Fukushima Japan earthquake - contamination & consequences outside Fukushima NPP

[tsutsuji]

http://sankei.jp.msn.com/region/news/111011/szk11101118100003-n1.htm Dried shiitake mushrooms with 599 Bq/kg (above the 500 Bq/kg limit) have been found in Izu (Shizuoka prefecture). As a consequence all Izu shiitake sales are stopped. Some people propose to resume sales with a test on every box (20 kg), but nothing has been decided yet.

 

[tsutsuji]

http://mainichi.jp/select/today/news/20111012k0000e040065000c.html As the results of the final tests in Nihonmatsu and Miharu became known on 12 October, all the rice grown in Fukushima prefecture has been found to be below the 500 Bq/kg limit and is allowed for distribution. Rice growing had been forbidden in the three zones (the restricted zone, the planned evacuation zone and the evacuation prepared zone) .

http://new-fukushima.jp/result.php?kind_detail%5B%5D=%E7%B1%B3%28%E6%9C%AC%E8%AA%BF%E6%9F%BB%29&kind_detail%5B%5D=%E7%B1%B3%28%E4%BA%88%E5%82%99%E8%AA%BF%E6%9F%BB%29&start_year=2011&start_month=8&end_year=2011&end_month=10&search_area=&hyoji=all&x=28&y=24 The detailed rice tests results.

http://mainichi.jp/select/weathernews/news/20111012dde041040016000c.html The Yokohama City municipality is carrying out strontium tests in 3 locations in Kohoku ward. From March to May strontium had been found in Fukushima prefecture: 250 Bq/kg in Namie (29 km away from the plant), 120 Bq/kg in Iitate (36 km away), and 7.7 Bq/kg in Fukushima City (62 km away).

 

[joewein]

Near an elementary school in Tsurumaki, Setagaya-ku, Tokyo as much as 3.35 uSv/h have been measured, according to http://www3.nhk.or.jp/news/html/20111013/t10013231511000.html" for a report.

It was also observed that the reading was higher off the ground than at ground level, which is kind of consistent with the failure of the steam cleaning to significantly reduce radiation. A test by experts then showed that the radiation comes off the side of adjacent properties, such as fences and walls (if my Japanese is good enough), with an even higher reading of 3.35 uSv. Both the original reading and the latest reading are higher than at the village headquarter at Iitate mura in Fukushima prefecture.

I also live in Setagaya, about 2.5 km from that location.

 

[joewein]

The news from Tsurumaki, Setagaya took a surreal twist when the city announced that the unusually high radioactivity measured out in the street was emanating from a bottle kept inside a cardboard box in a house at that street.

No explanation was given for why that bottle was there, what exactly it contained and how come it was kept in that home, except that the radiation was not related to the Fukushima accident.

See: http://www3.nhk.or.jp/news/html/20111013/t10013243881000.html"

 

[swl]

Some good news about the triple meltdown. Had there been no accident in Fukushima, that radiation source in Setagaya might have gone undetected for years or decades.

 

[joewein]

There was a playground across the street from that house and a kindergarden and a pre-school for toddlers (hoikuen) nearby, as well as an elementary school.

It's the house at the corner of the intersection, surrounded by trees, in the middle of this map:

http://g.co/maps/fx9uc

The bottle was in a cardboard box inside a wooden box under the floor of the house, which was uninhabited.

 

[tsutsuji]

http://mainichi.jp/select/wadai/news/20111014k0000m040083000c.html The dimensions of one glass bottle is diameter 5 cm x height 7 cm, and there are 3 or 4 thin and high glass bottles. The 30 μSv/h upper limit of the measuring instrument was exceeded. The owner says "it is the first time I see those [bottles]". The radiation in the area dropped to 0.1 to 0.3 μSv [per hour, I guess] after the ministry of education and science employees put the bottles in a lead containment.

http://mainichi.jp/select/wadai/news/20111014k0000m040083000c2.html The Funabashi City municipality (Chiba prefecture) announced on 13 October that 0.91 μSv/h was found in a location in a park where a citizen group had found 5.82 μSv/h on 12 October. At a ceramic-made grass burning equipment it was 1.40 μSv/h. The spots have been designated as no entry zones and surface removal has been undertaken. 1.40 μSv/h is the highest record so far in that city. The municipality "does not want to treat lightly" the measurement difference with the citizen group, which is higher than the normal variation that is observed in one day's time.

http://radioactivity.mext.go.jp/ja/1910/2011/10/17485.pdf Niigata and Akita helicopter survey results.
http://radioactivity.mext.go.jp/ja/5000/2011/10/5000_1013.pdf Aichi helicopter survey plan.

