Japan earthquake - contamination & consequences outside Fukushima NPP

[NUCENG]

Yes, that was my question. But it seems they are just reporting total releases without conversion. Cs-134 and Cs-137, according to the new version of the roadmap: http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/111017e3.pdf [page 14]

If they were reporting the results in terms of dose (Sv or Gray) it would probably be a dose equivalent value. Since they are reporting it simply using Bq it is most likely a raw reading from a counter type of instrument. This measures the total disintegrations in its sensitivity band.

 

[tsutsuji]

Fukushima:
http://www3.nhk.or.jp/news/html/20111021/t10013409211000.html The ministry of education and science publishes the result of a river water and well water survey in 50 locations mostly in the North-West of the plant, which was performed in two phases before and after the tsuyu rains. Although there was a worry that the rains could carry radioactive substances into ground water or rivers, no big radioactivity variation was observed. Strontium was detected in 10 locations, but in low concentrations.

http://radioactivity.mext.go.jp/ja/distribution_map_around_FukushimaNPP/0002/5600_102001.pdf Survey of radioactive substance migrations in rivers and well waters

Miyagi:
http://www.47news.jp/CN/201110/CN2011102001000849.html A measurement of 4 ~ 5 μSv/h under a rainspout in the land of a private house was confirmed by town employees on 18 October in Yamamoto, Miyagi prefecture, 60 km north of the plant. On 20 October the maximum air radiation measured in that town was 0.33 μSv/h.

Kanto Region:
http://www.47news.jp/CN/201110/CN2011101901000762.html Greenpeace surveyed fish and seafood sold in 17 supermarkets in the Kanto area. All results are below the government limit of 500 Bq/kg. The highest radiation was 88 Bq/kg found in wakasagi fish (Hypomesus nipponensis) caught in Ibaraki prefecture and sold in a Saitama supermarket.

Tochigi:
http://mainichi.jp/area/tochigi/news/20111020ddlk09040184000c.html Starting on 19 October with 8 nursery schools, Nasu city (Tochigi prefecture) is carrying out a hotspot removal work in schools, streets used by schoolchildren and public facilities, that will take until March. The radiation behind a nursery school building was reduced from 0.74 to 0.3 μSv/h. Radiations can be reduced by one half by cutting branches of trees. Earth removal is often more effective than high pressure washing.

Gunma:
http://www.yomiuri.co.jp/e-japan/gunma/news/20111021-OYT8T00105.htm The results of a radiation monitoring and cleaning work in 11 schools have been announced by Maebashi city's relevant city council commision. The highest found radiation was 0.561 μSv/h. Cleaning work such as removing mud from side ditches below gutters or removing fallen leaves enabled to bring radiations to about 0.2 μSv/h.

Saitama:
http://www.nikkansports.com/general/news/f-gn-tp0-20111020-852625.html 0.68 μSv/h was found at 5 cm above ground on 20 October in a junior high school in Saitama city, Saitama prefecture. Earth removal will be performed. This will be the first time in a Saitama city school.

http://sankei.jp.msn.com/region/news/111020/stm11102015340002-n1.htm Kawaguchi city, in Saitama prefecture has decided to abandon its self-decided standard of 0.31 μSv/h, which was based on the ICRP's 1.64 mSv/year. Instead it will use the standard defined on 10 October by the ministry of environment, 0.23 μSv/h. About two past measurements showing radiations above the new standard, the city announced that "the surrounding areas are not above the standard, so they do not require cleaning".

http://www.yomiuri.co.jp/kyoiku/news/20111020-OYT8T00785.htm A rainspout, side ditch survey of 7 prefectoral high schools and two prefectoral parks, where relatively high radiation figures had been obtained during a preceding survey in July, was started on 19 October. The results will be announced on 24 October, and available on the Saitama prefecture website.

Chiba:
http://www.yomiuri.co.jp/kyoiku/news/20111018-OYT8T00921.htm Chiba prefecture started on 17 October a new survey of 51 prefectoral schools in the Tokatsu area in response to the new 1 μSv/h target value indicated by the ministry of education. Choosing 5 locations in each schoolyard, measurements will be made at 0.5 and 1 metre above ground. It will take until the end of November. On 17 October, the highest value was 0.36 μSv/h.

http://www.nikkansports.com/general/news/f-gn-tp0-20111020-852641.html 3.2 μSv/h was found in a park in Matsudo, Chiba prefecture. After cleaning it became 0.3 μSv/h. The city will start checking 350 locations for hotspots at the end of this month.

http://sankei.jp.msn.com/region/news/111020/chb11102019570002-n1.htm Funabashi city announced on 20 October that it found 0.40 and 0.31 μSv/h respectively at a nursery school and a park on 19 October. On 13 October 1.55 μSv/h had been found in a park. The city plans to check 965 facilities within this fiscal year.

Tokyo:
http://www.yomiuri.co.jp/e-japan/tokyo23/news/20111021-OYT8T00095.htm : Kastushika ward announced it found a maximum of 0.67 μSv/h at 5 cm above ground in a survey performed on 19 and 20 October at 32 locations in the streets. Arguing that it is not a radiation level "bearing consequences on everyday life" and that it is "afraid of harming the rights and interests" of local inhabitants, the ward does not want to publicly release the locations of the measurements, nor to inform the local inhabitants. That survey was a response to the finding of radiations higher than 2 μSv/h by a citizen group. While the citizen group measured in private lands, the ward measured in the nearby public streets. The citizen group criticises the ward's response as a "neglectful attitude" as regards the ward citizens' safety.

Kanagawa:
http://news.kanaloco.jp/localnews/article/1110200047/ Sagamihara city (Kanagawa prefecture) released on 20 October the results of a survey at all of the city's primary schools. 29 locations in 16 schools were above the 0.23 μSv/h standard. The survey was started on 11 October, focusing on locations such as below rainspouts where there is a probability of presence of hotspots. The two highest measurements at 5 cm above ground were found at two primary schools with 0.62 μSv/h. After Earth removal, the removed Earth is stored in locations children do not have access to. The checking of junior high schools will start on 19 October. That of kindergartens will start on 20 October.

http://news.kanaloco.jp/localnews/article/1110200031/ 0.24 μSv/h was found below a gutter between the gymnasium and the classroom building in a primary school in Atsugi, Kanagawa prefecture. As this is higher than the city's 0.19 μSv/h standard, Earth and fallen leaves were removed, put in a double layer of vinyl bags and stored in a warehouse. As a result of the Earth removal the radiation dropped to 0.09 μSv/h. It was the first time that a higher than standard spot was found since the city started inspecting schools on 14 October.

http://news.kanaloco.jp/localnews/article/1110200039/ In a primary school in Odawara city, it was decided on 20 October to bury the polluted Earth in a 1.3 m deep hole in the schoolyard, using an excavator. A sheet is put at the bottom of the hole, then the vinyl bags with polluted Earth are put on the sheet, then a second sheet is put on the bags, and then the hole is filled with Earth again. When that was finished, the radiation nearby was 0.06 μSv/h which is hardly different from elsewhere in the school. The same will be done at the other school where radiation was found above standard, and also in the four other school that were below the standard.

Nagano:
http://www.chunichi.co.jp/article/nagano/20111020/CK2011102002000115.html Nagano city (Nagano prefecture) made a survey of side ditches and similar locations at 62 schools and parks from 11 October to 18 October. In one place the radiations were 0.36, 0.14, and 0.09 μSv/h at respectively 5, 50 and 100 cm above ground and it was marked as a no entry zone with a temporary enclosure. Cleaning will be performed after receiving instructions from the prefectoral or national administration. The other 61 places were measured between 0.05 and 0.14 μSv/h. 1.7 μSv/h had been found earlier this month in Karuizawa city (same prefecture).

http://www.shinmai.co.jp/news/20111020/KT111019FTI090022000.html As a result of checking 9 locations where rainwater is falling, a 2.80 μSv/h hotspot and a 1,18 μSv/h hotspot were found at Oga Hall, a concert hall in Karuizawa, Nagano prefecture. After removing a 10 cm layer of gravel, washing the mud, and filling with new pebble gravel, the radiation dropped to 0.20 and 0.10 μSv/h.

http://news24.jp/nnn/news8841175.html Video of the cleaning of a 2.2 μSv/h hotspot found on 19 October in a kindergarten in Karuizawa. It is not decided yet how to dispose of the generated waste.

