Fukushima Japan earthquake - contamination & consequences outside Fukushima NPP

[tsutsuji]

Xe-133 period is 5.2 days, not years.

oops. sorry for the mistake.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120124/index.html As a countermeasure decided after finding that contaminated stones were delivered from a contaminated stone pit in Namie, the government is goint to check construction materials from the restricted zone. The namie stones were used in the concrete which was used to build a new appartment building in Nihonmatsu and high radiation levels were measured inside the appartments. A report will be issued within this month. Concerning the preparation of national safety level for construction materials, the nuclear disaster response headquarters said "it will take time to study it".

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120228/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-fukushima/20120304/1040_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-fukushima/20120305/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-fukushima/20120305/1850_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/20110316-866921/news/20120306-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]

http://www.yomiuri.co.jp/feature/20110316-866921/news/20120306-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.

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]

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.

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]

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.

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]

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.

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.

Does that mean that TEPCO's initial estimate of 1.2 to 1.5 PBq was off by a factor of 15?

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]

For IRSN, it's 21 PBq C137 air + 27 PBq C137 sea, which gives us a total release of 48 PBq C137

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/GJ/pdf/2012e/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/article/pii/S0265931X11002463 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

We then used a regional ocean model to simulate the 137Cs concentrations resulting from the direct release to the ocean off Fukushima and found that from March 26 to the end of May the total amount of 137Cs directly released was 3.5 ± 0.7 PBq ((3.5 ± 0.7) × 1015 Bq).

 

[zapperzero]

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. ) ?

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 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.

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 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.

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

 

[tsutsuji]

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.

That's right. The IRSN's 27 PBq are not including aerial deposition.

http://www.irsn.fr/FR/Actualites_pr...ident_Fukushima_sur_milieu_marin_26102011.pdf page 7-8 : " [airborne] Cs 137 deposited on the sea over an 80 km range [from the plant] is 76 E12 Bq (...) [or] 0.3% of the Cs 137 radioactivity in the sea".

See also http://www.irsn.fr/FR/Actualites_pr...ident_Fukushima_sur_milieu_marin_26102011.pdf page 6 and 7 where they say that their new (October) estimate is twice their own July estimate, and 20 times the Tepco estimate. What they revised between July and October was their assumptions about the vertical distribution.

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.

http://www.irsn.fr/FR/Actualites_pr...ident_Fukushima_sur_milieu_marin_11072011.pdf page 3 quotes the Japanese government's report to IAEA in June, where 4.7 PBq is the total of Cs137, Cs134 and I131 directly poured into the sea. According to that report, Cs137 alone is 0.95 PBq.

So I think that what the Yomiuri means by "six times as much as the Tepco estimate" is that 0.95 * 6 = 5.7 PBq which nearly equals the upper limit of the "between 4200 and 5600 TBq" mentioned in the latest JAMSTEC study.

 

[tsutsuji]

As for Fukushima, nobody died, that's right.

As mentioned by the NHK articles I mentioned above in https://www.physicsforums.com/showpost.php?p=3799632&postcount=501 , the evacuation of the population surrounding Fukushima Daiichi is suspected to be a contributing factor to the death of at least 68 + 5 = 73 people, among other factors such as a poor health, or having one's houses' first floor destroyed by a tsunami.

 

[r-j]

The new paper shows that minute quantities of plutonium from Fukushima have spread far from the plant. In samples taken to the northwest and in the J-Village, where workers live, the authors found trace amounts of plutonium in the surface soil (see map). Looking at the ratio of plutonium-241 to plutonium-239, they were able to conclude that the plutonium came from Fukushima rather than other sources, such as old nuclear-weapon tests.
...
Nevertheless, the measurements are interesting. The distances at which the team finds the material imply that plutonium was ejected during the hydrogen explosions in the first days of the crisis. And the relatively low levels (around 10,000 times lower than Chernobyl) suggest that the heavily shielded concrete casings around the reactors did offer some protection from the worst of the fallout.