TBS video news about Setagaya, made before discovering the bottles. About the helicopter surveys, it is explained that helicopters display mean values, and are not able to detect small hot spots. Then there is a report about a junior high school in Ota ward, where 1.01 μSv/h was found. 13 among 37 schools in Ota ward were found with "high levels" of radiations. Then there is a report about the 1.40 μSv/h spot in Funabashi. Then it is about the schools and kindergartens in Karuizawa, Nagano prefecture, where a survey found results between 0.05 and 1.7 μSv/h. Then the video goes back to Setagaya with a university professor detecting radium-226 with a 90% probability with his measuring instrument, and suspecting the radiation is not Fukushima-related.

 

[Bodge]

"in Funabashi, city workers cordoned off an area near a children’s theme park when a citizens’ group detected a level there of 5.82 microsieverts per hour"

http://www.washingtonpost.com/world...around-tokyo/2011/10/13/gIQA6XqHhL_story.html

Maybe there are radioactive bottles buried everywhere

 

[tsutsuji]

http://new-fukushima.jp/result.php?kind_detail%5B%5D=%E3%82%B7%E3%83%AD%E3%83%A1%E3%83%90%E3%83%AB&start_year=2011&start_month=8&end_year=2011&end_month=10&search_area=&hyoji=all&x=25&y=15 In Iwaki, Fukushima prefecture, shiromebaru fish (Sebastes cheni) caught on on 8 September was found with 1200 Bq/kg of Cs-137 and the one caught on 5 October had 420 Bq/kg.

http://www.asahi.com/national/update/1014/TKY201110130770.html Picture of the Setagaya bottles. The picture caption reads "tens of bottles where radioactive radium 226 was found. Some of them are filled with powder".

Another TBS video saying that radium was detected from the Setagaya bottles and that the ministry of education and science believes for this reason that this event is not related to Fukushima Daiichi. The video contains no precise explanation about the contents of the blue box that is carried from the house to the car.

http://mainichi.jp/area/tokyo/news/20111012ddlk13040260000c.html 208 measurements were made from 6 to 11 October 5 cm above ground below rain gutters near flowerbeds in 25 primary schools, 12 junior high schools, 5 kindergartens and 1 nursery in Ota ward, Tokyo. 30 measurements at 13 of these schools are above the 0.25 μSv/h limit.

 

[zapperzero]

http://new-fukushima.jp/result.php?kind_detail%5B%5D=%E3%82%B7%E3%83%AD%E3%83%A1%E3%83%90%E3%83%AB&start_year=2011&start_month=8&end_year=2011&end_month=10&search_area=&hyoji=all&x=25&y=15 In Iwaki, Fukushima prefecture, shiromebaru fish (Sebastes cheni) caught on on 8 September was found with 1200 Bq/kg of Cs-137 and the one caught on 5 October had 420 Bq/kg.

That's... a lot. Are these fish bottom-feeders?

 

[tsutsuji]

http://www.yomiuri.co.jp/national/news/20111013-OYT1T01038.htm The radiation on the top of the Setagaya bottles was 600 μSv/h. At the bottom of a tree, 8.40 μSv/h. On the wall of the building, 18.6 μSv/h.

That's... a lot. Are these fish bottom-feeders?

http://ja.wikipedia.org/wiki/メバル Unlike kasago (Sebastiscus marmoratus) it does not stay on the bottom but also swims in shoals around reef. Sometimes they are also treading water and hovering along vertical rock walls.

 

[joewein]

"in Funabashi, city workers cordoned off an area near a children’s theme park when a citizens’ group detected a level there of 5.82 microsieverts per hour"

http://www.washingtonpost.com/world...around-tokyo/2011/10/13/gIQA6XqHhL_story.html

Maybe there are radioactive bottles buried everywhere

Maybe not:

False alarm in Funabashi

Staff report

Measurements by a citizens' group of high radiation at a park in Funabashi, Chiba Prefecture, proved to be incorrect, the city said Thursday.

