was not allowed around any contamination until the stuff went away. Took about three weeks.

The HP (Health Physics- radiation monitoring guy) who scanned me at first was very thorough, read close to my thyroid and other organs, hair, intestines, and wrote down several readings on a chart to get a feel for where my body was stashing the stuff. Afterward they were less thorough because they knew what i had was not from the plant.
The initial numbers were high enough they were in micro-r/hour not individual counts. When the counts are so high they run together to form a continuous stream you switch to dose rate not count rate - like a leaky faucet it can be individual drips per minute or a continuous stream measured in milliliters per minute.
So long as they were still reading individual counts on me i wouldn't worry.

So my guess is the two numbers might be highest one day and average another day, or maybe his body eliminated some of the stuff by biology - iodine pills would do that.

I hope he got some rest.

old jim
 
  • #7,925
The second group of 3 pictures on this TEPCO page is interesting. They might show the location of the "very high dose rate material that had to be bulldozed over between Units 3 and 4".

http://www.tepco.co.jp/tepconews/pressroom/110311/index-j.html

This one shows the area which looks to me like it is between units 3 and 4.
http://www.tepco.co.jp/en/news/110311/images/110521_3.jpg

This one shows a sign in front of a pile of rubble that reads in part "1000 mSv/h"
http://www.tepco.co.jp/en/news/110311/images/110521_1.jpg

And the third one is the same pile of rubble with some annotation in Japanese.
http://www.tepco.co.jp/en/news/110311/images/110521_2.jpg

There is some interesting green material in the area that looks to be broken metal of some sort. I don't think it's current location is much help in trying to determine where it came from since the bulldozing would have moved it from its original location on the ground after the explosions.

The barricade the sign is hanging from looks more like a velvet rope entrance to a fancy nightclub than it does a warning of dangerous conditions.

Edit: UPDATE: This story at NHK says they found 1000 mSv/h debris on Friday south of unit 3. That's probably what's shown in the pictures above. http://www3.nhk.or.jp/daily/english/22_07.html

The story also says it's the highest level of radiation they've found in the debris, which leaves the question open as to what they found in the first weeks that they bulldozed.
 
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  • #7,926
MiceAndMen said:
<..> I don't think it's current location is much help in trying to determine where it came from since the bulldozing would have moved it from its original location on the ground after the explosions.

It cannot be excluded that the object has been moved from even the other end of the plant and has been dropped here for some exciting and mystifying reason, but the simplest explanation does seem to be that it has been found rather close to where it fell.

The position of the pile itself and the marked location for the object in it, suggests to me that the object has probably not been moved by more than a few meters from its original location.

The pile itself appears to be the one formed, when access to sfp3 for the concrete pump was superficially cleared at some time between March 20th and March 24th. Since then the pile seems to have had only removed from it, e.g. the easily recognizable corrugated iron strips originating from the roof -- they may have been picked out to be moved to some other place for disposal -- however otherwise this pile does not appear to have perceptibly changed.

The barricade the sign is hanging from looks more like a velvet rope entrance to a fancy nightclub than it does a warning of dangerous conditions.

A very fine sign and barricade indeed.

Edit: UPDATE: This story at NHK says they found 1000 mSv/h debris on Friday south of unit 3. That's probably what's shown in the pictures above. http://www3.nhk.or.jp/daily/english/22_07.html

The story also says it's the highest level of radiation they've found in the debris, which leaves the question open as to what they found in the first weeks that they bulldozed.

It could be the same piece.
 
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  • #7,927
MiceAndMen said:
This one shows the area which looks to me like it is between units 3 and 4.
http://www.tepco.co.jp/en/news/110311/images/110521_3.jpg

Yes. There is a small evidence for slightly higher temperatures around this pile of rubble. But maybe just warm pipes:

34e22yh.jpg
 
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  • #7,928
NISA issued a long statement on May 16th about the transfer of contaminated water from unit 3 to the Radioactive Waste Treatment Facility's incinerator building :

The high-temperature incinerator building’s floors and walls possesses the necessary water-tightness according to leakage volume assessment.
(...)
every visually-identified crack was confirmed to have been repaired with polymer cement waterproof coating.
http://www.nisa.meti.go.jp/english/files/en20110520-2.pdf

Astronuc said:
Does one have a reference or citation?