 

[Gary7]

Awesome work, Tsutsuji. Very much appreciated.

 

[tsutsuji]

Thanks.

http://ramap.jaea.go.jp/map/ A website with the most detailed maps, based on the ministry of education and science data.

 

[zapperzero]

Hagashimurayama, Tokyo:

http://mainichi.jp/select/jiken/news/20111020k0000m040090000c.html 2.153 μSv/h have been found in a ditch behind the lunchroom in a primary school in Hagashimurayama, Tokyo metropolis. The city surveyed 22 schools on 18 October and found radiations of 0.19 μSv/h and higher at 8 schools and removed the contaminated mud. The mud was then temporarily buried inside school premises. The city mayor announced that the scope of the radiation surveys "will be extended with maximum efforts".


Adachi ward, Tokyo:

http://www.yomiuri.co.jp/dy/national/T111019004399.htm (English) "Soil to a depth of 10 centimeters in a one-square-meter area around the drainpipe [where 3.99 μSv/h had been found on 17 October] was removed, put in a bag and buried in a hole 1.2 meters deep at a different location at the school."

So very few of these articles clearly say what is done with the rad waste after it is removed. Do you happen to know if there are government-provided instructions for cleanup and/or storage? Any designated dumping grounds?

 

[tsutsuji]

So very few of these articles clearly say what is done with the rad waste after it is removed. Do you happen to know if there are government-provided instructions for cleanup and/or storage? Any designated dumping grounds?

The minister of education had promised a guideline and a telephone hotline a few days ago:

http://www.asahi.com/national/update/1021/TKY201110210504.html The telephone hotline will be open from 24 October to the end of the year (see phone number in the Asahi article). The guideline will be posted on the ministry website. The target value to be used for hotspots is 1 μSv hotter than surroundings at one metre above ground. For example in Shinjuku, as the radiation is 0.056 μSv/h, a hot spot would be a measurement of 1.056 μSv/h or higher. According to the guideline, the reading should be made 30 seconds after starting measurement. If simple measures such as removing mud from side ditches, removing fallen leaves, cutting branches of trees have no effect, further inspection should be made in cooperation with local governments. If necessary, help can be received from the ministry of environment or the cabinet office. The new hotspot guideline applies to all prefectures except Fukushima prefecture.

I don't know if that guideline will say anything about how to dispose of the generated waste.

erratum (as underlined):

http://news.kanaloco.jp/localnews/article/1110200039/ (20 October) In a primary school in Odawara city, it was decided on 20 October to bury the leaf mold in a 1.3 m deep hole in the schoolyard, using an excavator. A sheet is put at the bottom of the hole, then the vinyl bags with leaf mold are put on the sheet, then a second sheet is put on the bags, and then the hole is filled with Earth again. When that was finished, the radiation nearby was 0.06 μSv/h which is hardly different from elsewhere in the school. The same will be done at the other school where radiation was found above standard, and also in the four other school that were below the standard.

One needs to read the earlier news to understand what happened:

http://news.kanaloco.jp/localnews/article/1110190033/ : (19 October) On 19 October, Odawara city announced that 700 Bq/kg (above the 400 Bq/kg limit, Cs134 and Cs137 added together) had been found in leaf mold made at Kuno and Kataura primary schools. In August, the government issued an instruction requiring to stop using leaf mold in schools. The testing was made between 12 September and 6 October in 6 schools. Radiations were found at 4 schools, and at two schools they are above the limit. The volume at Kuno school is 2 m x 2 m x height 0.5 m. At Kataura, it is 3.2 x 1.8 x height 1 m. The leaves are surrounded by concrete plates, but there is no cover. The radiation was measured at both schools and found to be 0.07 μSv/h [near the leaf mold, I guess], which is not different from elsewhere in the school. As a precaution the leaf mold was covered with blue sheets. Leaves are gathered every autumn, left for one year, and then used in the schools' vegetable gardens. In April, the leaf mold from the past year was used. In July the harvested vegetables were served in dishes such as curry at a summer school event and served to 65 people.

(TBS news of 19 October) : The video starts with the Odawara leaf mold, then goes to Higashimurayama, then citizens are shown gathering signatures in Arakawa ward in Tokyo, asking the ward to check hot spots. Arakawa ward is said to be the only ward in Tokyo that decided not to check hot spots. Then the video goes to Ota ward where 1.01 μSv/h was found at 5 cm above ground under a rainspout in a junior high school, then the 3.99 μSv/h (5 cm above ground) hotspot of Adachi ward's Higashifuchie school is shown. Both are evidence that Tokyo's other wards are inspecting hot spots. Arakawa ward was checked at one location by the Tokyo metropolis administration in June, and in 6 locations in August by a university. The ward says that because those measurements show that the radiations are at a secure level, it did not make further measurements. But the TBS journalist heard from an Arakawa ward primary school that 0.97 μSv/h had been found in the school and the school performed the cleaning by itself. When asked why they don't want to check radiations, the ward officials answered : "radiation measurements must be performed by specialists" and "the national government or Tokyo metropolis must set a standard".

 

[rowmag]

Thanks again, tsutsuji. Your efforts are very much appreciated.

As for the method of disposal, our local school just dug a hole around back and buried the offending material there. In the absence of official guidance, there is not much other option.

I worry that such spots are not being durably marked for future decades. Before the meltdowns we already had stories of schools burying time capsules, which are meant to be found, but nobody remembers where they were buried a mere 20 years later. It would be nice if some standard sign (like a radiation sign) were encouraged to be buried with the waste, so that future excavators know what they have encountered.

 

[tsutsuji]

http://mainichi.jp/select/wadai/news/20111022k0000m040072000c.html 57.5 μSv/h was found in Kashiwa, Chiba prefecture, in an empty lot owned by the city and used for free as a public square by the local neighbourhood association, but it is suspected that it is not linked with the Fukushima accident. It was covered with sandbags and blue sheets and marked as a no-entry zone. The ministry of education and science will perform a detailed survey on 24 October.

http://www.tv-asahi.co.jp/ann/news/web/html/211021054.html The 57.5 μSv/h measurement was made 30 cm underground.

TBS video: the yellow sign on the Kashiwa hotspot reads 4.5 μSv/h at 1 m above ground and 7.6 μSv/h at 50 cm above ground. On the surface it was 20 μSv/h. Then they dug and found that the radiation increased. According to the city, because the radiation is higher underground than on the surface, it is difficult to think that this could be related to the Fukushima accident.

http://radioactivity.mext.go.jp/ja/important_imformation/0006/index.html The new hotspot guideline's main web page. (The full guideline is at http://radioactivity.mext.go.jp/ja/important_imformation/0006/111021Radiation_measurement_guideline.pdf ) (21 October 2011) (It applies to all prefectures except Fukushima prefecture)

http://www.meti.go.jp/press/2011/07/20110715009/20110715009.html "basic thoughts as regards decontamination in the everyday life space in Fukushima prefecture" (15 July 2011). It includes http://www.meti.go.jp/press/2011/07/20110715009/20110715009-2.pdf , which contains a few indications about the temporary storage of generated waste, mostly referring to http://www.env.go.jp/jishin/attach/fukushima_hoshin110623.pdf "Guideline about the treatment of disaster waste in Fukushima prefecture" (23 June 2011). For example at the bottom, on page 13, the distances between temporary waste storage facilities and inhabited areas are recommended : waste with 8,000 ~ 20,000 Bq/kg of Cs134 and Cs137 added together should be at least 6 m away from inhabited areas. With 100,000 Bq/kg or above, the waste should be at least 70 m away from inhabited areas.

 

[zapperzero]

Thanks again, tsutsuji. Your efforts are very much appreciated.

As for the method of disposal, our local school just dug a hole around back and buried the offending material there. In the absence of official guidance, there is not much other option.

I worry that such spots are not being durably marked for future decades. Before the meltdowns we already had stories of schools burying time capsules, which are meant to be found, but nobody remembers where they were buried a mere 20 years later. It would be nice if some standard sign (like a radiation sign) were encouraged to be buried with the waste, so that future excavators know what they have encountered.

There are GPS receivers. Someone could surely mark the spot on a map? Perhaps a concerned citizen could put a placemark on google Earth or something?

