Japan earthquake - contamination & consequences outside Fukushima NPP

Astronuc

The strontium would more likely be found in the water at the plant or in the sea, or deposited wherever the water took it. Some will still be in the fuel.

The exact state of the fuel is not known, i.e., how much melted, how much is still intact, and how much reacted with the cooling water and seawater.

Strontium has a melting point of 777 °C and boiling point of 1382 °C, and it tends to form oxides, SrO or in water, hydroxides. It is less volatile than Cs, which has a melting point of 28.44 °C and a boiling point of 671 °C. [data taken from www.webelements.com]

The addition of saltwater would have allowed elements like Cs and Sr to form chlorides, and those would be soluble in water.

tsutsuji

I don't think it is the greatest of articles. The use of "false alarm" language concerning the Setagaya bottles is strange. It is not a secret that Edogawa ward was more highly contaminated than other parts of Tokyo. It is shown on radiation maps including the most recent helicopter survey : http://radioactivity.mext.go.jp/ja/1...910_100601.pdf I think the New York Times should have interviewed Edogawa ward officials or whichever administration or private institution is owning the baseball field. Has there been no measurement of radiations in that baseball field since March, apart from the measurement made by the citizen group ? The radiation measured at the baseball field of Rinkai Ballpark No1　- probably a different one: it is difficult to say as the New York Times does not provide the name of the baseball field - on 26-27 June was 0.15 μSv/h 1 m above ground and 0.15 μSv/h again at 5 cm above ground, according to the ward website at http://www.city.edogawa.tokyo.jp/shi...kka/index.html. Has the "patch of dirt just yards from" the unidentified baseball field contamination been reported to ward officials ? How did they react ? Has the place been marked as a no-entry zone ? Why didn't the New York Times journalists go to the place with a dosimeter and take pictures ?

http://www.asahi.com/national/update...110150155.html One of the Setagaya bottles was marked with "Japan Nocturnal Luminescence". There was a factory with that name, which made luminescent paint for ship and airplane instruments, but it was completely destroyed in the 25 May 1945 bombing of Tokyo.

http://sankei.jp.msn.com/affairs/new...2430023-n1.htm It is possible that the bottles had been there since the construction of the house in the 1950s.

http://mainichi.jp/area/tochigi/news...40168000c.html One fourth of the area of Tochigi prefecture is concerned by the national standard that aims to bring radiation below 1 mSV/year. It is the area above 0.23 μSv/h on the helicopter map. The ministry of environment has yet to prepare detailed maps, but it is expected that Nasu, Nasushiobara, Otawara, Yaita, Shioya, Nikko and Kanuma are included. In Nasu the town has set as a priority to clean schools and the streets used by children going to school by the end of this year, with the goal of cleaning each hot spot higher than 0.5 μSv/h. In one place the radiation could not be brought lower than 0.3 μSv/h after surface removal. Then next year public facilities will be cleaned. "We want to build a 2-3 year middle term plan" a town official said.

tsutsuji

Fukushima prefecture:

http://www.youtube.com/watch?v=0nB1-l2hYtI (NHK) and http://www3.nhk.or.jp/news/genpatsu-...iteisagyo.html The first part of a health survey concerning 28000 people of Fukushima prefecture is late (the video shows the form people must fill indicating if they were indoors or outdoors or travelling, hour after hour, each day on 11 March and following days). The results - estimates of each person's radiation exposure - should have been sent to the people in mid-September, but entering the data into computers takes more time than expected. Sometimes people have forgotten to fill data such as the address of the place where they were evacuated to, and checking those missing data takes time. The survey will ultimately concern the whole Fukushima prefecture population.

http://www3.nhk.or.jp/news/genpatsu-...inankuiki.html According to the last update of the roadmap, the revision of the planned evacuation zone, which depends on the completion of step 2, should be done this year, instead of in January as was originally planned. Tepco estimated the radiation released by the Daiichi plant to be 100,000,000 Bq/hour, which is one half of what it was one month ago, and amounts to an increase of 0.2 mSv/year or below at the border of the plant premises.

http://www3.nhk.or.jp/news/genpatsu-...55_zyosen.html Fukushima City is starting on 18 October its plan to bring in two years' time the radiation in the everyday life space to 1 μSv/h or below. It plans to clean public facilities and all 110,000 households. On 18 October, 360 households in the more highly contaminated Onami district will receive cleaning service from companies commissioned by the City: high pressure cleaning of roofs and gutters, earth removal from gardens will be performed. The streets used by children going to school and the woods and hills near people's homes will also be cleaned. The city is commissioning companies to do the work in the more highly contaminated areas and when the work is more dangerous such as on roofs. In other cases the City expects the collaboration of the inhabitants and of volunteer groups. Finding the workforce is one problem. Another problem is finding how to dispose of the generated waste.
Tokyo:

http://sankei.jp.msn.com/affairs/new...2400022-n1.htm Interview of a Tokyo housewife who joined a 5-6 member radiation checking citizen group: "I sacrificed the time I should spend with my family, but as this is for children, I must do it. Two months ago I measured 0.7 μSv/h near my home, and asked the administration to clean as quickly as possible, but I can't have this being done. One feels a difference of degree of commitment".