http://blogs.nature.com/news/2012/03/plutonium-spotted-far-from-fukushima.html

 

[tsutsuji]

As seen above in this thread ( https://www.physicsforums.com/showpost.php?p=3802228&postcount=511 and above), there seems to be a large range of contradicting estimates as regards how much radioactive substances were released into the sea :

* The Tepco estimate
* 6 times the Tepco estimate (JAMSTEC)
* 20 times the Tepco estimate (IRSN)

This variation seems to be further confirmed by the following :

http://edition.cnn.com/2012/03/10/opinion/buesseler-fukushima-ocean/?hpt=hp_t3 Ken Buesseler is a Senior Scientist at the Woods Hole Oceanographic Institution : "There is also little agreement on exactly how much radioactivity was released or even whether the fires and explosions at the power plant resulted in more radioactive fallout to the ocean than did direct releases of radioactivity caused by dumping water on the reactors to keep them cool."

 

[mheslep]

WSJ article yesterday summarizing radiation impacts. Authors Hayaskhi, Dvorak, Hotz

Experts cited:
o Kathryn Higley, Oregon State, specialized in tracking radiation in the environment.
o Toshiso Kosako, Tokyo U., radiation protection (resigned in April as adviser to PM Kan)
o Shunichi Yamagarbagea, Fukushima Medical U, radition impact on human health
o US EPA
o TEPCO
o Timothy Mousseau, U South Carolina, radio ecologist.
o Tatsuo Aono, Japan's National Institute of Radiological Sciences

Lead sentence:

A year after the Fukushima nuclear accident, the emerging consensus among scientists is that its effects on physical health and the environment have so far been minimal. There have been no reported radiation-related deaths or illnesses from the accident, even among workers who faced very high exposure.

Dose details (US annual background 3msv, nuclear worker safety limit 100 msv):
o Survey 10k people in three high risk towns:
<1msv 58%
<5msv 95%
>15 msv 23 people

o Fukushima Plant, 20k workers:
>100msv, 167 workers
>250msv, 6 workers, highest dose 679 msv

Other details:
o Bird populations around Fukushima as of last July dropped by a third, without causal link yet.

o Thyroid problems, including cancer, future long term predictions (by Kosako, Tokyo U): 300 to 500 people.

 

[tsutsuji]

Dose details (US annual background 3msv, nuclear worker safety limit 100 msv):
o Survey 10k people in three high risk towns:
<1msv 58%
<5msv 95%
>15 msv 23 people

This is a survey based on asking people where they were (indoors/outdoors, in which village etc. ) each day of March 2011. Even if those accounts by the people saying where they were are accurate, the survey maker needs to make various assumptions about how much radiation those people encountered in each location. I am not sure if it is possible to make reliable assumptions concerning cloudshine or Iodine levels.

Still, reports on population exposure are as much guesswork as science. Experts from Hirosaki University did their own thyroid tests on evacuees and found exposure levels higher than the government figures.
http://online.wsj.com/article/SB10001424052970203961204577271152728725214.html
My bolding/underlining

December 2011:

http://www3.nhk.or.jp/news/genpatsu-fukushima/20111130/0430_hanmei.html A study by Nagasaki university found that among 170 Nagasaki prefecture citizens, such as medical professionals, who went to Fukushima prefecture after the accident, 55 people, or 32% were detected as having iodine internal contamination in whole body counter tests performed during the first month after the accident. The highest thyroid equivalent dose was 15 mSv. A trend emerges of higher doses being detected among the people who were in Fukushima prefecture during the first week of the accident. As iodine was never detected in the tests performed in June or later among Fukushima citizens, this Nagasaki university study is deemed a valuable document that might be helpful to accurately estimate the doses received by Fukushima prefecture citizens.