 

[tsutsuji]

Tokyo:
http://mainichi.jp/select/science/news/20111022k0000m040141000c.html Shinjuku ward (Tokyo) announced that the presence of a 25 g bottle, filled to one third (that should make 8 g) of uranyl sulfate, covered with a lead sheet, in the science preparation room of a junior high school, was reported by a former teacher. The radiation around the bottle was 0.14 ~0.17 μSv/h. The former teacher remembered about this when the radium was found in Setagaya. The possession of uranyl sulfate should have been notified to the authorities as is required by law. According to the former teacher, the manufacturer refused to take the bottle back ten years ago when the school requested it to do so, so it stayed at school.

http://sankei.jp.msn.com/region/news/111021/tky11102122360008-n1.htm 1.247 μSv/h, 0.858 μSv/h and 0.319 μSv/h were found in 3 of the 6 schools that were checked in Higashikurume city, Tokyo metropolis. Monitoring and, if needed, cleaning will be performed in all of the city's 21 schools.

Kanagawa:
http://sankei.jp.msn.com/region/news/111021/kng11102122190005-n1.htm 0.75 μSv/h, 0.77 μSv/h, and 0.83 μSv/h were found 1 cm above ground at three schools in Yokohama's Totsuka ward. All three are above Yokohama city's 0.59 μSv/h standard. After cleaning 0.08 μSv/h, 0.06 μSv/h and 0.30 μSv/h were measured. 20 locations in 18 schools in 9 of Yokohama's wards were found to be above the standard so far, as 80% of Yokohama's schools have already been checked. Checking the remaining schools will take until the end of this month.

http://sankei.jp.msn.com/region/news/111021/kng11102122220006-n1.htm Yokohama's resources and environment agency has started checking facilities which are accessed by the public on occasions such as study tours. 0.81 μSv/h (above Yokohama city's 0.59 μSv/h standard) was found 1 cm above ground near a warehouse, close to the local sport field, in the premises of a refuse collection office. As the warehouse contains baseball equipment, it was possible that children might have approached the hot spot.

http://www.yomiuri.co.jp/e-japan/kanagawa/news/20111021-OYT8T01341.htm Dried shiitake mushrooms grown in Sagamihara city have been found above the 500 Bq/kg limit. Sales are stopped.

Saitama:

http://www.nikkansports.com/general/news/f-gn-tp0-20111020-852625.html 0.68 μSv/h was found at 5 cm above ground on 20 October in a junior high school in Saitama city, Saitama prefecture. Earth removal will be performed. This will be the first time in a Saitama city school.

http://www.yomiuri.co.jp/kyoiku/news/20111021-OYT8T00647.htm On 14 October, 0.60 μSv/h had been found at the bottom of a Japanese zelkova (elm-like tree) in a park in Saitama city and the city had decided... to do nothing saying that it does not bear consequences on health. As a result of the discrepancy between the measures taken in the park and in the junior high school, the City announced that a uniform guideline would be provided between November 1 and November 10. The city's 164 schools and kindergartens will be checked.

http://mainichi.jp/area/saitama/news/20111020ddlk11040280000c.html 97 brands of tea, out of a total of 1081 brands tested, were found above the 500 Bq/kg limit, Saitama prefecture announced on 19 October.

Ibaraki:
(TBS) 1040 Bq/kg was found in kuritake mushrooms grown in Kanuma city. All thirteen kuritake farmers of Kanuma are stopping the sales. The farmer where the 1040 Bq/kg sample was found had already sold 26 kg on the local market.

http://www.yomiuri.co.jp/e-japan/tochigi/news/20111017-OYT8T01458.htm (17 October) 29600 Bq/kg (above the 400 Bq/kg limit) was found in leaf mold used by students to grow seedlings at an agriculture and forestry high school in Kanuma. 70 bags (the volume of one bag is 40 litre) were bought in June and July. 22 bags were not used. The radiation near the seedlings was 0.05 ~ 0.10 μSv/h. Above unused bags, it was 1 μSv/h. The leaf mold has been used for 3 months by 150 students.

http://www.tokyo-np.co.jp/article/ibaraki/20111022/CK2011102202000065.html Kujikawa river (which flows in Fukushima and Ibaraki prefectures) is a famous fishing spot for ayu. The number of tourists and anglers has dropped by one half. The radiation in ayu was found to be 88 Bq/kg (below the 500 Bq/kg limit).

Tochigi:
http://www.yomiuri.co.jp/e-japan/tochigi/news/20111020-OYT8T01349.htm Nameko mushrooms grown in Nasushiobara city were found with 619 Bq/kg (above the 500 Bq/kg limit). Sales are stopped.

 

[zapperzero]

Tokyo:
http://mainichi.jp/select/science/news/20111022k0000m040141000c.html Shinjuku ward (Tokyo) announced that the presence of a 25 g bottle, filled to one third (that should make 8 g) of uranyl sulfate, covered with a lead sheet, in the science preparation room of a junior high school, was reported by a former teacher. The radiation around the bottle was 0.14 ~0.17 μSv/h. The former teacher remembered about this when the radium was found in Setagaya. The possession of uranyl sulfate should have been notified to the authorities as is required by law. According to the former teacher, the manufacturer refused to take the bottle back ten years ago when the school requested it to do so, so it stayed at school.

http://sankei.jp.msn.com/region/news/111021/tky11102122360008-n1.htm 1.247 μSv/h, 0.858 μSv/h and 0.319 μSv/h were found in 3 of the 6 schools that were checked in Higashikurume city, Tokyo metropolis. Monitoring and, if needed, cleaning will be performed in all of the city's 21 schools.

Kanagawa:
http://sankei.jp.msn.com/region/news/111021/kng11102122190005-n1.htm 0.75 μSv/h, 0.77 μSv/h, and 0.83 μSv/h were found 1 cm above ground at three schools in Yokohama's Totsuka ward. All three are above Yokohama city's 0.59 μSv/h standard. After cleaning 0.08 μSv/h, 0.06 μSv/h and 0.30 μSv/h were measured. 20 locations in 18 schools in 9 of Yokohama's wards were found to be above the standard so far, as 80% of Yokohama's schools have already been checked. Checking the remaining schools will take until the end of this month.

http://sankei.jp.msn.com/region/news/111021/kng11102122220006-n1.htm Yokohama's resources and environment agency has started checking facilities which are accessed by the public on occasions such as study tours. 0.81 μSv/h (above Yokohama city's 0.59 μSv/h standard) was found 1 cm above ground near a warehouse, close to the local sport field, in the premises of a refuse collection office. As the warehouse contains baseball equipment, it was possible that children might have approached the hot spot.

http://www.yomiuri.co.jp/e-japan/kanagawa/news/20111021-OYT8T01341.htm Dried shiitake mushrooms grown in Sagamihara city have been found above the 500 Bq/kg limit. Sales are stopped.

Saitama:


http://www.yomiuri.co.jp/kyoiku/news/20111021-OYT8T00647.htm On 14 October, 0.60 μSv/h had been found at the bottom of a Japanese zelkova (elm-like tree) in a park in Saitama city and the city had decided... to do nothing saying that it does not bear consequences on health. As a result of the discrepancy between the measures taken in the park and in the junior high school, the City announced that a uniform guideline would be provided between November 1 and November 10. The city's 164 schools and kindergartens will be checked.

http://mainichi.jp/area/saitama/news/20111020ddlk11040280000c.html 97 brands of tea, out of a total of 1081 brands tested, were found above the 500 Bq/kg limit, Saitama prefecture announced on 19 October.

Ibaraki:
(TBS) 1040 Bq/kg was found in kuritake mushrooms grown in Kanuma city. All thirteen kuritake farmers of Kanuma are stopping the sales. The farmer where the 1040 Bq/kg sample was found had already sold 26 kg on the local market.

http://www.yomiuri.co.jp/e-japan/tochigi/news/20111017-OYT8T01458.htm (17 October) 29600 Bq/kg (above the 400 Bq/kg limit) was found in leaf mold used by students to grow seedlings at an agriculture and forestry high school in Kanuma. 70 bags (the volume of one bag is 40 litre) were bought in June and July. 22 bags were not used. The radiation near the seedlings was 0.05 ~ 0.10 μSv/h. Above unused bags, it was 1 μSv/h. The leaf mold has been used for 3 months by 150 students.

http://www.tokyo-np.co.jp/article/ibaraki/20111022/CK2011102202000065.html Kujikawa river (which flows in Fukushima and Ibaraki prefectures) is a famous fishing spot for ayu. The number of tourists and anglers has dropped by one half. The radiation in ayu was found to be 88 Bq/kg (below the 500 Bq/kg limit).