Yokohama:

http://www.asahi.com/national/update...110140533.html On 14 October, Yokohama city confirmed the presence of strontium in two samples. The sample from Go-Chome area, Okurayama district - deposits in a street side ditch - was measured with 129 Bq/kg of Strontium 89 and Strontium 90 added together and 39,012 Bq/kg of cesium [137 or 134 or both added together is unclear]. The sample from San-Chome area, Shinyokohama district - deposits in a turned off fountain - was measured with 59 Bq/kg of Sr and 31,570 Bq/kg of Cs.

http://www.yomiuri.co.jp/national/ne...OYT1T01201.htm The results from the third sample, taken on the same apartment building rooftop where a private laboratory had previously detected strontium, have not been publicly released because the agreement of the apartment building inhabitants could not be obtained.
Kawasaki (August - September):
http://news.kanaloco.jp/localnews/article/1108230025/ (23 August) Kawasaki city checked the accumulations of leaves in 35 parks in response to the discovery of high levels of radiations in Hirama park. 0.20 μSv/h (above the 0.19 μSv/h national target value) was found in Nakamaruko Ryokudo. All other locations were below the target value. The 0.20 μSv/h measurement was made 5 cm above the leaf accumulation, close to the center. At the border between the leaves and the path where people walk, it was 0.12 μSv/h.

http://news.kanaloco.jp/localnews/article/1108310014/ (31 August) 34 locations in parks were checked again. The measurement at the location where 0.20 μSv/h had previously been found, was 0.16 μSv/h.

http://headlines.yahoo.co.jp/hl?a=20...00028-kana-l14 (8 September) 0.41 μSv/h (above the 0.19 μSv/h national target value) was found 5 cm above accumulated fallen leaves in Sakuragawa park, Kawasaki city announced. The 4 m² area was covered with a sheet and marked as a no entry zone. It is planned to repeat the measurement in the future.

Sorai

Is this measured in I-131 equivalents or just directly cesium releases without any conversion?

Sorry if this has been asked before.

Astronuc

100,000,000 Bq/hour is a measure of decay rate, regardless of the isotope. It should be Ʃλ_iN_i/V, where λ_i is the decay constant of radionuclide i, N_i/V is the concentration of radionuclide i in whatever volume is released - whether air/steam or water.

There should be little I-131 (~8-day half-life) left to release, since this should have decayed away. The longer-lived I-129 would be present, but with low activity. It's possible that Kr-85 would be in steam or air released. In the water would be Cs-134, Cs-137 and Sr-89, Sr-90, along with Ru-103, Ru-106, and perhaps radioisotopes of Se, Sn, Sb are likely in the effluents. Most other remaining isotopes (of Y, Zr, Nb, Ce, Pm, Sm, Eu) should be bound as oxides in the fuel, although some may have leached out. It's also possible that the coolant contains activitated corrosion products from core structural materials. And there may be some transuranics.

It would help if they itemized the nuclides they believe are responsible for the activity.

clancy688

I believe that he wanted know whether this number is the converted I131 activity as used for determining INES classifications or just the actual escaping activity with no conversion whatsoever.

Shinjukusam

Heh, I remember the day the media learned you could do that. Suddenly they got a whole new bunch of big numbers to throw around.

tsutsuji

Tokyo:

http://www3.nhk.or.jp/news/html/2011...350041000.html 3.99 μSv/h was found in an Adachi ward survey on 17 October, 5 cm above ground near a swimming pool equipment room in Higashifuchie primary school. On 18 October afternoon the top 10 cm layer of earth was removed and the radiation dropped to 0.15 μSv/h at 5 cm above ground and 0.12 μSv/h at both 50 cm and 100 cm above ground, which is below the 0.25 μSv/h standard decided by this ward, and the no-entry regulation was lifted in the night. The completion of a survey of the school's side ditches, roofs and places where rainwater gathers is planned for 19 October. In the future, the ward will check the side ditches and draining trenches in 800 locations such as schools and parks one after the other.