Are you looking for http://mdn.mainichi.jp/mdnnews/news/20110521p2a00m0na021000c.html ? Or for Mainichi's sources ? I tried to look at NISA's latest press releases, but could not find anything related so far. There is a full video record of the House of Representative's Budget Committee meeting on May 16th at http://www.shugiintv.go.jp/jp/video_lib2.php?u_day=20110516
 
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  • #7,929
MadderDoc said:
It could be the same piece.
That had crossed my mind too. It was probably originally on the ground somewhere between units 3 and 4, so it wasn't moved a great distance. I was thinking more along the lines of whether it fell from the east or west side of the building (unit 3 seems most likely).
 
  • #7,930
Joe Neubarth said:
Somewhere in the 496 pages of this string there was a photo of a BWR in the shipyard/construction yard. It had the main components and was all metal with a single man who looked tiny on the structure. Can anybody repost that again? It was a great photo but I can not find it.

Perhaps

attachment.php?attachmentid=33800&d=1301592834.jpg
 
  • #7,931
MiceAndMen said:
Edit: UPDATE: This story at NHK says they found 1000 mSv/h debris on Friday south of unit 3. That's probably what's shown in the pictures above. http://www3.nhk.or.jp/daily/english/22_07.html

The story also says it's the highest level of radiation they've found in the debris, which leaves the question open as to what they found in the first weeks that they bulldozed.

I'm wondering what is the material in that picture that is the source of that much radiation, and how did it get from inside the reactor (or fuel pond) to that location. Is it just me, or does it seem like the explosions caused radioactive fuel to be ejected? If it's not fuel, what could it be?
 
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  • #7,932
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  • #7,933
here is image from tepco, with description where exactly radioactive part is: http://www.tepco.co.jp/en/news/110311/images/110521_7.jpg
 
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  • #7,934
elektrownik said:
here is image from tepco, with description where exactly radioactive part is: http://www.tepco.co.jp/en/news/110311/images/110521_7.jpg

But, seeing that the white circle as well as the splotch of red painted concrete to the left of it are both landmarks perhaps 5 meter across it is not exactly an X marks the spot situation :-)
unit3_1Svdebris.jpg
 
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  • #7,935
elektrownik said:
RCIC is powered by steam, so fluctuations in amount of steam = fluctuations in RCIC

I see you are online, you may have missed my request for the following info, as i did not see your post until much later... would appreciate it if you could answer the following...

Am interesteded in the original source of the info about RCIC powered by steam, and do you know the "supply source of the steam" to operate? thanks
 
  • #7,936
tsutsuji said:
Tepco releases a gamma ray photograph taken at the ground floor of unit 1 reactor building. It shows some parts of ventilation ducts suffer a high level of radiation :

http://www.hokkaido-np.co.jp/news/dogai/294071.html
http://www.tepco.co.jp/nu/fukushima-np/images/handouts_110522_01-j.pdf (bigger pictures)

The "gamma camera". It might look a bit Heath Robinson but I salute the ingenuity in it. It's the kind of engineeriing I think a lot of us were hoping to see some time ago.
GC.jpg


There are some new images of the Megafloat arriving here:
http://www.tepco.co.jp/en/news/110311/index-e.html"
 
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  • #7,937
MiceAndMen said:
This one shows a sign in front of a pile of rubble that reads in part "1000 mSv/h"
http://www.tepco.co.jp/en/news/110311/images/110521_1.jpg

I can't recognize anything on the picture... But it's still very interesting. There are several 'overexposed' spots across the picture - are those traces of radiation hitting the CCD chip?
 
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  • #7,938
maddog1964 said:
Am interesteded in the original source of the info about RCIC powered by steam, and do you know the "supply source of the steam" to operate? thanks

Reactor is source of steam, then steam is going to turbine, this turbin is connected to pump, water source is torus, pump is pumping water from torus to RPV and steam which go to turbine is condensated in torus.
http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash4/188425_211896475487877_113650851979107_876237_7212984_n.jpg
 
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  • #7,939
Rive said:
I can't recognize anything on the picture... But it's still very interesting. There are several 'overexposed' spots across the picture - are those traces of radiation hitting the CCD chip?


