Japan earthquake - contamination & consequences outside Fukushima NPP

zapperzero

http://www3.nhk.or.jp/daily/english/20120220_26.html

partial results of an ongoing survey in Fukushima:

40% of residents from 3 affected municipalities got more than 1 mSv in the first four months after the accident.

Highest dose received was 23 mSv.

tsutsuji

http://www3.nhk.or.jp/news/genpatsu-...5_sokutei.html The ministry of education and science is releasing a new online map with real time radiation measurements in 2700 places such as schools and parks in Fukushima prefecture. A trend graph is provided for each sensor.

http://radioactivity.mext.go.jp/ja/i...2012022114.pdf presentation of the new real time map.

http://radiomap.mext.go.jp/ja/ The new real time map.

[It is a bit disappointing that they don't say the height of each sensor. All they say is "either 50 cm or 1 m". Another problem is the 3 microsievert/hour upper limit of the trend graph. With about 9 microsievert/hour, the trend graph of Namie's prefectural high school is not available as it is higher than 3 microsievert/hour]

Astronuc

http://hps.org/fukushima/

The Health Physics Society has a lot of relevant information on the health and environmental effects of radiation.

tsutsuji

http://www3.nhk.or.jp/news/genpatsu-...ibakuryou.html Results of the external radiation estimates for 14,680 people of Iitate, Namie and Kawamata, for the 4 month period after the accident. Among the 9747 people who are not nuclear workers, 4111 are above 1 mSv, 71 are above 10 mSv. The highest is a woman with 23 mSv. She evacuated once, but came back and lived for 3 months in the planned evacuation zone.

http://ajw.asahi.com/article/0311dis...AJ201202220028 "It measures air radiation levels of gamma rays at a height of 50 centimeters above the ground in kindergartens, day care centers and elementary schools and at a height of 1 meter above the ground at junior high and senior high schools and at other public facilities."

http://www.bbc.co.uk/news/science-environment-17124909 "research cruise in June last year led by the Woods Hole Oceanographic Institution (WHOI).The initial findings were presented to the biennial Ocean Sciences Meeting. "

http://www3.nhk.or.jp/news/genpatsu-...1430_100m.html The ministry of environment is releasing an interim report with a 100 metre mesh radiation map. It was started in November and displays the measurements in 7963 locations. Some of the areas in the central part of Iitate village that were marked as above 20 mSv/year in the helicopter maps were found below 20 mSv/year. The highest location is in the Yamada district of Futaba with 89.9 microsievert/hour (472.5 milisievert/year). The final report will be released next month. It will be used by local governments to plan decontamination, and by the national government to revise the boundaries of the evacuation zones.

http://www.env.go.jp/press/press.php?serial=14870 Detailed monitoring pursuant of decontamination special law (interim report)

zapperzero

Xenon-133 and caesium-137 releases into the atmosphere from the
Fukushima Dai-ichi nuclear power plant: determination of the
source term, atmospheric dispersion, and deposition
http://www.atmos-chem-phys.net/12/23...-2313-2012.pdf

tsutsuji

http://sciences.blogs.liberation.fr/...enne-irsn.html The French IRSN will publish a report on the Fukushima accident on the first anniversary of the accident [that must be on 11 March 2012].

nikkkom

"radioactive noble gasses : 6550 PBq (petabecquerels =10^15 Bq) (≈ Chernobyl), mostly xenon 133 (133Xe, period of 5,3 years)"

Xe-133 period is 5.2 days, not years.

tsutsuji

oops. sorry for the mistake.

http://www3.nhk.or.jp/news/genpatsu-...228/index.html A ministry of Economy and Industry study group is proposing a 100 Bq/kg safety limit for crushed stones.

http://www3.nhk.or.jp/news/genpatsu-...40_ochiba.html The Forestry agency made a study of fallen leaves in 400 locations in Fukushima Prefecture. In a location 10 km west of the plant and in a location 25 km north-west of the plant the radiations were both 4,440,000 Bq/kg.

http://www3.nhk.or.jp/news/genpatsu-...305/index.html An NHK survey found that there is a strong suspicion that at least 5 people left isolated in the evacuated zone died of starvation. The body of a man in his seventies was found at the end of March on the second floor of a house located 5 km away from the plant. The first floor had been damaged by the tsunami. A woman in her sixties was found dead in her house in April. She had a chronic disease affecting her legs. Her house did not suffer large tsunami damage. All five bodies were thin as a consequence of losing weight. The police and the doctors who examined the bodies say that there is a high probability that they weren't able to evacuate by themselves or to call for help. The NHK found that the detailed causes of the bodies found on tsunami sites were not researched using autopsies and were counted as "drowned". The doctors say that it is possible that among the people counted as "drowned", some of them might have survived for some time and died later from a different cause. Several evacuation zone firemen testify that before the rescue operations were halted, they had heard voices of survivors trapped in the tsunami debris, calling for help. Yoshihisa Takano, a Namie fireman, recalls that after hearing voices and rattling in the debris, he went back to the town hall to call for help, but there weren't people or equipment available, and another tsunami warning came. Finally it was decided to resume rescue operations the next morning. But the next morning, the evacuated zone was extended to the 10 km range, and evacuating the 10 km range became the priority. "I am still regretting today that we did not go to rescue this/those person(s), although I had told him/them "we will come tomorrow for for help, please wait"".

