Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[clancy688]

That's interesting. The position of the Torness nuclear power station in eastern Scotland, and other British coastal reactors, did not take account of the Storegga Slide, which caused a large tsunami in about 6100BC.

I don't know when the Storegga Slide was discovered, but it hasn't been so long afaik. Perhaps the plants were built before they knew of the Slide.

P.S.
In the novel "The Swarm" by Frank Schätzing, a devastating Storegga slide is triggered, wrecking all european north sea coasts and inundiating several NPPs, thus disabling the cooling systems and leading to beyond design basis accidents. One character is even commenting on how stupid it was to build NPP cooling systems on sea level. ;) (The novel is from mid 2004)

 

[biggerten]

That's interesting. The position of the Torness nuclear power station in eastern Scotland, and other British coastal reactors, did not take account of the Storegga Slide, which caused a large tsunami in about 6100BC.

"The Storegga Slide occurred 8200 years ago and was the last megaslide in this region where similar slides have occurred with intervals of approximately 100 ky since the onset of continental shelf glaciations at 0.5 Ma."

"The Storegga Slide (Fig. 1) is one of the largest submarine slides discovered, and has been known since the 1970s"

from "Explaining the Storegga Slide", http://www.ig.uit.no/geo3128/02-Bryn_etal_MPG_2005.pdf

Interesting stuff, what one can learn.

On a side note, if I may, I'd like to thank tsutsuji for keeping us up to date. I really, really, appreciate it.

 

[Barneysee]

It is four months to the day since Unit three blew up.

And there is some recent progress in the #3 thread.
https://www.physicsforums.com/showthread.php?t=505630&page=24

 

[tsutsuji]

http://www.asahi.com/national/update/0714/TKY201107140324.html (same link as yesterday, but it was updated) For the repair under the 100~150 mSv/h radiation at the Areva facility on 14 July, they created a 10 people team, each one working no longer than 2 minutes. A test run was started at 3 PM and the facility was started again at 6 PM.

http://www3.nhk.or.jp/news/html/20110715/t10014229731000.html The water treatment facility was stopped again at 5 AM on 15 July in order to investigate the reason why the flow decreased to 37 ton/hour instead of the expected 50 ton/hour. The first 100 m³ of nitrogen have been successfully injected into unit 3.

http://www.jiji.com/jc/c?g=soc_30&k=2011071500409 It is suspected that the flow drop at the water treatment facility is due to air trapped in the pipes. The water spray at unit 2's SFP cooling system is broken down. SFP 2's temperature has risen to 40°C. Tepco has updated a control panel in order to enable the installation of the new Toshiba-IHI-Shaw water treatment system.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110714_06-e.pdf Diagram, pictures, details of the new Toshiba-IHI-Shaw (SARRY) water treatment system.

http://www.tepco.co.jp/en/press/corp-com/release/11071501-e.html [Main Gate monitoring post] "at 6:15 pm on July 14, we replaced with alternative portable monitoring post and was restored. We also confirmed monitoring data was at the same level as before the equipment failure."

http://www.tepco.co.jp/cc/press/11071507-j.html The valve on the line bringing water from the filtrate tank to unit 2 SFP cooling secondary circuit was closed. At 11:47 they opened the valve and the SFP2 cooling system was started again. A test run of unit 5 main RHR B system sea water pump was started at 10:16 AM. The water treatment facility was started again at 02:21 PM

http://www.nikkei.com/news/headline...19481E3E7E2E1868DE3E7E2E5E0E2E3E39797E0E2E2E2 During the water treatment facility shutdown this morning they bleeded air from the pipes and changed some hoses, but the flow had little improved, being still a little below 40 ton/hour after the facility was started again this afternoon.

http://www.yomiuri.co.jp/science/news/20110715-OYT1T00969.htm Tepco is taking 570 tons of fresh water from the river to raise the water level in the fresh water tank. No water had been taken in the river for two weeks. Yomiuri says this is due to the water treatment facility's poor performance, but I am not sure I understand. Have they really run out of stored decontaminated water ? On 12 July, they had 4563 m³ in the desalinated water receiving tank, according to http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110713e10.pdf . If the 3 reactors together need 400 m³ every day, this was enough to cover more than 11 days.

 

[swl]

http://www3.nhk.or.jp/news/html/20110715/t10014229731000.html The first 100 m³ of nitrogen have been successfully injected into unit 3.

Does this mean that they have now evacuated an additional 100 cubic meters of contaminated gas from the reactor?