Tochigi:
http://www.yomiuri.co.jp/e-japan/tochigi/news/20111020-OYT8T01349.htm Nameko mushrooms grown in Nasushiobara city were found with 619 Bq/kg (above the 500 Bq/kg limit). Sales are stopped.

Perhaps it would be better if sale and consumption of mushrooms were to be banned altogether in the affected areas?

 

[tsutsuji]

Tokyo:
http://www.tokyo-np.co.jp/article/tokyo/20111022/CK2011102202000045.html A citizen group reported 15 measurements on streets used by the schoolchildren of 3 schools in the eastern part of Adachi ward. One measurement was above the 1 μSv/h level set by the ward for immediate response. The ward employees made their own measurement: 1.39 μSv/h and after cleaning it was 0.24 μSv/h. The ward is carrying out a plan to check 800 facilities. The measures for streets will be decided later. In case a high radiation were reported concerning a national or a private road, the report would be passed to the relevant administration or owner.

Chiba:
http://www.tokyo-np.co.jp/article/chiba/20111022/CK2011102202000055.html Four cities of the more highly contaminated Tokatsu area (the North-Western part of Chiba prefecture) have announced the results of accumulated dose measurements in schools. They used surveymeters with a dose integrating function for a given period during the second term (which started in September) and calculated a yearly estimate. While most schools in Kashiwa had results between 0.5 and 0.8 mSv/year, two were found to be above the 1 mSv/year standard set by the ministry of education. The highest value was 1.561 mSv/year. There are some differences with the measurement methods used in each city. While in Kashiwa the surveymeters were left at school during the nights, in Abiko, the teachers carried the surveymeters at home (thus measuring the radiations inside their homes during the nights). In Nagareyama the surveymeters were measuring only between school opening and closing times and the yearly estimate is calculated on the basis of the number of school days in the year (about 200). Other cities such as Matsudo are planning to release the results of similar surveys.

http://www.47news.jp/CN/201110/CN2011102201000718.html An Earth sample from Kashiwa's Nedo district hotspot (the 57.5 μSv/h hotspot) was analysed, and its radiation was found to be 276,000 Bq/kg of cesium. According to the ministry of education and science, judging from the proportions of Cs 134 and Cs 137, "it is not possible to rule out the possibility that it was released by the Fukushima Daiichi nuclear plant accident". However, judging from the distance from the plant and the fact that the radiation is higher underground than on the surface "that's a lot of strange things". The ministry will conduct an investigation on the site on 24 October.

http://www.asahi.com/national/update/1022/TKY201110220424.html Three samples from Kashiwa's 57.5 μSv/h hotspot were analysed. Two samples taken at a 30 cm depth had 276,000 and 192,000 Bq/kg of cesium. The sample from the surface had 155,300 Bq/kg of cesium.

http://www3.nhk.or.jp/news/html/20111022/t10013443691000.html A sample taken at a 30 cm depth had 124,000 Bq/kg of Cs-134 and 152,000 Bq/kg of Cs-137. Added together, this is 276,000 Bq/kg. Radioactive substances other than cesium were not found. According to Osaka university associate professor Mamoru Fujiwara, Cs-134 has a 2 year long half life and is produced in nuclear plants so it is possible to think that it was released by Fukushima Daiichi. By analysing the soil, it might be possible to know if it is Kashiwa soil (where cesium became more concentrated in a similar phenomenon as in side ditches) or Fukushima soil from an area close to the plant that was brought to Kashiwa.

http://mainichi.jp/select/jiken/news/20111023k0000m040060000c.html Dr. Osamu Amano of JAEA suspects that the reason why the radiation is higher underground than on the surface might be that the contaminated soil was buried there by people after removing it from somewhere else.

Fukushima, Miyagi, Ibaraki, Tochigi:
http://www3.nhk.or.jp/news/genpatsu-fukushima/20111022/1720_senryo.html 22 October air dose rates between 8:00 and 9:00 AM: Fukushima City: 0.93 μSv/h , Koriyama: 0.86 μSv/h, Minamisoma: 0.41 μSv/h, Iwaki: 0.17 μSv/h, Sendai: 0.059 μSv/h, Kitaibaraki: 0.153. Utsunomiya: "not above usual level".

Tochigi:
http://www.pref.tochigi.lg.jp/kinkyu/houshasen.html Air dose rates at 50 cm above ground on 22 October: 0.10 μSv/h in Utsunomiya, 0.31 μSv/h in Nasu, and 0.18 μSv/h in Nikko.

I was wondering why the NHK said "not above usual level" for Utsunomiya. I guess that the reason is that they use the 20 m high monitoring post value: 0.053 μSv/h : (http://www.pref.tochigi.lg.jp/kinkyu/houshasen.html) . Similarly, as shown on http://radioactivity.mext.go.jp/en/monitoring_by_prefecture_environmental_radioactivity_level_prefecture/2011/10/18459/index.html (second table), the 1 m surveymeter value for Fukushima city is 30% or 40% higher than that of the 2.5 m high monitoring post.

Miyagi:
http://www.r-info-miyagi.jp/r-info/ This is Miyagi prefecture's official google-map-based radiation website, displaying the latest data. Most of the locations are shown with blue squares (lower than 0.3 μSv/h). However a few green squares with radiations between 0.3 and 0.5 μSv/h are present in the South in the areas neighbouring Fukushima prefecture. In Sendai, Wakabayashi ward, the darkest blue square for Sendai, we have the following graph : http://www.r-info-miyagi.jp/r-info/radiation/space_graph.php?pm=1&id=234&p=1&ln=ja (move mouse to display the values) with 0.13 and 0.12 μSv/h at respectively 50 cm and 1 m above ground on 20 October. This is nearly twice the value announced by NHK for the same day for Sendai: 0.057 μSv/h (http://www3.nhk.or.jp/news/genpatsu-fukushima/20111020/1725_houshasenryo.html) (based probably on a measurement made at a different location and/or height).

 

[rowmag]

There are GPS receivers. Someone could surely mark the spot on a map? Perhaps a concerned citizen could put a placemark on google Earth or something?

Sounds complicated. I think a more reliable method would be to distribute a bunch of plastic discs with the radiation sign stamped on them to all towns, who could then distribute them to schools, PTAs, jichikais, regular private citizens, etc., with instructions to toss it in the hole on top of the waste before filling the hole back in. Perhaps write a date and survey number on it with magic marker.

Maybe even embed an RFID tag in the plastic disc to make it easier to "prospect" for later?

 

[tsutsuji]

http://mainichi.jp/life/food/news/20111022k0000m040085000c.html About the revision of the provisional food radiation safety regulations, Minister of health and labour Yoko Komiyama said in a 21 October press conference: "I think it is necessary to secure food safety even more than now. I think it is going to be more severe". The provisional food radiation safety regulations will be revised by the end of this year. On 31 October the Food safety commission will provide a report addressing the following issues: 1) whether the 5 mSv/year maximum that is the base of the present regulation is valid, 2) whether to keep the present food categories ("vegetables", "drinks" etc.), and 3) whether to introduce a special regulation for young children.

http://ipsnews.net/news.asp?idnews=105289 (29 September) "New Radiation Limits Demanded for Children"

http://mainichi.jp/select/wadai/news/20111024k0000m040065000c.html The ministry of education and science investigated Kashiwa's Nedo district hotspot (the 57.5 μSv hotspot) on 23 October. A human cause, such as people dumping contaminated Earth from somewhere else, has been ruled out. There is a strong possibility that contaminated rainwater leaked from the side ditch and accumulated in the earth. The 30 cm deep, 30 cm wide concrete side ditch is broken over a 0.5 ~ 1 m length. After removing the blue sheet, the ministry found a maximum of 14.6 μSv, and 2 μSv at 1 m above ground. In the surroundings of the blue sheet it was 0.6 μSv [height above ground is unclear].