http://www3.nhk.or.jp/news/genpatsu-...850_gashi.html According to an NHK survey, the number of patients from evacuated hospitals who died during the long hours of evacuation or after their health deteriorated shortly after evacuation is at least 68. Asked about the 5 people strongly suspected of having died of starvation, isolated at home or near their homes, the NISA said it is studying a revision of the guidelines so that cities and villages have to specify in their evacuation plans the method by which they will respond to the citizens who need help to evacuate, and the method by which they check that no citizen is left behind.

tsutsuji

http://www.yomiuri.co.jp/feature/201...OYT1T01065.htm According to the Japan Agency for Marine-Earth Science and Technology, the quantity of Cesium that flowed into the ocean is 6 times as much as the Tepco estimate. It was announced at a research reporting conference at JAEA on 6 March. This research is based on seawater samples in 500 locations and a simulation of cesium migration until 7 May 2011. The contaminated water that flowed into the ocean was estimated between 4200 and 5600 TBq of cesium. The cesium released into the atmophere that sunk into the ocean (with the rain, etc.) is estimated between 1200 and 1500 TBq.

etudiant

These estimates don't square with the IRSN estimates of about 58,000 Terabequerels of cesium. We are out by almost a factor of 10.
Also, the IRSN mentions very large early releases of tellurium, which presumably decay to iodine in short order. These were not mentioned afaik in the various TEPCO releases. Were they summarized with the iodine levels?

clancy688

I think they do. You compare the wrong levels.

First of all, IRSN claimed that 58 PBq of Cesium were released via the atmosphere, not water. Moreover, those 58 PBq are all kinds of Cesium - 137 (21 PBq), 136 (9.8 PBq) and 134 (28 PBq).

But there's another estimate for release into the ocean. They claim that 27 PBq of Cesium-137 was released into the sea.
TEPCOs initial estimate was 4.2 to 5.6 PBq C-137 released. Six times that estimate would be 25.2 to 33.6 PBq. Which puts it right into the vicinity of the IRSN estimate.

etudiant

Thanks for the clarification.
I'm still confused. If 58 PBq of cesium is near correct, even after removing the ocean water release of 33 PBq, there are 25 PBq of airborne release to be accounted for.
Does that mean that TEPCO's initial estimate of 1.2 to 1.5 PBq was off by a factor of 15?

clancy688

There's only 21 PBq of C137 aerial releases in that estimate, and as far as I understand, it doesn't include the water release. For IRSN, it's 21 PBq C137 air + 27 PBq C137 sea, which gives us a total release of 48 PBq C137 (~60% of the Chernobyl C137 air release).
The water release number of 27 PBq can't include aerial deposition since it was calculated with water samples taken 500 m away from the plant.

I don't know where those 1.2 to 1.5 PBq come from, but I'm sure it's not TEPCO. Afaik TEPCO never gave us an estimate for atmospheric releases. It's probably a NISA or NSC number.
The first total atmospheric release estimates coming from NISA and NSC when they announced INES 7 was 6.1 and 12 PBq C137. Since then they upgraded their estimates to 15 and 11 PBq. But that's still way off the real numbers.

IRSN estimates, as mentioned above, 21 PBq. There's a recent paper created by atmospheric scientists which goes even further - they estimate that 20.1-53.1 (36.6 would be the middle value) PBq C137 was released into the atmosphere. Of which 80% was deposited over the Pacific.
So you get 27 PBq + 0.8 * 36.6 PBq as the total value of C137 which ended up in the Pacific.

tsutsuji

I don't know the details of the IRSN estimate, but one possibility is that the 27PBq include some cesium that was carried by air, and later sunk into the sea with the rain.

Where have the IRSN's 21 PBq of airborne cesium fallen ? onto the land (on Japan, on the Asian continent ? on the American continent ? etc.) or into the sea (into the Pacific Ocean ? into the Indian Ocean ? etc. ) ?

The amount of "between 1200 and 1500 TBq" from the JAMSTEC study mentioned in the Yomiuri article is perhaps not a quantity over the Pacific Ocean as a whole, but only over the part of the sea where the 500 sea water samples were taken ?

The Yomiuri article quotes Yasumasa Miyazawa, who published the following :

http://www.terrapub.co.jp/journals/G...e/460100e1.pdf Dispersion of artificial caesium-134 and -137 in the western North Pacific one month after the Fukushima accident, Geochemical Journal, 46, e1-e9 (Online published January 16, 2012)) [English]

The above paper relies on

http://www.sciencedirect.com/science...65931X11002463 Daisuke Tsumune, "Distribution of oceanic 137Cs from the Fukushima Dai-ichi Nuclear Power Plant simulated numerically by a regional ocean model", Journal of Environmental Radioactivity, Available online 8 November 2011

zapperzero

iirc it was something like almost 80% Pacific, 20% over Japan and some insignificant bit for the rest of the world.

clancy688

I don't think so. The 27 PBq estimate was calculated with water samples taken 500 metres away from the plant. So aerial deposition is most likely not included, since it happened over a surface of millions of square kilometres.

zapperzero

I wouldn't be so sure about that. All it takes is some rain, or an atmospheric inversion day.