Does anyone know the flow rate? Also, at this [STRIKE]late stage[/STRIKE] not so early stage in the accident, is hydrogen production likely to remain problematic? As far as I can tell, there should be little trouble of hydrogen collecting within the reactor 3 building. Are they just trying to keep oxygen out of the (mostly empty?) RPV?

Also google tranlates the above to read "According to TEPCO, significant changes in the amount of external radiation that is observed." But my elementary knowledge of the written language seems to indicate that "東京電力によりますと、外部の放射線の量に目立った変化は見られないということです。" means Tepco says they have not been able to detect a change in the external radiation levels. I don't have access to my lovely (carbon) translator at the moment, so I'm not sure...

 

[tsutsuji]

Does this mean that they have now evacuated an additional 100 cubic meters of contaminated gas from the reactor?

Does the following answer your question ?

[Regarding the injection of nitrogen to the reactor containment vessel of Unit 3](2) Environment impact due to radioactive material released from the PCV by the injection

The radioactive material does not newly shift to the vapor phase part of the PCV by the injection of nitrogen. Thus the amount of vapor per a certain period released from the PCV increases due to the injection of nitrogen and the steamy condensation prevention effect, however there is not a possibility that the nitrogen injection affects the surrounding environment.

http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110711e11.pdf

Does anyone know the flow rate?

http://www.nikkei.com/news/category...39797E3E2E2E2;at=DGXZZO0195165008122009000000 14 m³/h of nitrogen will be injected into unit 3

For the google translation problem you mentioned, try this link : http://translate.google.com/#ja|en|外部の放射線の量に目立った変化は見られない

 

[Barneysee]

Does this mean that they have now evacuated an additional 100 cubic meters of contaminated gas from the reactor?

LOL

is hydrogen production likely to remain problematic?

It probably remains a possibility that an OX/H reaction could still go bang ala unit 2. If it did, TEPCO would sure look foolish.

I think I would be pumping nitrogen too if I were them.

 

[joewein]

is hydrogen production likely to remain problematic? As far as I can tell, there should be little trouble of hydrogen collecting within the reactor 3 building. Are they just trying to keep oxygen out of the (mostly empty?) RPV?

The talk about nitrogen injection started as soon as they got cooling water flow going again and especially after they formulated their plan of bringing all three reactors to "cold shutdown" (whatever that means for reactors as wrecked as that). If the temperature drops below boiling, as per definition of cold shutdown, then there is no steam pressure that would keep external oxygen out, so they were concerned about any lingering hydrogen from the zirconium reaction mixing with air, with the containments having lost air tightness. If the cooling water condensates steam in the containment, it could create a vacuum that sucks in air.

I am not sure how much of that hydrogen could be left by now. A lot of cooling water must have boiled into steam and displaced hydrogen, diluting it further and further.

On the other hand, as long as there are both high levels of radioactivity and water in the plant, hydrogen + oxygen production of from radiolysis of water remains possible, especially if it's hot enough (at least in places) for the gases to escape with steam from boiling liquid before they have a chance of recombining.

Injecting nitrogen is the safe thing to do if you can't be sure about how much hydrogen is remaining or is yet to be produced from radiation.

 

[tsutsuji]

http://news.xinhuanet.com/english2010/world/2011-07/16/c_13988710.htm "Japan's Kansai Electric Power Co. said on Saturday it planned to manually shut down the No.1 reactor at its Ohi nuclear power plant in western Japan's Fukui Prefecture due to technical glitches with its cooling system"

http://sankei.jp.msn.com/affairs/news/110716/dst11071612160010-n1.htm Tepco announced the safety measures against the Typhoon No. 6 at Fukushima Daiichi. The megafloat filling operation will be stopped. Big swell being expected, hoses will be removed and equipments will be tightened with ropes. Roof sheets will be installed on turbine buildings, and sandbags will be installed around buildings to stop rain water.

http://www3.nhk.or.jp/news/html/20110716/t10014253181000.html Tepco has announced its plans for the July 2011 - January 2012 "step 2" of the roadmap. It was not expected to go beyond studying a ground water shielding wall, but it was decided to step up the pace and to start building the wall as part of "step 2". It is also planning improvements at the water treatment facility such as shortening or reinforcing the 4 km long pipes. A middle term schedule will be announced on 19 July. It is already known that the building of solid containment structures for reactors and the removal of fuel from the spent fuel pools will take about 3 years.

http://sankei.jp.msn.com/affairs/news/110716/dst11071611560009-n1.htm Two reasons are suspected for the decrease of the water treatment facility flow rate to 37 ton/hour instead of the expected 50 ton/hour : air trapped in pipes and foreign bodies. After bleeding air from pipes yesterday, the flow increased to 39 ton/ hour. Tepco keeps investigating.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110716_01-e.pdf Diagrams showing "Countermeasures against Decline in Flow Rate".

