Japan Earthquake: nuclear plants

tsutsuji

http://elpub.wdcb.ru/journals/rjes/v...11ES000503.pdf (I.N. Tikhonov, "2011 Mega-earthquake on 11 March 2011 in Japan and aftershock process dynamics' development", Russian Journal of Earth Sciences, written in April 2011, published in May 2011) Choosing to focus on the earthquakes with a magnitude greater than 7.6, this article provides on page 4 two simple maps of the historical seismic data in North-East Japan in support of the view that "the existence of a seismic gap at the length of ~ 800 km was retrospectively revealed, located to the south of 39°N and filled recently with aftershocks of the mega-earthquake".

There is also a small screen below that one. It is marked with 水位計リール　"water level gauge reel".

The word "dose" can be read. The figures are consistent with the values in milisievert/hour provided at http://www.tepco.co.jp/en/nu/fukushi...10711_04-e.pdf which also maps the robot trajectory inside the reactor building.

The analysis of the air samples taken by the robot are available on http://www.tepco.co.jp/en/nu/fukushi...10711_03-e.pdf . It shows that the air can't be breathed.

A video showing the outer view of quince during a test was provided in June : http://www.tepco.co.jp/en/news/11031.../110620_25.zip (4.6 Mb).

Bandit127

I have to use Google and I hope it makes sense.

我々の知識への貢献は、測定を超えた価値を持っていま

Thank you Tsutsuji for all your posts.

Jim

Atomfritz

There was already much sub-atmospheric pressure. Just see Jorge Stolfi's great diagrams.
To me it looks not much different from that what happens when you let a kettle with a bit of water cool down after boiling.
In fact this makes me somewhat optimistic that there is probably no big danger of melt-through. Tepco probably just wants to make sure that there is insufficient oxygen so that the reactors don't poop again.

German Spiegel says that it has been shut down because the emergency boron injection system has been found to have too little pressure. Dunno what is correct.

Sand bags just for rain?!? Sounds more like some flooding. How much liters per sq.m. is normal in Japan?!?

Just my 2 ct.: When scaling up from liters (La Hague) to cubic meters (Fukushima Daiichi) they forgot to include "Luftabscheider" (don't know english word, sorry. These devices keep tubes and such free from air and gases, preventing them from clogging. Can anyone please tell how this is called in english? -thanks!)

Barneysee

Deaerator (removes the air)

joewein

Here's a rainfall map from a typhoon two months ago:

http://www.nasa.gov/images/content/5...-TRMM_full.jpg

As you can see, some areas got in excess of 100 mm during that one storm (i.e. 100 l per m²), two months' worth of rainfall in Germany. Landslides during typhoons are quite common in Japan.

turi

http://www.tepco.co.jp/en/press/corp...1071708-e.html
Interesting. Is the Clean up Water System now being used for the spent fuel pond? I can't really see them using it for cooling the reactor as such.

Atomfritz

Thanks all for the info!
This really worries me.
At least, if there such "rains" are regular, I no longer wonder why the roof of Unit 3 so quickly looked like having been cleaned with a big water hose.
I could imagine if such masses of water are going to splash down through the staircases into the lower floors, the radiation measures done recently could be obsolete soon again.


(image taken from this Tepco pdf)

I am really surprised of this sudden "appearance" of a roof for Unit 3.
Is Tepco ahead of their "official" roadmap, or did they just realize that they do not want big rainwater streams in the reactor buildings?

Attached Thumbnails

 

Caniche

Very comforting ,all neat and tidy no detritus not even a stray roof spar. Bit worried about the lack of blue goo that keeps down the wind blown poison though, thought they'd sprayed all over the site a dozen times just to be sure.Maybe its a projected image like estate agents use

tsutsuji

I think Tepco is merely showing the roof sheets before installing them on a roof, saying the sheets on the picture are intended for unit 3.

Judging by the greenish color of the reactor building in the background, this must be reactor No.5 or No. 6. (You can compare the bluish color of reactors 1~4 with the greenish color of reactors 5~6 on http://cryptome.org/eyeball/daiichi-npp2/pict55.jpg ). I think the background of http://www.tepco.co.jp/en/news/11031...s/110717_1.jpg (or http://www.tepco.co.jp/en/nu/fukushi...10717_01-e.pdf ) is, from left to right : the Futaba and Yonomori power lines, unit 5 reactor building and unit 5 turbine building.

The rain from typhoon 6 has not started pouring. If typhoon 6 ever comes to Fukushima, it will be after it reaches Tokyo, and it is not expected in Tokyo before July 20th : see http://www3.nhk.or.jp/news/html/2011...272451000.html

This news is about the other plant, Fukushima Daini, located a few kilometers south from Fukushima Daiichi.

turi

Right. Sorry for the mixup. And thanks for all your posts, they're very informative.

Gary7

Regarding the "roof", the Tepco press release for today says:

As precaution against rain for the exposed top section of the turbine building for Reactor #3, construction of a temporary roof was begun at 8:30am (July 18th).

