What happened at Fukushima Daiichi during the Japan earthquake?

[Astronuc]

The problem in the evacuation zone is two-fold: 1) exposure of anyone within the zone, and 2) the possibility of transporting radioactive particles outside of the zone when leaving. The government doesn't want uncontrolled or untraceable exposure, i.e., they don't want the problem growing bigger than it already has.

As for inside the zone, the safest place is actually in doors, since the deposition is on outside surfaces. The problem for someone wanting to stay inside the zone is that if they go in and out of a dwelling, they may carry radioactive material inside the dwelling.

As far as I know, the government allowed some flexibility in the evacuation zone, but now the exclusion is mandatory.

 

[rowmag]

I find there's a schematic floorplan of the service floor of unit 3 on page 28 in this pdf (see also attachment below, with the schematic tentatively x/y scaled):

http://www.pref.fukushima.jp/nuclear/info/pdf_files/100805-6.pdf​

https://www.physicsforums.com/attachment.php?attachmentid=34862&d=1303728878

Interesting notation on that image: "In order to keep foreign matter out of the stored MOX fuel, a plastic cover is placed over the top." Which makes me think of cphoenix's superheated water/steam explosion theory. If pumps stop, and there is a plastic lid over the assemblies, it sounds like his conditions could be satisfied:
https://www.physicsforums.com/showpost.php?p=3254513&postcount=4158

 

[NUCENG]

Interesting notation on that image: "In order to keep foreign matter out of the stored MOX fuel, a plastic cover is placed over the top." Which makes me think of cphoenix's superheated water/steam explosion theory. If pumps stop, and there is a plastic lid over the assemblies, it sounds like his conditions could be satisfied:
https://www.physicsforums.com/showpost.php?p=3254513&postcount=4158

What is there about MOX fuel that requires that kind of protection, that doesn't apply to UO₂ fuel?

 

[rowmag]

The problem in the evacuation zone is two-fold: 1) exposure of anyone within the zone, and 2) the possibility of transporting radioactive particles outside of the zone when leaving. The government doesn't want uncontrolled or untraceable exposure, i.e., they don't want the problem growing bigger than it already has.

Yes, Astronuc. That is exactly what I think was trying to be said.

 

[|Fred]

Looking at unit 4, pink plastic seems there standard procedure when refueling regardless of mox .. that said the pdf seems to be discussing a lot about Mox.

rowmag might find answers within

 

[rowmag]

Looking at unit 4, pink plastic seems there standard procedure when refueling regardless of mox .. that said the pdf seems to be discussing a lot about Mox.

rowmag might find answers within

The PDF file is specifically a report on the condition of the long-term stored MOX at Unit 3, but that doesn't exclude the possibility that plastic covering is standard procedure regardless of the fuel. Have so far just skimmed the file, though.

 

[PietKuip]

The problem in the evacuation zone is two-fold: 1) exposure of anyone within the zone, and 2) the possibility of transporting radioactive particles outside of the zone when leaving. The government doesn't want uncontrolled or untraceable exposure, i.e., they don't want the problem growing bigger than it already has.

The second problem is utterly negligible in comparison to all other problems (all the other stuff alread there, the continued emissions, the winds blowing dust out of the zone). It sounds like a legal pretext.

And it contributes to this notion in Japan that radioactive contamination is contagious or something. We even see reports of atrocious behaviour at health care institutions, that really should know better. And the interpreter seems to have had the same notion in her head.

Mandatory evacuation makes sense for families with children. But pensioners can be given a choice, after they have been made aware of the risks. It is like smoking cigarettes.

 

[Joe Neubarth]

Mandatory evacuation makes sense for families with children. But pensioners can be given a choice, after they have been made aware of the risks. It is like smoking cigarettes.

There should be no vacillation on the part of health authorities. Just because older people might not make good decisions, does not mean that Health Authorities can pass on their responsibilities.

 

[Joe Neubarth]

Hey, guys, I read a newspaper story about sea water samples that maintained that I-131 is INCREASING in the recent samples. Are there any current data that confirms this?

 

[Dmytry]

The word generally used is 放射能, radioactivity. No need for dysphemisms.

yes yes of course Russian also uses word 'radioactivity'.
How do they call contamination with radioactive materials? The English word 'contamination' is not very specific, can be used for something contagious. Russian word is specific, made dirty, never used for viruses or bacteria.

"The second problem is utterly negligible in comparison to all other problems (all the other stuff alread there, the continued emissions, the winds blowing dust out of the zone). It sounds like a legal pretext."
At least, if the fallout is what they tell it is. Which is not necessarily so. F/e there may be hot spots that are REALLY hot to the point of giving you skin rash.

"And it contributes to this notion in Japan that radioactive contamination is contagious or something. We even see reports of atrocious behaviour at health care institutions, that really should know better. And the interpreter seems to have had the same notion in her head."