March 10, 2012:

Findings by the research team, led by professor Shinji Tokonami from Hirosaki University, showed that 50 of 65 people checked from April 11 to 17 last year had radioactive iodine-131 in their thyroids, with 26 absorbing radiation doses over 10 millisieverts, and five with doses over 50 millisieverts -- the upper limit set by the International Atomic Energy Agency (IAEA).
http://mdn.mainichi.jp/mdnnews/news/20120310p2a00m0na005000c.html

 

[tsutsuji]

http://sciences.blogs.liberation.fr/home/2012/02/fukushima-contamination-chronique-et-p%C3%A9renne-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].

http://www.irsn.fr/FR/expertise/rap.../IRSN_Rapport_Fukushima-1-an-apres_032012.pdf IRSN "Fukushima, one year after: First analysis of the accident and its consequences", 12 March 2012. 189 pages, in French.

Table 6-XI page 113/189 compares their own estimate ("Bally du Bois et al.") of direct sea releases and airborne deposits into the sea with the other available estimates (PBq of Cs-137) :

publication direct release (PBq)      airb. deposit (PBq)        airb. deposit surface (km x km)
a)                            0.94        
b)                            4                         5                     1700 x 1700
c)                            3.5 ± 0.7    less than direct release
d)                          27 (12-41)               0.0076                 50 x  100
e)                                                       0.18                 1500 x 1500
f)                                                        1                       600 x  600
g)                                                       1                     1700 x 1700

a) NERH 2011 (TEPCO) calculation of the leak's flow rate

b) Kawamura et al. (2011) Comparison of modelling (SEAGEARN)/measurements at sea

c) Tsumune et al. (2011) Comparison of modelling (ROMS)/measurements at sea

d) Bailly du Bois et al.(2011) (IRSN) Quantities deducted from measurements at sea and dilution + pX simulation

e) Honda et al. (2011) Comparison of modelling (JCOPE2)/measurements in Japan

f) Morino et al. (2011) Comparison of modelling (CMAQ)/measurements in Japan

g) Yasunari et al. (2011) Comparison of modelling (FLEXPART)/measurements in Japan

 

[tsutsuji]

http://mdn.mainichi.jp/mdnnews/news/20120326p2a00m0na011000c.html "Some 24.4 percent of people who were hospitalized in Fukushima with psychiatric disorders in the wake of the outbreak of the crisis at the crippled Fukushima No. 1 Nuclear Power Plant had done so possibly because of fears of radiation exposure" (survey at 30 hospitals in Fukushima Prefecture for two months from March 12, 2011, and 27 of them responded to the survey)

 

[tsutsuji]

http://www.nikkei.com/news/topic/side/article/g=96958A9C93819490E2E4E2E3818DE2E4E2E1E0E2E3E0E2E2E2E2E2E2;q=9694E2E6E3E3E0E2E3E3E7E3E5E3;p=9694E2E1E2E4E0E2E3E3E4E6E5E5;n=9694E2E1E2E4E0E2E3E3E4E6E5E6;o=9694E2E1E2E4E0E2E3E3E4E6E5E7 Fuji Film Fine Chemical Plant is located in Hirono, 21 km south of Fukushima Daiichi. In the past, they were awarded the Prime Minister prize for environment, but they had to remove all the lawns and trees for decontamination. Outdoor areas were decontaminated by removing 3 cm thick layers of asphalt, and 5 cm thick layers of soil. At the end of January, when a decontamination phase was ended, they had brought outdoor radiation to 0.1 ~ 0.2 microsievert/hour and indoor radiation to 0.1 microsievert/hour or lower. It is a sharp contrast with the areas outside the plant premises where radiations above 0.5 microsievert/hour can be found. Normal production with three shift work resumed in October. They want to appeal to customers by providing data about their decontamination efforts, but the plant is not running at full capacity. "There is no standard saying how much [decontamination must be done] so that it is safe, so we must make efforts on our own". Mr Akita, the manager in charge of decontamination at the Fuji Film Fine Chemical plant is also a member of the Hirono fire brigade. The fact that the town hall administration came back on 1 March 2012 is a good thing, but when one thinks that not only one chemical plant but the whole town must be decontaminated so that the people can feel safe, thinking about the cost and how hard the efforts have to be, "one feels overwhelmed".