http://www.yomiuri.co.jp/e-japan/tok...OYT8T00085.htm Map of the location of the Higashifuchie primary school hot spot (black circle on the map). The 17 October survey was performed in a hurry by the ward after some citizens who had measured 20 locations reported that five of them, including the Higashifuchie school hot spot, were above the 1 μSv/h national standard. While it was confirmed that 1 μSv/h was exceeded at 5 cm above ground at the Higashifuchie school hot spot, at 50 cm and 100 cm above ground the measurements were respectively 0.41 and 0.24 μSv/h. In the other four spots, the ward found radiations between 0.43 and 0.95 μSv/h at 5 cm above ground. Until then the ward had made measurements at 1500 locations where children spend their everyday lives (schoolyards, parks, etc.) and had performed cleaning each time the ward's own standard - set at 0.25 μSv/h - had been exceeded. In the future, the ward will check locations that children don't enter on a daily basis inside schools, kindergartens, nursery schools etc, but where there is a probability of presence of hot spots such as below rainspouts.

http://www.yomiuri.co.jp/politics/ne...OYT1T00963.htm In response to the recent hotspot discoveries in Funabashi (Chiba prefecture) or Adachi ward (Tokyo), the minister of education and science, Masaharu Nakagawa announced in a press conference after the 18 October cabinet meeting that the government will issue a guideline addressing hotspot measurement method and cleaning.

Astronuc

Perhaps, but normally, the iodine may be calculated as does equivalent iodine (DEI) in which case one needs to know the activity of specific isotopes and weight the dose appropriately.

Total activity is simply not enough information.

Sorai

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...s/111017e3.pdf [page 14]

tsutsuji

http://www.yomiuri.co.jp/national/ne...OYT1T00946.htm The nashi pear growers of Tottori prefecture (Western Japan) are requesting a compensation because the nashi pear prices dropped by 30% after nashi pears from Fukushima prefecture were distributed in Kansai and other areas.

http://www3.nhk.or.jp/news/genpatsu-...019/index.html Helicopter monitoring, originally planned in 22 prefectures from Aomori to Aichi, will eventually be performed in the whole country.

http://www3.nhk.or.jp/news/genpatsu-...mujinheri.html Tamura town (former evacuation prepared area) will use a 2.70 m long unmanned helicopter to monitor radiations in field and forest areas.

Hagashimurayama, Tokyo:

http://mainichi.jp/select/jiken/news...40090000c.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".

http://sankei.jp.msn.com/region/news...2200016-n1.htm Hagashimurayama city found radiations higher than 0.19 μSv/h at 13 locations in 6 primary schools and 2 junior highschools. A survey of ditches and rainspouts will be performed in kindergartens and nursery schools in the future.

http://www3.nhk.or.jp/news/html/2011...368281000.html Video of the cleaning of the 2.153 μSv/h hotspot. The radiation dropped to 0.102 μSv/h after earth and sand removal. The second highest hotspot in the 8 schools, after the 2.153 μSv/h one, was a 0.5 μSv/h one.

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."

http://www.city.adachi.tokyo.jp/010/d00400047.html (and http://www.city.adachi.tokyo.jp/010/...tihyo_1019.pdf Map of measurement points). 6 additional locations were checked on 19 October at Higashifuchie school. 3.61 μSv/h was found 5 cm above ground at a rainwater gully near the entrance of the gymnasium (see circled number 24 on the map). After high pressure washing of the gully and installation of a concrete cover, the radiation dropped to below 0.25 μSv/h at 50 cm above ground. A temporary enclosure was set up to prevent people from approaching. The earth clogged inside the gully will be removed tomorrow or later. More details are provided about the other finds and countermeasures.

http://www.yomiuri.co.jp/kyoiku/news...OYT8T00666.htm The number of locations in the Adachi ward where high levels of radiation might be found and which the ward has began to survey and clean is 800. According to a ward official, completing this work "will take a considerable amount of time".　At Sano district learning center, which is one of the five locations checked on 17 October, the radiation was still high with 0.31 μSv/h after cleaning, and the ward is considering asphalt removal.

NUCENG

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/2011...409211000.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/d...600_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...40184000c.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/gun...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/...20-852625.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...5340002-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...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...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/...20-852641.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...9570002-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/tok...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/na...002000115.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/201110...090022000.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

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

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

http://www.asahi.com/national/update...110210504.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):
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.

http://www.youtube.com/watch?v=kjaU1MKnw0I (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".