Yep. It is easy to get this sort of notion. Radiation sickness, radiation radiates around, radioactivity, people mix up the radiation and radioactivity to start with, plus the reactor obviously somehow makes radioactivity. In public mind it is as if humans were made of something fissile with very big fraction of long-delayed neutrons.
The craziest thing is that public misunderstanding is often something more complicated than it really is.

What was really crazy also - what did they do about that problem? Govt did declare state of emergency, right? Could it have declared this to be treacherous or w/e, and promise some severe legal consequences for this denial of medical care?
I mean, seriously, imagine some really bad disaster happens, and some capitalist immediately buys all the necessities and starts selling them with huge mark-up. He'd go to jail, right? Or have his stuff seized.

 

[DSamsom]

This morning NHK reported problems in temperature of SFP unit 4.

http://www3.nhk.or.jp/daily/english/25_12.html

This might be an awkward dilemma for the oprerators since spraying water in large amounts was considered a risk for the damaged structure of the pool. Now spraying too little poses a risk of once again exposing the fuel rods directly to air.

Anyone heard more about this?

 

[elektrownik]

This morning NHK reported problems in temperature of SFP unit 4.

http://www3.nhk.or.jp/daily/english/25_12.html

This might be an awkward dilemma for the oprerators since spraying water in large amounts was considered a risk for the damaged structure of the pool. Now spraying too little poses a risk of once again exposing the fuel rods directly to air.

Anyone heard more about this?

There is something wrong with #4 sft, science many days there wasnt so big problem, they were injecting 60-70t per day and temperature was stable, now science few days temperature is very height (80,70,90C) from unknown reason, and now they are injecting 200t of water per day, this is danger becouse building structure could be damaged, #4 sft is very heavy becouse there is so much fuel, ther was many aftershocks, mayby one of theme increase leak from sfp, we don't know...

 

[clancy688]

Something very interesting I just discovered - apparently television images of the Unit 4 explosion / fire.
But it's hard to see anything...

 

[ascot317]

This morning NHK reported problems in temperature of SFP unit 4.

http://www3.nhk.or.jp/daily/english/25_12.html

This might be an awkward dilemma for the oprerators since spraying water in large amounts was considered a risk for the damaged structure of the pool. Now spraying too little poses a risk of once again exposing the fuel rods directly to air.

Anyone heard more about this?

I'll quote because NHK links are not very long lasting:
"Tokyo Electric Power Company, or TEPCO, says it will inject 210 tons of water into the pool on Monday, after finding on Sunday evening that the temperature in the pool had risen to 81 degrees Celsius.

The utility firm had earlier limited the amount of water being injected into the pool to 70 tons a day, saying the weight of the water could weaken the reactor building, which was already damaged in last month's hydrogen explosion.

On Friday, TEPCO found that the pool's temperature had reached 91 degrees, so it began injecting 2 to 3 times the amount of water.

TEPCO says the pool's water temperature dropped to 66 degrees on Saturday after water was injected, but started to rise again, to 81 degrees.

The operator says the water level in the pool was 2.5 meters lower than normal after 165 tons of water were injected on Sunday. It is carefully monitoring the water level and temperature to avoid further troubles."

They better get some pumping and cooling equipment there, preferably with a heat exchanger, to exchange water and cool it down.

Would be quite a sight to see SFP#4 breaking down.

Something very interesting I just discovered - apparently television images of the Unit 4 explosion / fire.
But it's hard to see anything...

where did you find these?

 

[clancy688]

where did you find these?

A recent german documentation about Chernobyl and Fukushima:

@9:50 -

 

[MadderDoc]

I think it is a door. If you look really closely at biffvernon's picture, you can see the outlines of it on the right-hand side of the area that looks like a hole in other pictures. When it is open, it swings out to cover the left (as seen from the outside), so the square "hole" seen in other pictures is the combination of the inside of the open door and the interior of the building seen through the open door frame. <..>

I do think I see what you are pointing to, but I cannot quite make the suggested arrangement with an open door fit the apparent pre-explosion hole in the east wall of unit 4

Here is a zoom of biffvernons picture with the approximate extent of the 'hole area' marked up, and sided by a zoom from the original photo of the 'hole'. The markup has been done by looking at the blue and white pattern of the wall deco.

 

[|Fred]

..

*Ponder*
[PLAIN]http://img850.imageshack.us/img850/2685/unit4preexplosionhole.jpg

 

[Danuta]

So the interpreter misinterpreted? My transcription of her translation of the problematic sentence:
"... individuals who would enter these areas because if they come out of these regions the radiation contamination of these individuals may affect other people outside of this area. Therefor such a decision had been made."

I suppose the people sitting there would have had sufficient passive knowledge of English to be able to correct her?