The group reported readings of 5.82, 2.1 and 1.79 microsieverts per hour at three locations in Anderson Park, but the city measured 0.91, 1.40 and 0.79 microsierverts per hour at the same spots Thursday. (http://search.japantimes.co.jp/cgi-bin/nn20111014a1.html" )

 

[tsutsuji]

I think the Japan Times article is biased. 1.4 μSv/h is still high compared to the 0.25 μSv/h standard for schools. And as mentioned in the Mainichi article I mentioned above, the action of the citizen group was followed by the municipality cleaning the hot spots, so it was useful. Also, the Mainichi article gives me the impression that the municipality is trying to have a trusting relationship with the citizen group, so I don't believe that the municipality attacked the citizen group by saying that the citizen group's measurement is "incorrect" or "false". [sorry if this belongs to the "more political thread"].

 

[joewein]

1.4 μSv/h is still high compared to the 0.25 μSv/h standard for schools.

It is indeed, but also not entirely surprising if it was an incinerator for grass, since grass already tends to collect fallout and incinerating organic matter would concentrate the dose.

On the 5.82 vs. 0.91 microsieverts per hour, it's a large difference and it's to their credit that the city is not just brushing it off as a measuring error on behalf of its citizens.

BTW, I ordered a Ukrainian-made dosimeter on eBay yesterday to start collecting radiation data around where I live. While Setagaya and most of Tokyo generally has fairly low levels, I have also been hiking in the remote mountains of Okutama recently, which according to the helicopter maps are the more highly affected parts of the Tokyo Metropolitan area, along with the eastern parts bordering on Northern Chiba.

 

[Jim Lagerfeld]

http://ja.wikipedia.org/wiki/メバル Unlike kasago (Sebastiscus marmoratus) it does not stay on the bottom but also swims in shoals around reef. Sometimes they are also treading water and hovering along vertical rock walls.

Interesting. So far, the worst contamination in fish has mostly been from sandlance, skate and flounder. All bottom dwelling, and eating filter feeders like small shrimp, crab, worm. Mebaru are but are much more predatory.

BTW, I ordered a Ukrainian-made dos...ted to hear how you get on with your counter!

 

[Bodge]

I just got some results from some soil I collected. Total cesium soil from open areas ranged from a couple of hundred bq/kg in my garden in Nakano to a couple of thousand in a Nagareyama playground.

I also collected some material from nearby drains, which ranged from about a thousand bq/kg in Nakano to over ten thousand bq/kg in Nagareyama.

I'd be interested to hear how you get on with your counter!

Where any other isotopes tested for?

"where's there's cesium there's strontium" AFAIK

 

[tsutsuji]

http://www.tokyo-np.co.jp/article/tokyo/20111014/CK2011101402000023.html Every Tokyo ward is responding to the insecurity feeling aroused by the Setagaya events. Suginami ward, which answered to 65 enquiries until 4 PM, is planning to perform additional measurements in children centers and parks, beyond the more than 500 locations already tested. Toshima ward answered to 14 enquiries, and will go on with the weekly testing at the same locations as before in primary and nursery schools. The maximum so far was 0.21 μSv/h. Chiyoda ward has started planning a survey of the paths used by children on their way to school. Koto ward received a few enquiries, but not as many as when highly contaminated Earth was found in Kameido in May. Ota ward has set at 0.25 μSv/h the value above which the ward would start its own survey. Locations such as flowerbeds close to rainspouts with high radiations have been marked as no entry zones in 13 Ota ward schools. In Kita ward, 1.01 μSv/h was found behind a sport warehouse and the surroundings were made a no-entry zone, while Earth removal is under study. 5 additional measurements will be made outside the schoolyards of schools, nursery schools and kindergartens. Citizen groups in Katsushika ward will explain their findings, including 8 locations above 3 μSv/h and 56 locations above 1 μSv/h, to ward officials on 18 October. Theses measurements were made mostly at private facilities which have not been surveyed by the ward so far.

 

[swl]

I just got some results from some soil I collected. Total cesium soil from open areas ranged from a couple of hundred bq/kg in my garden in Nakano to a couple of thousand in a Nagareyama playground.*

I also collected some material from nearby drains, which ranged from about a thousand bq/kg in Nakano to over ten thousand bq/kg in Nagareyama.