 

[Yamanote]

The fact that the town hall administration came back on 1 March 2012 is a good thing, but when one thinks that not only one chemical plant but the whole town must be decontaminated so that the people can feel safe, thinking about the cost and how hard the efforts have to be, "one feels overwhelmed".

Me too. And what to do with the huge amount of radioactive rubble after this so called "decontamination"?

In some cases it might be better to abandon this places and let the decay do the work.

 

[tsutsuji]

The detailed JAEA/MEXT helicopter map, previously only available as an online zoom and drag map application (at http://ramap.jaea.go.jp/map/ ) is now available in downloadable pdf format at http://ramap.jaea.go.jp/map/mapdf/index.html

 

[MadderDoc]

Stohl et al.:
"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"

"Regarding 133 Xe, we find a total release of 15.3 (uncertainty range 12.2–18.3) EBq, which is more than twice as high
as the total release from Chernobyl and likely the largest radioactive noble gas release in history.
<..>For 137 Cs, the inversion results give a total emission of 36.6 (20.1–53.1) PBq, or about 43 % of the estimated Chernobyl emission."
http://www.atmos-chem-phys.net/12/2313/2012/acp-12-2313-2012.pdf

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120407/0830_anzenkiizyun.html A ministry of labour and health study group has prepared a standard for workers working in contaminated areas, such as repairing roads and water pipes. In areas above 5 mSv/year, workers must carry a dosimeter, and their exposure is limited to 50 mSv/year and 100 mSv/5 years. When working on debris higher than 10,000 Bq/kg whole body counter tests must be performed.

http://www.pnas.org/content/early/2012/03/26/1120794109.abstract Buesseler et al. "Fukushima-derived radionuclides in the ocean and biota off Japan" Proceedings of the National Academy of Sciences of the United States of America. 2012 Apr 2. approved February 24, 2012 (received for review December 19, 2011)

 

[nikkkom]

"Regarding 133 Xe, we find a total release of 15.3 (uncertainty range 12.2–18.3) EBq, which is more than twice as high
as the total release from Chernobyl and likely the largest radioactive noble gas release in history."

Has it any practical long-term significance? Xe-133 decays to stable Cs-133 with half-life of 5 days.

 

[clancy688]

There's something interesting in this recent TEPCO publication:

http://www.tepco.co.jp/cc/press/betu12_j/images/120405j0301.pdf

On page 19 you can see a chart depicting water contamination values:

Cs-134: 9.4E1
Cs-137: 1.1E2
?β: 5.0E5

Where're those samples taken from? And what does the last row imply? All other beta emitters? Only 0.04% of all decay processes in that water are caused by Cs?

 

[tsutsuji]

Where're those samples taken from?

Just a clue: try Google's translation tool with the report's title name.

Or another clue: browse Tepco's English language press releases on the same date.

 