 

[tsutsuji]

Hokkaido:
http://www.hokkaido-np.co.jp/news/donai/327512.html 7.55 μSv/hour was found in a second hand car in Otaru port in a shipment destined for Korsakov, Sakhalin.

Fukushima:
http://mainichi.jp/area/fukushima/news/20111025ddlk07040144000c.html A volunteer group from Hiroshima has started decontaminating a 6.6 ton ship that had been carried by the tsunami wave and had landed 3 km inland near national road No. 6 in Minamisoma. The radiation was 0.2 ~ 0.5 μSv/hour. The decontamination was done with high pressure washing. The resulting waste water and trash was put in drums. The ship will be carried back to the sea using a crane on 26 October.

http://ajw.asahi.com/article/0311disaster/fukushima/AJ2011102515713 (English) In Minamisoma, "Radioactive cesium-137 was detected at below 10 becquerels per kilogram of a student's weight in 199 students. The substance was also found at from 10 to less than 20 becquerels in 65 students; 20 to less than 30 becquerels in three students; and 30 to below 35 becquerels in one student, the hospital said."

Tochigi:
http://mainichi.jp/area/tochigi/news/20111024ddlk09040057000c.html On 23 October, 10 local inhabitants prevented 5 trucks loaded with radioactive ashes to enter the "wider area clean center" in Otahara (which treats the waste of both Otahara and Nasu). They want Nasu city to share the burden.

http://mytown.asahi.com/tochigi/news.php?k_id=09000001110250003 While the problem of the final disposal of radioactive ashes is unsolved, 60 tons of fallen leaves and cut branches are remaining in a park in Otahara. They were measured with 5830 Bq/kg on 4 October, 1761 Bq/kg on 18 October. In the surroundings the radiation is between 0.4 and 0.5 μSv/hour.

Ibaraki:
http://www.nikkansports.com/general/news/f-gn-tp0-20111025-854553.html 10 locations are higher than 1 μSv/hour near a regulating reservoir receiving a neighborhood's rainwaters in Tsuchiura. The highest is 3.13 μSv/hour (1 m above ground).

http://ibarakinews.jp/news/news.php?f_jun=13194645342578 picture of "no entry" traffic cone at a Tsuchiura hotspot.

Chiba:
http://www.asahi.com/national/update/1024/TKY201110240601.html In reponse to the 57.5 μSv/hour hotspot finding, Kashiwa city has decided that the following would be done until the end of November: 1) to measure and publicly release measurement data of all public facilities (1350 locations, 4,057,231 m²), 2) to measure in private lands upon owners' requests, 3) to lend surveymeters.

http://www.yomiuri.co.jp/kyoiku/news/20111025-OYT8T00459.htm It was learned that two of Abiko city's primary schools had had hotspots higher than 10 μSv/hour. According to Abiko city's board of education, one hotspot found in a primary school was measured on 15 September with 11.3 μSv/hour on the surface and 1.7 μSv/hour at 50 cm above ground. A sample was measured with 67,680 Bq/kg of Cs. Earth removal was conducted "until the last decade of October", bringing the radiation to 0.6 μSv/hour at 50 cm above ground. The removed Earth was taken to the "clean center". In another school, mud that was extracted from the swimming pool was measured in June with 10.1 μSv/hour on the surface and 3.56 μSv/hour at 1 m above ground. It was covered with a sheet and a layer of Earth and surrounded with a no-entry rope.

TBS video showing the former 11.3 μSv/hour hot spot in an Abiko primary school. After Earth removal, 0.5 μSv/hour is remaining and the area is surrounded by a no-entry rope.

http://www.tokyo-np.co.jp/article/chiba/20111025/CK2011102502000043.html Chiba City has started checking the 14 housing estates it manages. 9 locations were checked in one of them after receiving information from inhabitants. The highest spot was 1.72 μSv/hour at 5 cm above ground. The values at 50 cm above ground were between 0.11 and 0.57 μSv/hour.

http://www.tokyo-np.co.jp/article/chiba/20111025/CK2011102502000044.html Nagareyama city has disclosed its plan to check schools etc. for hotspots and bring radiations down to a 0.3 μSv/hour or below standard (5 cm above ground).

http://ajw.asahi.com/article/0311disaster/life_and_death/AJ2011102515690 (English) "Radioactive ash from incinerator nearing limit" in Nagareyama

Saitama:
http://www.yomiuri.co.jp/kyoiku/news/20111025-OYT8T00446.htm 3.659 μSv/hour (1 cm above ground) was found in a high school in Yashio. In 3 high schools in Misato and Yoshikawa, spots between 1.42 and 2.017 μSv/hour (1 cm above ground) were also found. School employees removed the mud, put it in vinyl bags and buried it inside the schools, bringing radiations to 0.269 ~ 0.6 μSv/hour.

http://mainichi.jp/area/saitama/news/20111025ddlk11040221000c.html 5 locations were found above the 0.6 μSv/hour local standard in Kawagoe. The highest is 2.05 μSv/hour in a rainwater gully in a community center.

Tokyo:
http://mainichi.jp/area/tokyo/news/20111025ddlk13040244000c.html Until now, Hachioji city was inspecting 12 locations in parks once a week and finding about 0.1 μSv/hour. In response to the hotspot finding in Higashimurayama city, Hachioji city will start inspecting 368 locations including schools in November. A citizen group member found 0.38 μSv/hour in a park and sent a sample to a laboratory which found 8434 Bq/kg of Cs and 179 Bq/kg of I-131 [it is not clear exactly when].

http://www.tokyo-np.co.jp/article/tokyo/20111025/CK2011102502000013.html Tokyo's Ota ward found spots above 0.23 μSv/hour in a primary school and a kindergarten. It is considering asphalt removal in two places as radiation could not be brought lower than 0.56 μSv/hour after cleaning (0.80 μSv/hour before cleaning) in one place and 0.46 μSv/hour [how much before cleaning is unclear] in the other place.

http://ajw.asahi.com/article/0311disaster/fukushima/AJ2011102315550 (English) "Retail outlet displays radiation levels of produce"

Kanagawa:
http://news.kanaloco.jp/localnews/article/1110250039/ A radiation of 58 μSv/hour was found in a second hand car ready for export in Kawasaki port. Kawasaki port has inspected 40,454 second hand cars since August. Among them, 7 were above the 5 μSv/hour limit.

Kanto:
http://ajw.asahi.com/article/0311disaster/fukushima/AJ2011102415591 (English) "Expert: Radioactive materials reached Kanto via 2 routes"

Shizuoka:
http://www.shinmai.co.jp/news/20111025/KT111024FTI090011000.html 1.16 and 1.13 μSv/hour were found in two locations in Karuizawa high school.

Mie:
http://mytown.asahi.com/mie/news.php?k_id=25000001110250001 A pork factory in Tsu city started 100% testing on 26 September. Testing pork for radiations is rare anywhere in Japan. An employee approaches a measuring instrument near the meat and reads 0.03 ~ 0.04 μSv/hour. On the data sheet, similar figures are written. Interview of a consumer, a mother of a 7 year old boy. She buys vegetables because she had the radiation near her home tested by a company and the result was "no problem". She avoids buying fish. As school lunches or presents cannot be avoided, "her heart feels pain". The prefecture's 29 August ~ 24 October beef tests are all below the 500 Bq limit. But the prefecture does not publicly release the data saying exactly how much. "Thinking that there might be hundreds of Bq per kg, it is a worry". The price of Mie prefecture grown rice has risen from last year by ¥ 2500 to ¥ 15,500 for 60 kg. There is a tendency to buy one year old rice at higher prices. Fish sales are stable. The peak fishing season for migratory fish coming from the Tohoku region such as katsuo (skipjack tuna) is November. The Mie fishing industry is keeping an eye on the radiation results from Kanagawa prefecture catches, as the sanma (pacific saury) are just swimming South alongside the Tohoku coast in mid-October.

Osaka:
http://ajw.asahi.com/article/0311disaster/fukushima/AJ2011102415666 (English) "The vehicle's radiation level tested at 110 microsieverts per hour, far exceeding the government limit for export containers of 5 microsieverts per hour."

 

[tokyo_dom]

Thanks as always for the super informative updates. I find myself coming to this thread first for updates on the radiation effects...