*I would be very interested in knowing how you tested your soil samples to determine Bq/kg along with the specific isotopes.

I have found shrubs at Soka Koen measuring as high as 0.8 uSv/h and a roof at our local bunka center that has dirt pooled in a low spot that measures 0.75 uSv/h.*
The soil in our garden (in Soka,
Saitama) dropped from 0.2 to 0.15 uSv/h after tilling, but we still have piles of grass and leaves that are as high as 0.4 uSv/h. I'm particularly interested in knowing the isotopes and Bq/kg of the park and bunka center contamination as I'm reluctant to report it to them just to have them laugh at my Ukranian GM counter.*

 

[tsutsuji]

TBS video of the 1.01 μSv/h find in Kita ward.

http://mainichi.jp/select/jiken/news/20111014ddm041040124000c.html picture of hotspot cleaning in Funabashi

TBS video showing the Setagaya bottles being carried out of the house in yellow drums.

 

[Bodge]

Great article from the NYT on contamination in Tokyo and the Japanese media's complicity in this debacle.

http://www.nytimes.com/2011/10/15/world/asia/radioactive-hot-spots-in-tokyo-point-to-wider-problems.html?_r=1

[pg2]

"Some of the results were shocking: the sample that Mr. Hayashida collected under shrubs near his neighborhood baseball field in the Edogawa ward measured nearly 138,000 becquerels per square meter of radioactive cesium 137, which can damage cells and lead to an increased risk of cancer."

Dusty game, baseball:

 

[Jim Lagerfeld]

*I would be very interested in knowing how you tested your soil samples to determine Bq/kg along with the specific isotopes.

I posted the soil samples by regular post to the US where they were counted by a volunteer using a HPGe detector properly calibrated with a prepared cesium 137 source.

Where any other isotopes tested for?

The test focused on cesium 134 and 137 only, and as far as I know detecting strontium accurately requires a different setup completely.

As far as the cesium isotopes go, the ratio of 137 to 134 was very similar to the other results reported so far, the highest sample tested about 6500 bq/kg 137 + 5700 bq/kg 134. I suspect the strontium is everywhere, between 1:300 and 1:500 with the cesium is what we've seen so far *reported in the media recently* in Yokohama.

If you live in Japan and would like to look at the specifics, perhaps send me a private message.

 

[Astronuc]

Where any other isotopes tested for?

"where's there's cesium there's strontium" AFAIK

Not necessarily. In the case of Chernobyl, perhaps, where there was atmospheric dispersion of particulates as well as gases and volatiles.

Strontium is a alkine Earth or group 2 element. Sr-90 precursor Rb-90 has a short half-life and a low yield, so it is more likely to bound in the fuel, or dissolved in the reactor water. The precursors for Cs, Xe and I are more abundant and bit longer lasting.

We are now at 217 days or 7 months from shutdown. About 75% of fission products have decayed through their respective chains to inert non-radioactive isotopes.

The main Cs isotopes are Cs-134 and 137, although there is Cs-135, produced from Xe-135, but Cs-135 has a half-life of 2.3 million years, so the specific activity (Bq/kg) is very low. Iodine-129 is another longer-lived radionuclide with a half-life of 15.6 million years, so it's specific activity is relatively low. After slightly more than 27 half-lives, I-131 activity should have decreased by a factor of 6.8E-9.

There is a nice little app, courtesy of energyfromthorium, which shows the radionuclides as a function of time after shutdown.
http://energyfromthorium.com/2006/07/14/new-visualization-tool-for-decay-chains/

http://www.energyfromthorium.com/javaws/DecayChain.jnlp

Update: I discovered that the default fission product distribution is for U-233. For U-235 and Pu-239 fast and thermal fission yields, one needs to 'right-click' with the mouse. A popup menu then gives some options on the display. Scroll to 'Select Fission Yield', and pick the desired set. Fast fissions from U-238 are represented as yellow lines over the bars of the other sets.

Sliding the cursor along time line will show which radionuclides are present in measurable quantities at that time. It is approximate however, but a reasonable estimate.

The vertical bars are the cumulative yield for the isotopes of that mass. The dots represent the particular isotopes. Moving the mouse cursor over plot will reveals each nuclide by Z,A with information on its half-life.

It would be nice to have the isotopes reported with the activities measured.