 

[Bandit127]

A new video (18.2 Mb) is available from Tepco's site from a 'quince' robot in Unit 2.

Towards the bottom of the video are windowed video feeds:
Left pane = wide angle overhead view of the robot.
Centre pane = rear facing
Right pane = front facing

At the top are some other bits & pieces, including temperature (centre). I don't know if the 2nd from the left is radiation, temperature, or what.

http://www.tepco.co.jp/en/news/110311/images/110716_01.zip"

 

[tsutsuji]

http://elpub.wdcb.ru/journals/rjes/v12/2011ES000503/2011ES000503.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".

Left pane = wide angle overhead view of the robot.

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

I don't know if the 2nd from the left is radiation, temperature, or what.

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/fukushima-np/images/handouts_110711_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/fukushima-np/images/handouts_110711_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/110311/images/110620_25.zip (4.6 Mb).

 

[Bandit127]

http://elpub.wdcb.ru/journals/rjes/v12/2011ES000503/2011ES000503.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/fukushima-np/images/handouts_110711_04-e.pdf which also maps the robot trajectory inside the reactor building.

A video showing the outer view of quince during a test was provided in June : http://www.tepco.co.jp/en/news/110311/images/110620_25.zip (4.6 Mb).

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]

The talk about nitrogen injection started as soon as they got cooling water flow going again and especially after they formulated their plan of bringing all three reactors to "cold shutdown" (whatever that means for reactors as wrecked as that). If the temperature drops below boiling, as per definition of cold shutdown, then there is no steam pressure that would keep external oxygen out, so they were concerned about any lingering hydrogen from the zirconium reaction mixing with air, with the containments having lost air tightness. If the cooling water condensates steam in the containment, it could create a vacuum that sucks in air.

I am not sure how much of that hydrogen could be left by now. A lot of cooling water must have boiled into steam and displaced hydrogen, diluting it further and further.

On the other hand, as long as there are both high levels of radioactivity and water in the plant, hydrogen + oxygen production of from radiolysis of water remains possible, especially if it's hot enough (at least in places) for the gases to escape with steam from boiling liquid before they have a chance of recombining.

Injecting nitrogen is the safe thing to do if you can't be sure about how much hydrogen is remaining or is yet to be produced from radiation.

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.

http://news.xinhuanet.com/english2010/world/2011-07/16/c_13988710.htm "Japan's Kansai Electric Power Co. said on Saturday it planned to manually shut down the No.1 reactor at its Ohi nuclear power plant in western Japan's Fukui Prefecture due to technical glitches with its cooling system"

http://www.spiegel.de/wissenschaft/technik/0,1518,774825,00.html" Dunno what is correct.

url]http://sankei.jp.msn.com/affairs/news/110716/dst11071612160010-n1.htm[/URL] Tepco announced the safety measures against the Typhoon No. 6 at Fukushima Daiichi. The megafloat filling operation will be stopped. Big swell being expected, hoses will be removed and equipments will be tightened with ropes. Roof sheets will be installed on turbine buildings, and sandbags will be installed around buildings to stop rain water.

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

http://sankei.jp.msn.com/affairs/news/110716/dst11071611560009-n1.htm[/URL] Two reasons are suspected for the decrease of the water treatment facility flow rate to 37 ton/hour instead of the expected 50 ton/hour : air trapped in pipes and foreign bodies. After bleeding air from pipes yesterday, the flow increased to 39 ton/ hour. Tepco keeps investigating.

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]

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

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

http://www.nasa.gov/images/content/555707main_20110602_Songda-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]

- At 11:40 am on July 17, the Clean up Water System of Unit 2 has been
restored.
* Clean up Water System (CUW): system to remove impurities in reactor
water and maintain the water quality; The system is also used to
control reactor water level by discharging redundant water from the
reactor during a regular inspection or reactor shutdown.

http://www.tepco.co.jp/en/press/corp-com/release/11071708-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!

...in excess of 100 mm during that one storm (i.e. 100 l per m²)

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 http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110717_01-e.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?

 

[Caniche]

(image taken from http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110717_01-e.pdf")

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 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?