Oh and..

http://ajw.asahi.com/article/0311disaster/fukushima/AJ2011102315550 (English) "Retail outlet displays radiation levels of produce"

I have just found my new favourite supermarket.

 

[tsutsuji]

Yamagata:
http://mainichi.jp/area/yamagata/news/20111027ddlk06010157000c.html Yamagata city announced on 26 October the results of a hotspot survey in 42 schools, kindergartens and nursery schools. 1.27 μSv/hour was found in the western side ditch of Kanai junior high school's gymnasium. It was decontaminated in compliance with the "Guideline for decontamination performed by cities, towns and villages" [ I guess it is http://www.meti.go.jp/press/2011/08/20110826001/20110826001-6.pdf , issued by the Nuclear Emergency Response Headquarters and dated 26 August]: 200 litres of sand and Earth were removed and put into eleven 20 litre waterproof bags. The bags were put in a hole dug on the land on the North side of the gymnasium, covered with a waterproof sheet, and a 30 cm layer of earth. The temporary disposal inside school premises results from the fact that the national government has not taken a decision concerning disposal sites. After Earth removal the side ditch's radiation declined to 0.20 μSv/hour and the radiation on the hole after filling up was the same as before with 0.12 μSv/hour. The radiations at both locations will be periodically measured in the future. Yamagata city started on 7 October its plan to check the radiations of sport fields, side ditches, rainwater gullies, fallen leaf heaps, flowerbeds, plantings, sandboxes, and bottoms of rainspouts at 161 schools, kindergartens, nursery schools, etc. The results for the 42 places checked until 24 October were released. Sport fields: 0.11 ~ 0.18 μSv/hour. Side ditches except Kanai junior high: 0.10 ~ 0.33 μSv/hour. Rainwater gullies, fallen leaf heaps, flowerbeds, plantings, and sandboxes: 0.08 ~ 0.26 μSv/hour. Bottoms of rainspouts: 0.11 ~ 0.76 μSv/hour.

Iwate:
http://www.iwate-np.co.jp/cgi-bin/topnews.cgi?20111021_6 Ichinoseki city checked 138 primary, junior high, nursery schools and kindergartens and found radiations above the ministry of education's 1 μSv/hour standard in 92 of them, totalling 489 spots. 3 junior high schools and one nursery school had radiations above 10 μSv/hour. The hotspots were found in locations where rainwater accumulates such as side ditches except for yet another nursery school where 1.28 μSv/hour was found in the schoolyard or in the garden. All hotspots have been designated as no entry zones and 19 have been cleaned.

Fukushima:
http://www.kfb.co.jp/news/index.cgi?n=201110271 A radiation survey was performed on 18 October in home gardens and in front of house entrances in the Ikenodai district of Koriyama city. The results at 1 m above ground are between 0.53 and 3 μSv/hour. At 50 cm above ground, between 0.46 and 3.3 μSv/hour. The 3 μSv/hour measurement at 1 m above ground matches the target value for the establishment of "specific evacuation recommendation spots", but Koriyama's mayor said "It is on a lawn and if [earth] removal is performed, the radiation will decline" and the local nuclear emergency response headquarters said "we respect the city's thought".

http://mainichi.jp/area/fukushima/news/20111027ddlk07040210000c.html Whether Ikenodai will be established as a specific evacuation recommentation spot is under study. The detailed Ikenodai survey was done as a result of the 20 July ~ 13 August monitoring car survey performed in Koriyama which had found results between 0.13 and 2.81 μSv/hour. As high values had been found in Ikenodai, the places above 2.5 μSv/hour were the object of a detailed residential area survey.

http://news24.jp/nnn/news8652578.html (with video) FCT (Fukushima Central Television) measured 80 μSv/hour in a location close to Koriyama station. A station employee found 120 μSv/hour with his own surveymeter. In that place, the Earth's color is different. Koriyama city is dispatching its employees for a detailed investigation.

Tochigi:
http://www.tokyo-np.co.jp/article/tochigi/20111027/CK2011102702000072.html?ref=rank Nikko city has released a radiation map. The highest location is Kobyaku bridge with 0.74 μSv/hour. One measurement was made at 50 cm above ground in each 1 km square cell [map: http://www.city.nikko.lg.jp/kankyou/gyousei/jishin/documents/rdmap.pdf and data: http://www.city.nikko.lg.jp/kankyou/gyousei/jishin/documents/sokuteikasho.pdf].

http://www.shimotsuke.co.jp/news/tochigi/top/news/20111026/645041 Nikko city's map is based on 538 measurements. 90% of the city is 0.40 μSv/hour or below.

Ibaraki:
http://ibarakinews.jp/news/news.php?f_jun=13196046468234 Ishioka city has created a "radiation response room" staffed with 4 people. 6 surveymeters will available next month for the citizens to borrow. The city has decided to buy a food radiation measuring system and will start checking school meals in January. The city measured 1164 air radiations in 162 facilities. At 1 m above ground, none was found above 1 μSv/hour. On the surface 86 locations in 36 facilities were above 1 μSv/hour. 4.407 μSv/hour in a preschool children center decreased to 0.244 μSv/hour after cleaning, and 2.56 μSv/hour declined to 0.59 μSv/hour after cleaning in a primary school.

Chiba:
http://mainichi.jp/area/chiba/news/20111023ddlk12040070000c.html On 19 October, 2.74 μSv/hour was found on leaves at the bottom of a keyaki tree (Japanese zelkova) in an apartment estate in Shiroi. The city asked the appartment estate to decontaminate. At 50 cm above ground it was 0.35 μSv/hour. 2.14 μSv/hour was still found on 20 October after the leaves had been arranged a little. On 21 October leaves and Earth were removed and a no entry traffic cone was set. An official in another city of North-Western Chiba prefecture said that they can't afford to decontaminate in private lands. The chairman of Shiroi's appartment estate said "as it was only one location, we could afford it. Had it been a wide area, it would have been difficult".

http://www.tokyo-np.co.jp/article/chiba/20111023/CK2011102302000035.html Kamagaya's board of education checked the streets used by children going to school. The maximum found was 0.21 μSv/hour (below the 0.26 μSv/hour standard). The measurement was made between 25 August and 26 September on 600 locations along 90 km of streets, with a measurement every 100 or 200 m at the height of a child's chest (between 1 and 1.2 m). 320 measurements were shown on a map. The measurements will be repeated at the 108 locations where the highest values were found. [http://www.city.kamagaya.chiba.jp/news/gakkoukyouiku/h231021tsuugakuro_houshasen_map/h231021tsuugakuro_houshasen_map.html We received complaints that the children street radiation map was too hard to read... so please wait until we prepare another map ].

http://www.chibanippo.co.jp/cn/news/local/62804 On 24 and 25 October, during the "Kashiwa shock" (the finding of the 57.5 μSv/hour hotspot in Kashiwa) the neighbouring Narareyama city's radiation telephone hotline received respectively 35 and 67 phone calls instead of the usual 5 to 20 calls per day.

http://sankei.jp.msn.com/region/news/111026/chb11102621550006-n1.htm Funabashi city found 0.45 μSv/hour near a swimming pool, 0.42 μSv/hour near a regulating reservoir, 0.33 μSv/hour in a junior high school, and 0.39 μSv/hour at another swimming pool. These are above the 0.3 μSv/hour local standard.

Tokyo:
http://mainichi.jp/area/tokyo/news/20111027ddlk13040238000c.html Ota ward has started checking its 287 schools and kindergartens, especially in places easily approached by children such as playground equipments. Cleaning will be performed whenever 0.25 μSv/hour or above is found at 5 cm above ground. About 5 locations are to be measured in each school. 1.01 μSv/hour was found in September below a rainwater pipe in a school. 22 schools were checked on 25 October, and 0.31, 0.33, 0.27 and 0.28 μSv/hour hotspots were cleaned in 4 schools.

http://www.tokyo-np.co.jp/article/tokyo/20111027/CK2011102702000038.html As the helicopter survey had shown relatively higher radiations in the mountain part of Tokyo metropolis, 79 locations were measured in Okutama, Hinorara, and part of Ome. The results are 0.04 ~ 0.13 μSv/hour, with 0.13 μSv/hour being found at the top of Sayaguchiyama mountain. Measurements were made at a 1 m height above asphalt, concrete, or earth, as the radiations would become higher if measured on fallen leaves.