(original Japanese) ７月18 日午前８時30 分、３号機タービン建屋屋上開口部の雨水対策として仮屋根の取り付け作業を開始しました。

Also mentions a worker who was injured in a fall from an electric pole/pylon today, and was transported to hospital via helicopter.

http://www.tepco.co.jp/nu/f1-np/pres...a/bi1632-j.pdf

tsutsuji

I think both are correct :

See also the diagram released by Kepko showing the accumulator that broke down at Ohi NPP : http://www.kepco.co.jp/pressre/2011/...0716_1j_01.pdf (ぼう酸水=borated water ; 窒素=nitrogen ; 弁=valve ; 蓄圧タンク= accumulator ; 水位計=water level gauge ;　圧力計=pressure gauge)

Here is Kepko's 16 July press release :

About Fukushima Daiichi NPP :

http://www.yomiuri.co.jp/science/new...OYT1T00495.htm there is more than one hole in the roof of unit 3 turbine building. The largest is 14 x 11 m wide. The repair is made with 3 steel sheets of 5 x 16 m each. While this repair is done today, the other holes will be repaired tomorrow. What is feared is that if too much rain water pours through the holes, the water accumulated in the turbine building might overflow and leak into the sea.

http://www.asahi.com/special/10005/TKY201107170417.html this is an assessment of the "step 1" of the roadmap. The following are marked with the "〇" (completed) symbol :

〇 closed loop reactor cooling
〇 starting the water treatment facility
〇 nitrogen injection
〇 SFP cooling (implemented in advance at units 2 & 3)

Then we have the "△" (under execution) symbol

△ reinforcement of unit 4 against earthquakes
△ hyperthermia prevention
△ assessment of the radiological status of the environment
△ removing debris

Then the "×" (execution impossible)

× repair the containment vessels (the locations of the damages are not even known)

It is expected that the government will announce tomorrow that they will start to study the lifting of some of the evacuation-prepared areas, based on the prerequisite that the nitrogen injection prevents hydrogen explosions and that new radiological emissions are curbed at a low level.

http://www3.nhk.or.jp/news/genpatsu-...5_suiryou.html On 17 July afternoon, Tepco changed the pump that injects water into both unit 1 and unit 2 reactors. Its maximum flow rate is 20 m³/hour. On the morning of 17 July, the flow rate injected into unit 1 declined to about 3 m³/hour instead of the expected 3.8 m³/hour, ringing an alarm. The flow rate had to be ajusted again to 3.8 m³/hour. While nothing similar happened on the unit 2 line, it is the third time this sort of trouble happens at unit 1. For that reason it is believed that there is dirt in the piping to unit 1.

Joe Neubarth

Iodine 131 Four months after Reactor Three Blew???? One hundred and twenty some days after Reactor Three Building blew, and they are still finding I-131 ?????????

This is very frightening. As previously stated, Iodine-131 being very radioactive has a rapid half life. Every week or so half of it is gone. After 80 days it should be almost impossible to detect. Yet, here we are FOUR months after the BIG Detonation of Reactor Three and we are still seeing large amounts of Iodine 131 in water samples.

Am I wrong or should this not be happening???

Tokyo gov’t finds iodine-131 levels up to quadruple cesium levels in water reclamation centers.
July 18th, 2011 at 07:35 AM


Measurements of radioactivity in sewage treatment, etc., Sewer Authority (Tokyo), July 15, 2011:
http://translate.google.com/translat...i/infn0533.htm

robinson

It may mean the amount of Iodine that was released was far higher than was reported.

Atomfritz

Maybe just a "spelling mistake" - the long-term iodine measurements after emissions usually regard I-129 (halftime 15 mill yrs).

Thanks!
This makes me feel understand the differences of Xinhua and Spiegel report, both seem correct to me even if the first impression looks quite different.

The article Tsutsuji quoted says that only the biggest hole in T/B roof is 11x14 meters and there are others. On the satellite photos these holes seem soo small!
And that they appear to have set up some kind of harbor near units 5+6, this seems very sensible. They are really doing much much work, without any kamikaze like in Russia.

I well understand that they want to get the holes closed before the tsunami comes. Could else be like waterfall sinks.
And, the rain decontaminating the roofs so probably will just conveniently flow into the ocean. Nice!

joewein

I have never seen I-129 mentioned in Tokyo water-related data.

The numbers for levels in drinking water published by the city only listed I-131, Cs-134 and Cs-137:
http://monitoring.tokyo-eiken.go.jp/...past_data.html

Same for most seawater figures released.

With its long half life it probably doesn't contribute a lot of becquerels relative to its weight, so I don't think a mixup with it would explain those becquerel figures.


Given that I-131 levels in early April where an order of a magnitude higher than cesium levels, they should have reached parity around early May. By July 4-5 when the water sludge was measured, another 8 half lives of I-131 should have passed, so I-131 should be two orders of a magnitude below cesium.


If in this particular source they were at similar levels, one would assume chemical reasons for that, i.e. cesium didn't precipitate with the mud as much iodine did. Cesium salts should be highly soluble (similar to potassium salts) and it would never occur in elementary form outside the lab. Iodine does have insoluble salts (such as silver iodide) and in elementary form is not particularly water soluble.

tsutsuji

http://www3.nhk.or.jp/news/html/2011...286881000.html With the purpose of recovering the 50 m³/hour flow rate from the decline to 37 m³/hour, the water treatment facility had been shut down on the morning of 15 July to make repairs such as bleeding air and changing hoses for ones with lesser resistance, and a 39 m³/hour flow rate had been achieved. However on the morning of 18 July the flow rate had dropped to 37 m³/hour again. Tepco admits that it ignores the cause of the problem.

http://www3.nhk.or.jp/news/genpatsu-...25_kangae.html The expectation that the government would define more precisely today what is meant by the "cold shutdown" that should lead to a lifting of the 20 km range no-entry zone has been deceived. The definition provided by the government today remains vague, saying the RPV bottom temperature must be around 100°C and human exposure to radiation must be largely curbed. This is far from a concrete definition of radioactive substances and radiation dose limits.

http://mainichi.jp/select/weathernew...40126000c.html The exposure of two workers who repaired the big hole on unit 3 turbine building roof yesterday passed 10 mSv, with a maximum of 12 mSv. Today the plan is to repair one 5 m x 2 m oval-shaped hole and a number of skylights blown up by the explosion, and to install sandbags preventing water to flow into a gutter whose down pipe is damaged.