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/110311/images/110717_1.jpg (or http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110717_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/20110717/t10014272451000.html

http://www.tepco.co.jp/en/press/corp-com/release/11071708-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.

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

 

[turi]

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

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/press_f1/2011/htmldata/bi1632-j.pdf

 

[tsutsuji]

http://www.spiegel.de/wissenschaft/technik/0,1518,774825,00.html" Dunno what is correct.

I think both are correct :

The functions of the ECCS accumulators are to supply water to the
reactor vessel during the blowdown phase of a loss of coolant accident
(LOCA), to provide inventory to help accomplish the refill phase that
follows thereafter, and to provide Reactor Coolant System (RCS) makeup
for a small break LOCA.
(...)
The accumulators are pressure vessels partially filled with borated water
and pressurized with nitrogen gas.
http://pbadupws.nrc.gov/docs/ML0916/ML091671716.pdf

See also the diagram released by Kepko showing the accumulator that broke down at Ohi NPP : http://www.kepco.co.jp/pressre/2011/__icsFiles/afieldfile/2011/07/16/0716_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 the manual shutdown of Ohi NPP unit 1 (decline of pressure at accumulator C)

Ohi NPP unit 1 (pressurized water reactor, nominal output 1,175,000 kW, nominal thermal power 3,423,000 kW) was undergoing a test run as part of inspection No.24 when the "high/low pressure, accumulator※ C" alarm was issued, at 10:46 PM, 15 July 2011.

When we checked the pressure gauge, instead of the normal 4.60 MPa, the pressure was 3.65 MPa, which is below the safety limit of 4.04 MPa. For this reason, we started bringing nitrogen using the nitrogen supply line at 11:20 PM and at 11:45 PM the pressure had risen back to 4.09 MPa, satisfying the 4.04 safety standard.

The supply of nitrogen was completed at 12:38 AM, today, and a visual inspection of the accumulator and nearby valves was undertaken, but no abnormality was observed. The pressure was stabilized at 4.08 MPa.

As we prioritize safety, in order to inspect the causes of the pressure decline and to implement countermeasures, we decided to start decreasing the output at around 1 PM today, and at around 9 PM we shut down the reactor.

This event is not causing radiological consequence to the environment.

※ Accumulator : Accumulators are tanks storing borated water. Each of the 4 primary cooling systems is installed with one. During a loss of coolant or other accident, when the pressure in a primary cooling system drops lower than the pressure of the nitrogen-pressurized accumulator, borated water flows into that primary cooling system.About the manual shutdown of Ohi NPP unit 1 :
http://www.kepco.co.jp/pressre/2011/__icsFiles/afieldfile/2011/07/16/0716_1j_01.pdf (pdf 28.6 KB)

Source : http://www.kepco.co.jp/pressre/2011/0716-1j.html (my translation)

About Fukushima Daiichi NPP :

http://www.yomiuri.co.jp/science/news/20110718-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-fukushima/20110718/0805_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/translate?act=url&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=ja&tl=en&u=http://www.gesui.metro.tokyo.jp/oshi/infn0533.htm

 

[robinson]

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

 

[Atomfritz]

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/translate?act=url&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=ja&tl=en&u=http://www.gesui.metro.tokyo.jp/oshi/infn0533.htm

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

See also the diagram released by Kepko showing the accumulator that broke down at Ohi NPP : http://www.kepco.co.jp/pressre/2011/__icsFiles/afieldfile/2011/07/16/0716_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)

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.

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).

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]

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

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/monitoring/w-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/20110719/t10014286881000.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-fukushima/20110719/0625_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/weathernews/news/20110719ddm003040126000c.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.

 

[joewein]

We have discussed the video in which Arnie Gundersen spotted what looked like a single "handle" for a fuel assembly in the debris-filled unit 3 pool.

I just noticed a picture of the same pool from probably the refueling last year on this page. Look for the picture labeled "Reactor 3 refueling - mox in top left corner".

http://www.houseoffoust.com/fukushima/tepco_pics/R3_mox_upperleft.jpg

If the black items are fuel assemblies then many are quite spread out over the pool, instead of in largely complete rows as in unit 4.

 

[Joe Neubarth]

I would think that spreading them out would be a prudent thing to do. I expect that the holding racks are very secure, but a more uniform distribution of weight would just make sense.

 

[Joe Neubarth]

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

I think many of us suspect that, simply because of the manner of revealing information that TEPCO established very early on.