(TBS) Setagaya ward has started checking 258 parks. The highest figure found yesterday was 0.11 μSv/hour in Matsugaoka park.

Kanagawa:
http://www.tokyo-np.co.jp/article/kanagawa/20111027/CK2011102702000046.html Yokohama city has announced that it will use the ministry of environment's 0.23 μSv/hour limit at 1 m above ground. However, Yokohama city's self-decided standard of 0.59 μSv/hour at 1 cm above ground remains unchanged. In neighbouring Kawasaki city, a more severe standard of 0.19 μSv/hour at 5 cm above ground is used. In answer to the suggestion that Yokohama should use the same standard as Kawasaki, a Yokohama official said "the national government's standard is also easy to understand from a scientific point of view".

http://news.kanaloco.jp/localnews/article/1110270005/ Yokohama's 0.59 μSv/hour standard was calculated for a maximum of 1 mSv/year on the basis of 210 school days per year, 8 hours per day. The ministry of environment's 0.23 μSv/hour was calculated by adding 0.04 μSv/hour (natural ground radiation) to a 1 mSv/year maximum (365 days per year, 8 hours outdoors, 16 hours indoors). The maximum measurements of 2800 locations where radiations can concentrate such as roof side ditches in Yokohama's about 900 primary and junior high schools have been 0.21 μSv/hour at 1 m above ground, and 0.98 μSv/hour at 1 cm above ground so far.

http://mainichi.jp/area/kanagawa/news/20111027ddlk14040305000c.html 0.75 μSv/hour was found in a primary school side ditch in Yokosuka. In response to this finding, Yokosuka has decided to check all schools and to use the same standard as Yokohama (0.59 μSv/hour). The contaminated Earth will be removed, put in a double layer of vinyl bags and buried under 50 cm of Earth in the school premises.

http://news.kanaloco.jp/localnews/article/1110270019/ 0.22 ~ 0.29　μSv/hour (above the 0.19 μSv/hour standard) were found in side ditches in the same school that had problem with leaf mold in Odawara. In Isehara city, a maximum of 0.99 μSv/hour was found in deposits in roof side ditches in 4 schools.

http://news.kanaloco.jp/localnews/article/1110260017/ Atsugi city checked 9 parks and all results are below the 0.19 μSv/hour standard.

Niigata:
http://www.niigata-nippo.co.jp/news/pref/28520.html As part of a survey of schools in 7 cities or towns, Murakami city checked rainwater concentrating spots in 16 locations and the highest figure was 0.13 μSv/hour.

Nagano:
Erratum: Karuizawa is in Nagano prefecture (not Shizuoka):

http://www.shinmai.co.jp/news/20111025/KT111024FTI090011000.html 1.16 and 1.13 μSv/hour were found in two locations in Karuizawa high school.

http://www.shinmai.co.jp/news/20111024/KT111021FTI090043000.html Chikuma city checked its 13 schools and found a maximum of 0.47 μSv/hour.

 

[zapperzero]

http://www.nature.com/news/2011/111025/full/478435a.html#B1

Nature discusses the Stohl paper.

What if TEPCO and the J-gov really got the accident sequence and the source term wrong? Does this have consequences for the cleanup?

 

[tsutsuji]

Fukushima:
http://news24.jp/nnn/news8652582.html (with video) At the 80 μSv/hour hotspot close to Koriyama station, city employees put the Earth in watertight vinyl bags and buried it on the same location, bringing the radiation down to 2 ~ 3 μSv/hour. The city employees are futher investigating the detailed radiation cause in those surroundings.

http://www.asahi.com/national/update/1029/TKY201110290361.html Minister Goshi Hosono disclosed a roadmap concerning the middle term storage of contaminated Earth in Fukushima prefecture, so that the middle term storage facility (facilities?) should become available in January 2015. Within 30 years after the opening of the middle term facility (facilities?), the long term facility (facilities?) will become available outside Fukushima prefecture. The location of the middle term faciliy (facilities?) will be chosen in 2012 fiscal year. Its construction should start in 2014 fiscal year.

Tokyo:
http://www.asahi.com/national/update/1029/TKY201110290519.html A 170 μSv/hour hotspot was found in Itchome, Hachiman'yama district, Setagaya ward close to a supermaket. On 29 October, the ministry of education and science said "There is a high probability that there is something below the asphalt" and plans to further investigate by digging on 31 October.

TBS video of the 170 μSv/hour Setagaya hotspot. The ministry of education and science said that the probability that this hotspot is related to the Fukushima NPP accident is low.

 

[clancy688]

Those Fukushima-unrelated hotspots give me the shivers. The japanese are only discovering those spots because they're looking for ones created by the accident.
How many 100+ uSv/h hotspots are there in other countries? For example the US or Europe? I don't think that there'll be people patrolling the streets with geiger counters, so those things will stay undiscovered...
Reminds me of that accident in Taiwan where radioactive steel was molten down an used to built an apartment complex.

Edit: New http://www.irsn.fr/FR/Actualites_presse/Actualites/Documents/IRSN-NI-Impact_accident_Fukushima_sur_milieu_marin_26102011.pdf" ).

They guess that 27 PBq C137 escaped to the sea between March and July. But that's all I can decipher. I don't speak a single word french.

 

[tsutsuji]

Ibaraki:
http://ibarakinews.jp/news/news.php?f_jun=13197218597112 Tsukuba city bought a ￥　5,000,000 measuring tool, able to measure 30 Bq and above of Cs 134, Cs 137 and Iodine, and started checking school meals on 27 October. Results are shown on the city's website.
http://mainichi.jp/area/ibaraki/news/20111028ddlk08040166000c.html The detection threshold is 30 Bq for a 10 minute test. The school meals for all of the city's primary, middle and kindergarten schools are prepared in 6 cooking centers. 2 centers and one of the 23 nursery schools will be checked every day with samples of the ingredients of the food that will be served on the next day.
[PLAIN]http://www.city.tsukuba.ibaraki.jp/dbps_data/_material_/_files/000/000/009/517/kennsa.JPG
Tsukuba city's Hitachi - Aloka medical measuring tool for school lunch testing(from http://www.city.tsukuba.ibaraki.jp/53/009517.html )

http://www.city.tsukuba.ibaraki.jp/dbps_data/_material_/_files/000/000/009/517/111028.pdf The latest results (27 and 28 October: everything is marked with 検出せず meaning not detected)

 

[clancy688]

Another interesting thing regarding this IRSN paper:

According to user in a German Fukushima-related board, IRSN concluded that the Sr/Cs-ratio in the ocean was 1-20% of the Cs activity, while it was only 0.1% on land.

 

[zapperzero]

But that's all I can decipher. I don't speak a single word french.

Translated summary follows:

High radioactive contamination of the marine environment has occurred as a result of the accident which happened at Fukushima Dai-ichi NPP on March 11 2011. The sources of contaminants are the dumping of contaminated water directly into the sea, which has continued until around April 8 and, to a lesser degree, fallout from airborne releases (which took place between March 12 and 22).

In the immediate environs of the NPP, concentrations in seawater have reached several tens of thousands of Bq/L for Cs-134 and Cs-137 and even surpassed 100 000 Bq/L for Iodine 131. I-131 concentrations have diminished rapidly on account of it having a short half-life and it has become undetectable in mid-May. Concentrations of Cs-134 and Cs-137 in the immediate area started decreasing on April 11 and, since mid-July, they have decreased beyond the limit of the detector used (5 Bq/L).

By interpreting the results of Cs-137 concentration measurements, IRSN has updated the estimate of the total Cs-137 release which took place from March 21 to mid-July. The value thus obtained is 27x10E+15, most of it (82 %) having been dumped before April 8.

This radioactive release into the sea represents the biggest point release of artificial nuclides into the marine environment ever.

At the same time, the site layout allowed radionuclides to disperse in an exceptional fashion, as one of the globe's most important marine currents has moved the contaminated water towards the open Pacific. Thus, measurements taken in seawater and coastal sediment beds let us assume that consequences in terms of radioprotection will become small for pelagic species starting Autumn 2011 (small concentrations in seawater and limited storage into sediment).

Meanwhile, significant pollution of littoral seawater in the immediate environs of the NPP may persist for a longer time, because of ongoing transport of contamination by wave action on contaminated soil.