[clancy688]

~~~

Press Release (Apr 05,2012)
Report to NISA regarding the event of water or radioactive material leakage from concentrated water storage tank of water desalinations in Fukushima Daiichi Nuclear Power Station

Thanks for the hint...

 

[nikkkom]

Me too. And what to do with the huge amount of radioactive rubble after this so called "decontamination"?

In some cases it might be better to abandon this places and let the decay do the work.

Half-life of Cs-137 is 30 years. How long are you willing to wait?

 

[Yamanote]

Half-life of Cs-137 is 30 years. How long are you willing to wait?

I personally? Not even a second. But radiation won't ask for my opinion.

And that's exactly my issue with nuclear energy.
If it goes wrong, one might have to wait for a long long time. And not every price on Earth must be paid in money.

Surprisingly they are not even able to effectively decontaminate the water from the reactor buildings, so they have to collect and store huge amounts of radioactive water in tanks, waiting for better days. One year after the accident there is still no apparatus available to do this job. I would like to know why?

 

[nikkkom]

I personally? Not even a second. But radiation won't ask for my opinion.

I am confused. You proposed to not bother with decontamination and wait for decay. Now you say something different: that you don't want to wait. So what are you saying?

Surprisingly they are not even able to effectively decontaminate the water from the reactor buildings, so they have to collect and store huge amounts of radioactive water in tanks, waiting for better days. One year after the accident there is still no apparatus available to do this job. I would like to know why?

First, decontamination apparatus seem to be working well enough, in fact.

Second, technology exists to deal with even MUCH worse materials - the water from Fukushima basements is nothing compared to the first stage of nuclear fuel reprocessing. Ask French and/or Brits, they have it running for decades.

 

[clancy688]

Does anyone know where to find numbers for how many square kilometers are polluted with how much Cs-137?

For example (numbers are made up):

300 km²: 3 MBq/m² or higher
600 km²: 1 MBq/m² or higher

I searched for nearly an hour but didn't find anything useful.

 

[MadderDoc]

Does anyone know where to find numbers for how many square kilometers are polluted with how much Cs-137?

For example (numbers are made up):

300 km²: 3 MBq/m² or higher
600 km²: 1 MBq/m² or higher

I searched for nearly an hour but didn't find anything useful.

Perhaps this article
http://www.pnas.org/content/108/49/19530.full.pdf+html
Quote:
"Our estimates show that the area around NPP in Fukushima, secondarily effected areas (Miyagi and Ibaraki prefectures), and other effected areas (Iwate, Yamagata, Tochigi, and Chiba prefectures) had 137 Cs depositions of more than 100,000, 25,000, and 10,000 MBq km−2 , respectively."

 

[clancy688]

Not quite, but thanks.

 

[tsutsuji]

Also [wrong link] page 68/189: Cs-137 as of the summer of 2011

[Areas outside the forbidden zone]

higher than 1000 kBq/m² : 170 km²

600 to 1000 kBq/m² : 150 km²

30 to 600 kBq/m² : 8200 km²

Similar figures for Chernobyl are provided on the same page.

Edit. Sorry for the mistake. The correct link is http://www.irsn.fr/FR/expertise/rap.../IRSN_Rapport_Fukushima-1-an-apres_032012.pdf

The areas above are those outside the forbidden zone. The forbidden zone is 600 km².

 

[clancy688]

Also http://www.irsn.fr/FR/IRSN_Rapport_Fukushima-1-an-apres_032012.pdf page 68/189: Cs-137 as of the summer of 2011

Thanks! That was exactly what I was looking for. On page 67 there's a chart with more accurate values. Your link didn't work for me, if other members have the same problem, use this one instead:

http://sciences.blogs.liberation.fr/files/irsn_rapport_complet-fukushima-1-an-.pdf

Thing is, I wanted to use those numbers to calculate how much Cs-137 ended up on japanese soil. Sadly the chart apparently only covers Fukushima prefecture, but it's a start.


10 - 30 kBq/m²: 14600 km²; 0.146 / 0.292 / 0.438 PBq total (min / mid / max)
30 - 60 kBq/m²: 4775 km²; 0.143 / 0.215 / 0.287 PBq total (min / mid / max)
60 - 100 kBq/m²: 1545 km²; 0.093 / 0.124 / 0.155 PBq total (min / mid / max)
100 - 300 kBq/m²: 1835 km²; 0.184 / 0.368 / 0.552 PBq total (min / mid / max)
300 - 600 kBq/m²: 380 km²: 0.114 / 0.171 / 0.228 PBq total (min / mid / max)