I wondered the same thing, you see it in a lot of pictures. and the underwater video of the SFP i just can't see some of the wildly zipping white spots as bubbles..


I never questioned it, just assumed since it hasn't been mentioned here that it wasn't anything abnormal.
 
  • #7,940
Rive said:
I can't recognize anything on the picture... But it's still very interesting. There are several 'overexposed' spots across the picture - are those traces of radiation hitting the CCD chip?

I don't think so, it can be some plastic radiation shield which make quality bad
 
  • #7,941
Rive said:
There are several 'overexposed' spots across the picture - are those traces of radiation hitting the CCD chip?

Lens in a simple camera is not able to collimate neither of the possible radiation types, if anything, whole image should be overexposed the same way.
 
  • #7,942
Borek said:
Lens in a simple camera is not able to collimate neither of the possible radiation types, if anything, whole image should be overexposed the same way.

The most of these pixel errors I saw near Unit 2 (please zoom into the darker areas). Good to hear, radiation can't be the reason:

http://img542.imageshack.us/img542/4963/no2fallout.th.jpg
 
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  • #7,943
elektrownik said:
Reactor is source of steam, then steam is going to turbine, this turbin is connected to pump, water source is torus, pump is pumping water from torus to RPV and steam which go to turbine is condensated in torus.
http://a2.sphotos.ak.fbcdn.net/hphotos-ak-ash4/188425_211896475487877_113650851979107_876237_7212984_n.jpg

Thank you, that's what I thought I had also seen, but also thought I saw conversation that someone was saying that the shutting of the main steam isolation valve deprived the system of steam to operate the turbine. According to your diagram the tap for the steam to the cooling system is before the main isolation vavle and would not effect the operation of the system. Being a simple diagram and not showing all vavles/and controls there still could be other things that would efffect the operation. Thanks, to many threads to find!
 
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  • #7,944
Borek said:
Lens in a simple camera is not able to collimate neither of the possible radiation types, if anything, whole image should be overexposed the same way.

So http://www.youtube.com/watch?v=jFNvYA7731o" is a wrong interpretation?

I mean (while I don't claim that this is correct because of the lack of knowledge) most of the images in "suspicious" places have those artifacts (i.e. inside the factory), while images looking elsewhere (i.e. distant, looking at the sea, outside, etc) don't. If true then those can also be burned pixels from previous shots and may not be the result of the current shot.
 
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  • #7,945
maddog1964 said:
I see you are online, you may have missed my request for the following info, as i did not see your post until much later... would appreciate it if you could answer the following...

Am interesteded in the original source of the info about RCIC powered by steam, and do you know the "supply source of the steam" to operate? thanks

I'm not who you asked but maybe this will help.


The RCIC is used on units 2,3, 4. Unit one has a a Core Isolation Condenser instead.

The RCIC is shown on many different diagrams of the plants but I don't have one handy. The steam source is the reactor. When the reactor is shut down, it is still hot and makes lots of steam. Prior to the steam isolation valve feeding the main turbine there is a tee that taps off steam for the RCIC turbine. As long as the reactor is hot enough to make enough steam, the RCIC is available. When the decay heat is decreased too far to make adequate steam then other cooling systems are ASSumed to be available. The RCIC pump can take water from the torus or the condensate tank as selected by the operator.
 
  • #7,946
v13 said:
So http://www.youtube.com/watch?v=jFNvYA7731o" is a wrong interpretation?

I mean (while I don't claim that this is correct because of the lack of knowledge) most of the images in "suspicious" places have those artifacts (i.e. inside the factory), while images looking elsewhere (i.e. distant, looking at the sea, outside, etc) don't. If true then those can also be burned pixels from previous shots and may not be the result of the current shot.

OK, there was a misunderstanding. You wrote about "overexposed spots" and I thought what you mean is that some objects on the picture look overexposed, while you meant something that I would describe as similar to "hot pixels". I can easily imagine these can be effect of radiation. It would be interesting to try to estimate level of radiation that could give effect similar to that seen on the picture - but it doesn't have to be high. I have no doubt about elevated level of radiation near or in buildings, but it is intensity that is important, not just the fact.
 