Fukushima Hibakusha? I can't believe it. But, you are right, the translator translated correctly. They've had how many years since Hiroshima and Nagasaki to dispel this kind of crap?

http://blogs.wsj.com/japanrealtime/2011/04/20/leaving-fukushima-radiation-check-please/"

 

[|Fred]

Discrimination is one strange way to look at it.. .
If some one has not a paper saying that he has been screened they do screen them.
Looking at this part I only see a safe way to be sure everyone is screened to be sure he is in no danger.. And I don't see how it is wrong ..

Discrimination against irradiated, is something that has nothing to do with this process...

 

[MadderDoc]

..
On April 22nd, the webcam showed steam coming from unit 4 from 16:00, intensifying by 17:00. From 17:52 to 23:53 (6.0 hours) spraying was done to the SFP4.

On April 23rd, bad weather interfered with the webcam, until 10:00, by then steam was seen rising from unit 4. Water spray to SFP4 started at 12:30 and ended 16:44 (4.3 hours).

By early morning of March 24th, the webcam showed much steam coming from unit 4. The steam intensified until about 8:00, then gradually diminished, until noon. From 12:25-17:07 (4.6 hours) spraying was done to the SFP4. While the spraying was ongoing no apparent smoke could be seen rising on the webcam, however on the last daylight webcam of April 24th (18:00) it appears unit 4 had resumed steaming.

On April 25th (today), little or no steam has been seen on the webcams, and there are so far no information in Tepco press releases on any spraying to the SFP4.

 

[DSamsom]

..
On April 22nd, the webcam showed steam coming from unit 4 from 16:00, intensifying by 17:00. From 17:52 to 23:53 (6.0 hours) spraying was done to the SFP4...

Thanks for this. What's the link to this webcam?

 

[jlduh]

This link (but now it's night!)

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

 

[Uagrepus]

Hello at all,

not my language, so I keep it short. My guess is, they opened the wall of No.4 in the past ("the green plug") and removed the staircase later:

http://img717.imageshack.us/i/holestairway.jpg

 

[Bodge]

Do you want to see some fun info from Reactor 4?

http://atmc.jp/plant/rad/?n=4

5000 Sieverts / hour in the suppresion chamber.

Down to 4250 Sieverts / hour today

N.B. You must alter the site's url to find this info: reactor 4's data is not given a hyperlink.

 

[MadderDoc]

*Ponder*

@|Fred

 

[ascot317]

Do you want to see some fun info from Reactor 4?

http://atmc.jp/plant/rad/?n=4

5000 Sieverts / hour in the suppresion chamber.

Down to 4250 Sieverts / hour today

N.B. You must alter the site's url to find this info: reactor 4's data is not given a hyperlink.

See, reactor 4 was in maintenance, there's no need for these sensors to work.
That you had to alter the url should tell you something.

 

[fluutekies]

Great thread! Long time lurker and first post.

Do you want to see some fun info from Reactor 4?

http://atmc.jp/plant/rad/?n=4

5000 Sieverts / hour in the suppresion chamber.

Down to 4250 Sieverts / hour today

N.B. You must alter the site's url to find this info: reactor 4's data is not given a hyperlink.

Nice hack! Why are #5 & #6 so high? (up and down)?

Hello at all,

not my language, so I keep it short. My guess is, they opened the wall of No.4 in the past ("the green plug") and removed the staircase later:

http://img717.imageshack.us/i/holestairway.jpg

Great finding & explanation!

 

[MadderDoc]

This link (but now it's night!)

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

For convenience I have cached copies of webcams since the morning of March the 11th at:
http://gyldengrisgaard.dk/tepcowebcam/
(please allow for somewhat slow loading, I'm at the end of a 0.5 Mbit/s connection)

 

[Jorge Stolfi]

To people drawing squares on the wall of Unit #4: beware that the floors inside do not have the same height. The 3nd floor is level with the roof of the building in front, and its ceiling is very low, just matching the height of the "hole". In the post-explosion pics, the "hole" is all but hidden behind a pile of rubble from the façade. the 4rd floor is slightly taller, the two rows of panels on the service floor (5th) taller still.http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/blueprint/un3_building_cut_N_2.png

Edit: fixed the floors above (3rd and 4th)

 

[Caniche]

Most curious . Perhaps someone could offer a plausible explanation for the enormous discrepancies in the emissions figures?

I131 - NISA estimate total emissions to 12/4/2011 = 130,000 TBq
NSC = 150,000 TBq
CTBT network analysis estimate total emission to 15/3/2011 = 400,000 TBq

Likewise for

C137 - NISA = 6100 TBq to 12/4
NSC = 1200 TBq t0 12/4
CTBT = 33,000 TBq to 15/3

Sorry to be a bore but can I bump this. No answers yet and it does seem critical. Do we posses reliable monitors? or is the interpretation of the data more of an art than a science?
(yes the source was ZAMG , but they have changed their data presentation recently so don't forget to add 16 zeros to any figure that appears as X t0 the power 16;-) )