Update: I have attached the plots for U-235 and Pu-239 fission product distributions (from thermal fissions) for 7 months after shutdown.

 

[nikkkom]

Where any other isotopes tested for?

"where's there's cesium there's strontium" AFAIK

Wrong. Find Chernobyl contamination maps. They show very graphically that Sr deposition area is significantly smaller than Cs.

So, the opposite is true: Where's there's strontium there's cesium. Lots more cesium than strontium.

Therefore, mapping contamination is actually very easy: map Cs (easy - it's gamma active), determine evacuation zones based in Cs data alone, and all other nasty stuff is inside the Cs-contaminated area.

I'm not saying that strontium should be ignored.

But some seem to think that it is some kind of sneaky invisible death which can just appear hundreds of kilometers away from source, without accompanying cesium. It can't.

 

[Bodge]

Thanks for explaining the properties of Strontium.

If it is more likely to be dissolved in water, than dispersed by air, does that mean that the majority of Strontium produced has ended up in the sea/ground/basement water?

 

[Astronuc]

Thanks for explaining the properties of Strontium.

If it is more likely to be dissolved in water, than dispersed by air, does that mean that the majority of Strontium produced has ended up in the sea/ground/basement water?

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]

Great article from the NYT on contamination in Tokyo and the Japanese media's complicity in this debacle.

http://www.nytimes.com/2011/10/15/world/asia/radioactive-hot-spots-in-tokyo-point-to-wider-problems.html?_r=1

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/1910/2011/10/1910_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/shinsai/housyasen/kunai_sokutei_kekka/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/1015/TKY201110150155.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/news/111015/crm11101522430023-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/20111015ddlk09040168000c.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:

(NHK) and http://www3.nhk.or.jp/news/genpatsu-fukushima/20111017/0700_suiteisagyo.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-fukushima/20111017/2000_hinankuiki.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-fukushima/20111018/0455_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.

[Fukushima City] municipal government is considering removal of the leaf soil (soil made up of decaying leaves) within 75 meters of local properties, pending the consent of land owners -- significantly more than the forestry ministry's 20-meter guideline.
http://mdn.mainichi.jp/mdnnews/news/20111011p2a00m0na020000c.html "Residents near Fukushima mountains face nuclear recontamination every rainfall"

Tokyo:

http://sankei.jp.msn.com/affairs/news/111015/crm11101522400022-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/1014/TKY201110140533.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/news/20111014-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.

In light of the latest discoveries, the municipal government plans to ask the central government to conduct checks in Yokohama for radioactive strontium. Checks for radioactive material are currently being conducted within a 100-kilometer radius of the nuclear plant.
http://mdn.mainichi.jp/mdnnews/news/20111017p2a00m0na019000c.html

Kawasaki (August - September):

Kawasaki City announced it measured 0.90 microsievert/hour at the side of the swimming pool in Hirama Park in Kamihirama, Nakahara-ku (special ward), exceeding the target level of 0.19 microsievert/hour set by the Ministry of Education and Science
(...) The citizen volunteer group "Peace and Smile Project Kawasaki" measured the near-surface radiation in this area on August 14, which measured 0.50 microsievert/hour at 5 centimeters off the ground. The group alerted the city.
http://ex-skf.blogspot.com/2011/08/high-radiation-right-next-to-childrens.html translating http://news.kanaloco.jp/localnews/article/1108180048/ (18 August)

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=20110908-00000028-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]

Fukushima prefecture:
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

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

Sorry if this has been asked before.

 

[Astronuc]

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

Sorry if this has been asked before.

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]

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.

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]

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.

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/20111018/t10013350041000.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/tokyo23/news/20111018-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/news/20111018-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]

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.

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]

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.

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]

 

[tsutsuji]

http://www.yomiuri.co.jp/national/news/20111019-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-fukushima/20111019/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-fukushima/20111019/1545_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/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".

http://sankei.jp.msn.com/region/news/111019/tky11101922200016-n1.htm Hagashimurayama city found radiations higher than 0.19 μSv/h at 13 locations in 6 primary schools and 2 junior high schools. A survey of ditches and rainspouts will be performed in kindergartens and nursery schools in the future.

http://www3.nhk.or.jp/news/html/20111019/t10013368281000.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://www3.nhk.or.jp/news/html/20111018/t10013350041000.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.

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/pdf/futie_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/20111019-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]

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."