600 - 1000 kBq/m²: 225 km²; 0.135 / 0.180 / 0.225 PBq total (min / mid / max)
1000+ kBq/m²: 400 km²; 0.400 / 1.200 / 2.400 PBq total (1000 kBq/m² / 3000 kBq/m² / 6000 kBq/m²)

Total deposition: 1.215 / 2.550 / 4.285 PBq (min / mid / max)

 

[tsutsuji]

Why not make your own measurement using the helicopter maps and an area measuring software ?

 

[MadderDoc]

Why not make your own measurement using the helicopter maps and an area measuring software ?

Yes indeed. The fourth airborne monitoring maps would seem suitable for the most heavily contaminated areas, while the wider areas of lesser contamination could be judged from from one of the previous monitoring flights:

 

[clancy688]

Why not make your own measurement using the helicopter maps and an area measuring software ?

I had the same idea, but I'm afraid I have absolutely no clue on how to do that...

 

[MadderDoc]

I had the same idea, but I'm afraid I have absolutely no clue on how to do that...

Basically, you let a graphics program count the number of pixels with similar colors, and use the scale of the image to convert the number of pixels into area. It is not an exact science, but better than counting the pixels yourself :-)

Using that method on the source of the image below I get a total coloured area within the circles, of close to 10000 km2, of which

200 km2 red (>3000 kBq/m2
330 km2 yellow (1000-3000 kBq/m2)
330 km2 green (600-1000 kBq/m2)
510 km2 light blue (300-600 kq/m2)
2380 km2 blue (100-300 kBg/m2)
2370 km2 purple (60-100 kBq/m2)
1990 km2 gray (30-60 kBq/m2)
1880 km2 brown (10-30 kBq/m2)

 

[clancy688]

Thanks! Now we're getting closer.


Those areas are larger than in the IRSN paper...

 

[zapperzero]

The bailout fund keeps swelling. Now TEPCO is proposing (or is it demanding?) to receive 1 trillion yen from the J-gov, in exchange for a, quote, controlling stake in the company.

http://online.wsj.com/article/SB10001424052702304811304577369550496643114.html

 

[BC1]

Does anyone here know anything about the levels of I-129 deposition from this event? Or about the ratio of I-131 to I-129 released?

Is I-129 a significant health hazard? I doubt it unless massive amounts were inhaled/consumed.

Thanks in advance to all of you, my nerdly brethren.

 

[r-j]

Scientists in New Zealand are voicing concerns after monitoring the muttonbird population as it travels back from spending the northern summer in Japan. In 2005, scientists attached tracking devices to a portion of the bird population. The New Zealand “muttonbirders” have been concerned ever since the Fukushima plant started leaking radiation last March.

The birds return to New Zealand every November to mate, but Department of Conservation researcher Graeme Taylor says the birds that did return were in a poor condition.

http://enformable.com/2012/05/new-zealand-scientists-concerns-over-most-unusual-event-in-20-years-of-studies/?utm_source=twitterfeed&utm_medium=twitter

 

[tsutsuji]

http://radioactivity.mext.go.jp/ja/contents/6000/5197/24/191_0511.pdf Helicopter maps of Kyūshū and Okinawa.

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120514/1030_nezumi.html 3100 Bq/kg in akanezumi (Japanese field mice) taken in Kawauchi (Fukushima prefecture, 30 km away from plant, 3.11 microsievert/hour external exposure), and 790 Bq/kg in those from Kita-Ibaraki (Ibaraki prefecture, 70 km away from the plant, 0.2 microsievert/hour). The mice were taken in mountains and forests in October and December 2011 by specialists of the Forestry and Forest Products Research Institute (Tsukuba city).

 

[Yamanote]

I am confused. You proposed to not bother with decontamination and wait for decay. Now you say something different: that you don't want to wait. So what are you saying?

As it appears to be quite difficult to collect the radioactive stuff that was distributed over a large area, there is simply no other choice than to wait for support from decay.

First, decontamination apparatus seem to be working well enough, in fact.

Second, technology exists to deal with even MUCH worse materials - the water from Fukushima basements is nothing compared to the first stage of nuclear fuel reprocessing. Ask French and/or Brits, they have it running for decades.