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  • #7,947
Borek said:
OK, there was a misunderstanding. You wrote about "overexposed spots" and I thought what you mean is that some objects on the picture look overexposed, while you meant something that I would describe as similar to "hot pixels". I can easily imagine these can be effect of radiation. It would be interesting to try to estimate level of radiation that could give effect similar to that seen on the picture - but it doesn't have to be high. I have no doubt about elevated level of radiation near or in buildings, but it is intensity that is important, not just the fact.

FWIW, I'm not the one that wrote the post you replied (i.e. the post about overexposure) :-)
 
  • #7,948
intric8 said:
Whoa, NISA comes clean about isotope ingestion resulting in considerable exposures to thousands who were involved early on at Dai-ichi.

http://mdn.mainichi.jp/mdnnews/news/20110521p2a00m0na021000c.html

Some dose calculations these poor guys got, or are expected to get:

http://www.falloutphilippines.blogspot.com/

I always suspected that they were understating potential exposures, but i still find this a bit unsettling. Information is constantly subject to change out of the Japanese agencies, and most often, for the worse.

While I cannot find the article anymore (I had saved the text because I found it very alarming and had questions about it), Kyodo had reported the following around the 21st of March, which now fits nicely into the picture:

“A radiation level of 100,000 counts per minute will be introduced as a new standard for decontamination, up from 6,000 counts per minute, the government said, adding that raising the bar will not endanger health. The government's Nuclear and Industrial Safety Agency said the decision was made based on advice from domestic nuclear experts and the International Atomic Energy Agency. As the number of people who want to undergo radiation checks has surged, a lack of staff and equipment for the tests and decontamination was feared.”

Gives the impression that NISA may have anticipated this already mid to late March or potentially even known about it happening.
 
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  • #7,949
robinson said:
I'm wondering what is the material in that picture that is the source of that much radiation, and how did it get from inside the reactor (or fuel pond) to that location. Is it just me, or does it seem like the explosions caused radioactive fuel to be ejected? If it's not fuel, what could it be?

I would suspect that there are a number of pieces of equipment from the service floor level that end up rather radioactive, but I have absolutely no idea what level of radiation readings we should expect from them.

Certainly this pile of rubble has long interested me, it was previous labelled as up to 300mSv on the site radiation map, I guess they got closer to part of it this time. Anyway one reason why this pile of rubble always interested me is because it would be one of a number of locations where we might figure the fuel handling mechanism may end up under certain conditions. Unfortunately the pictures we previously had of this rubble were in no way detailed enough to make any useful comments about this rubble, the only thing I could previously say about the rubble over a slightly wider part of this site is that some parts of wall and roof could be seen.

Now I don't think I should read too much into the small green parts that can be seen on these new photos, but I would be keen to know more about the object shown in the attached photo. I am trying to establish whether there is a chance that this could be the telescopic part of the fuel bridge, with the idea that the bridge, or part of it, may have landed upside-down in this area. Even if we cannot say that this object may fit the bill, can anybody comment on how radioactive we may expect this part to be?

I am pretty sure there are quite a number of other objects that this bit of debris could be, so I am not exactly convinced of this theory myself, just throwing it out there.
 

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  • #7,950
mscharisma said:
While I cannot find the article anymore (I had saved the text because I found it very alarming and had questions about it), Kyodo had reported the following around the 21st of March, which now fits nicely into the picture:

“A radiation level of 100,000 counts per minute will be introduced as a new standard for decontamination, up from 6,000 counts per minute, the government said, adding that raising the bar will not endanger health. The government's Nuclear and Industrial Safety Agency said the decision was made based on advice from domestic nuclear experts and the International Atomic Energy Agency. As the number of people who want to undergo radiation checks has surged, a lack of staff and equipment for the tests and decontamination was feared.”

Gives the impression that NISA may have anticipated this already mid to late March or potentially even known about it happening.

Greater levels of radioactive materials found due to rain
TOKYO, March 22, Kyodo
 

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