Moreover, some littoral areas, not yet identified, could present dilution or sedimentation characteristics which are less favorable than those being observed at the present time.

Finally, the possibility of the presence of other persistent nuclides such as Strontium 90 or Plutonium has not been sufficiently characterized with measurements.

Recent measurements point towards lingering contamination of marine species (fish, mostly) which are being caught along the Fukushima coastline. Benthic and filter-feeding organisms, as well as the fishes at the top of the food chain are, for now, the most susceptible to Cesium pollution. This constitutes sufficient justification for continued monitoring of marine species taken from Fukushima coastal waters.

 

[westfield]

Those Fukushima-unrelated hotspots give me the shivers. The japanese are only discovering those spots because they're looking for ones created by the accident.
How many 100+ uSv/h hotspots are there in other countries? For example the US or Europe? I don't think that there'll be people patrolling the streets with geiger counters, so those things will stay undiscovered...

snip .

Yes, if someone like google had geiger counters on their streetview cars it might reveal some interesting data.

 

[tsutsuji]

http://www.fnn-news.com/news/headlines/articles/CONN00210584.html & http://www.yomiuri.co.jp/national/news/20111031-OYT1T00553.htm At the Setagaya Hachiman'yama district supermarket, the excavation work will start on 1 November. A ward official said the "excavation work, etc. " should be completed in one or two weeks' time. On 31 October afternoon, protective sheets are laid out for dust release prevention. According to ward officials, there are only two radiation sources: the 170 μSv/hour pavement and the other location where 110 μSv/hour was found. The nature of the radioactive substances is still unknown.

 

[zapperzero]

http://www.fnn-news.com/news/headlines/articles/CONN00210584.html & http://www.yomiuri.co.jp/national/news/20111031-OYT1T00553.htm At the Setagaya Hachiman'yama district supermarket, the excavation work will start on 1 November. A ward official said the "excavation work, etc. " should be completed in one or two weeks' time. On 31 October afternoon, protective sheets are laid out for dust release prevention. According to ward officials, there are only two radiation sources: the 170 μSv/hour pavement and the other location where 110 μSv/hour was found. The nature of the radioactive substances is still unknown.

Aum Shinrikyo had a center in Setagaya for a long time. They were stockpiling deadly bacteria and chemicals... why not some radioactive materials for a dirty bomb too? It would make sense to keep the stuff in many small stashes, no?

http://www.japantimes.co.jp/text/nn20020619b6.html

 

[tsutsuji]

Tokyo:
http://mainichi.jp/select/jiken/news/20111030ddm041040132000c.html [Setagaya] Until the supermarket was started in 1999, there was a parking lot. As written on the commemorative stone, in 1955 ~ 1973 there was a junior college training students into agricultural managers. Until 1986 there was a facility belonging to an organization involved in the training of foreigners into agricultural managers. A 66 year old graduate says "it was not supposed to have anything to do with radioactivity". An employee of the organization said "we did not use radioactive substances".

http://www.tamapre.jp/news/2011/10/28/microspot-in-tama.html A 0.44 μSv/h (5 cm above ground), 0.17 μSv/h (50 cm above ground) 0.12 μSv/h (1 m above ground) μSv/h hotspot was found, made no-entry, on 27 October in a school in Tama city.

Kanagawa:
http://news.kanaloco.jp/localnews/article/1110310014/ Sagamihara city announced on 31 October that 13 spots higher than 0.23 μSv/h, the highest one being 0.63 μSv/h (5 cm above ground), were found and cleaned in 7 schools.

Fukushima:
http://www.yomiuri.co.jp/kyoiku/news/20111028-OYT8T00810.htm As a result of the lifting of the evacuation-prepared zone, the 229 students of Minamisoma's agricultural high school are leaving their temporary school buildings in Soma, and going back to their old school in Minamisoma. As a result of the cleaning work which has been performed since August, radiations inside classrooms were brought to 0.12 ~ 0.18 μSv/h. Measurements will be performed twice a day in places such as classrooms and schoolyards. Outdoor club activities will be practised with long sleeves, trousers and masks. Agriculture practice will be restricted to practice inside greenhouses or vinyl houses. During the parent-teacher conference, parents asked "What are the countermeasures against aftershocks or tsunamis?" or "are you going to ask the students to remove grass or fallen leaves, on which radioactive substances can easily adhere ?", but there was no voice against the move.

 

[tsutsuji]

Tokyo:
http://www.asahi.com/national/update/1101/TKY201111010480.html [Setagaya] The ministry of education and science said there was a high probability that the source is radium 226. The characteristic radiation of radium was detected.

http://mainichi.jp/select/science/news/20111102k0000m040026000c.html An open bottle with a 40 mSv/h radiation was found at a 40 cm depth below the 110 μSv/h Setagaya hotspot.

Fukushima:
http://www3.nhk.or.jp/news/genpatsu-fukushima/20111101/index.html The ministry of education and science released tellurium and silver maps. Where the concentration is the highest, tellurium accounts for 0.03% of Cs-137 and silver for 0.16% of Cs-137.

http://radioactivity.mext.go.jp/ja/distribution_map_around_FukushimaNPP/0002/5600_103120.pdf Tellurium and silver maps

http://www.yomiuri.co.jp/national/news/20111101-OYT1T01107.htm Fukushima City released the results for 3 of the 6 private homes where decontamination efforts were carried out starting on 18 October in the Onami district (radiation before and after cleaning in μSv/h at 1 cm above ground) :

Gravel yard: 　3 to 0.7 (-76.7%)
In front of house entrance: 2.7 to 0.7 (-74.1%)
Tilled roof: 1.4 to 1.1 (-21.4%)
Asphalt yard: 1.8 to 1.4 (-22.2% "only")

 

[Bodge]

Fukushima:
http://www3.nhk.or.jp/news/genpatsu-fukushima/20111101/index.html The ministry of education and science released tellurium and silver maps. Where the concentration is the highest, tellurium accounts for 0.03% of Cs-137 and silver for 0.16% of Cs-137.

http://radioactivity.mext.go.jp/ja/distribution_map_around_FukushimaNPP/0002/5600_103120.pdf Tellurium and silver maps

Where has the Silver come from?

Neutron capture by silver-109 from the reactors?

Is silver in the control rods?

 

[Bodge]

The science ministry is saying that the 40 millisievert source is buried radium-226.

Why would someone keep burying this around Setagaya?

I imagine it is expensive stuff?

 

[Astronuc]

Where has the Silver come from?

Neutron capture by silver-109 from the reactors?

Is silver in the control rods?

Silver is a fission product. Silver is used in PWR control rods in Silver (Ag) - Indium (In) - Cadmium (Cd) or AIC control rod. BWRs typical use B4C and possibly Hf, depending on the control blade design, and the neutron absorbers are cladding in high purity (and low Co) 304 stainless steel.

 

[Marita]

The science ministry is saying that the 40 millisievert source is buried radium-226.

Why would someone keep burying this around Setagaya?

I imagine it is expensive stuff?

Just a guess but during WW2 there was a lot of "Cottage Industry" in Japan , maybe there were some Radium Dial painting going on in those areas and the "Vials" were just lost at the end of the war and wound up buried where they are found today. But I think if they were leftovers from the war they would have pretty much decayed to lower levels by now.

I don't think the war remains is very likely but I also don't think there is some deranged Radium Vial planter going about hiding them in random locations either. It would be nice to see some information on the history of the locations where there were found. Japan has enough to contend with without these "hot spots" popping up randomly.

 

[Shinjukusam]

But I think if they were leftovers from the war they would have pretty much decayed to lower levels by now.

Well, the half-life of R226 is 1601 years; the war wasn't that long ago.

 

[zapperzero]

It would be nice to see some information on the history of the locations where there were found. Japan has enough to contend with without these "hot spots" popping up randomly.

Setagaya-ku is where Aum Shinrikyo was based for some years. I can't think of anything else.

 

[Shinjukusam]

Setagaya-ku is where Aum Shinrikyo was based for some years. I can't think of anything else.

Well, it's also the most populated (1st or 2nd) of the 23 wards of Tokyo, so there is a whole lot that took place there. I don't think it would be related to Aum, they tended to go for much quicker acting methods...