Obviously not, because if the water would be clean, they could simply discharge it into the ocean (what they will have to do at a certain point in time anyway). So either this technology is not available in Fukushima for some reason, or doesn't work at this scale with this large quantities of contaminated water. At my former company we installed 8 tanks with a volume of 2000 m³ each and I can tell you they were already huge...

IMHO they are just entering new territory an many cases. Think about the sludge from the water decontamination apparatus with highly radioactive material. Where to store it? Do they have to cool the vessels? What about corrosion due to salt water? Questions upon questions.

 

[zapperzero]

Think about the sludge from the water decontamination apparatus with highly radioactive material. Where to store it? Do they have to cool the vessels? What about corrosion due to salt water? Questions upon questions.

They are storing it on site in above-ground tanks. The used filters are also stored on site. From the numbers they publish, it appears the water is much cleaner now than when they started. No, the sludge does not need cooling. I don't know about corrosion, but I'd expect they are lining the tank(s?) with some polymer or another.

 

[nikkkom]

Second, technology exists to deal with even MUCH worse materials - the water from Fukushima basements is nothing compared to the first stage of nuclear fuel reprocessing. Ask French and/or Brits, they have it running for decades.

Obviously not, because if the water would be clean, they could simply discharge it into the ocean (what they will have to do at a certain point in time anyway).

I'm interested in facts: with what exactly the "cleaned" water is still contaminated above allowable limits.

I heard one of the hard to remove contaminants is tritium.

If it's the only above-limits contaminant, I'd say "screw it, dump it in the ocean now". Tritium is one of the least-harmless radioisotopes.

So either this technology is not available in Fukushima for some reason, or doesn't work at this scale with this large quantities of contaminated water.

Large quantities can be made smaller by distillation etc.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120524/index.html The World Health organization has published its report. It is based on the assumption that people did not evacuate and it ignores the food regulations.

http://whqlibdoc.who.int/publications/2012/9789241503662_eng.pdf

Page 63:
"In Fukushima prefecture the estimated effective doses are within a dose band of 1−10 mSv, except in two of the example locations where the effective doses are estimated to be within a dose band of 10–50 mSv.

In prefectures neighbouring Fukushima, the estimated effective doses are within a dose band of 0.1−10 mSv, and in all other prefectures the effective doses are estimated to be within a dose band of 0.1−1 mSv"

Page 33: "Measured levels of activity in marketed rice harvested in 2011 were available in August and September 2011 and none of the reported levels was above the limit of detection"

But we know that rice above detection level was harvested in Fukushima prefecture, although it was mostly not sold, or in rare cases recalled from the shops (see https://www.physicsforums.com/showpost.php?p=3757864&postcount=489 ). The contamination of the rice harvest was found in November (beginning with the Oonami district in Fukushima City : https://www.physicsforums.com/showpost.php?p=3623896&postcount=438 ). The reason why the WHO report ignores the rice harvest's contamination could be that it is "based on data available to the panel up to September 2011." (WHO report, p. 63)They don't seem to take the nuclear workers who worked at the plant into account (although their number is 23,000 http://www3.nhk.or.jp/news/genpatsu-fukushima/20120508/index.html ).

 

[SteveElbows]

Here is another press article about the WHO report:

http://www.guardian.co.uk/world/2012/may/24/fukushima-gets-mixed-radiation-report?newsfeed=true

It does seem to me to add weight to the criticisms of the failure to change the evacuation zone in a timely fashion, given the delay of evacuation from certain locations to the north west of the Fukushima plant even when initial contamination estimates suggested hotspots in these areas.

 

[Rive]

A small question.

On the MEXT site there are those reports about "Results of monitoring the environmental radioactivity level of fallout".

Is this 'fallout' means newly released radioactive particles, or 'just' plainly "radioactivity measured in stuff captured high above the ground"?