{"id":12211,"date":"2011-11-27T09:44:51","date_gmt":"2011-11-27T00:44:51","guid":{"rendered":"http:\/\/go-naminori.com\/kirbyfukunaga\/?p=12211"},"modified":"2011-11-27T09:44:51","modified_gmt":"2011-11-27T00:44:51","slug":"094451","status":"publish","type":"post","link":"https:\/\/go-naminori.com\/kirbyfukunaga\/?p=12211","title":{"rendered":"Cesium from Fukushima plant fell all over Japan"},"content":{"rendered":"
\"AJ201111260060M.jpg\"<\/a><\/div>\n

By HIROSHI ISHIZUKA of Asashi Shimbun
\nRadioactive substances from the crippled Fukushima No. 1 nuclear power
\nplant have now been confirmed in all prefectures, including Uruma,
\nOkinawa Prefecture, about 1,700 kilometers from the plant, according to
\nthe science ministry.
\nThe ministry said it concluded the radioactive substances came from the
\nstricken nuclear plant because, in all cases, they contained cesium-134,
\nwhich has short half-life of two years.
\nBefore the March 11 Great East Japan Earthquake, radioactive substance
\nwere barely detectable in most areas.
\nBut the Ministry of Education, Culture, Sports, Science and Technology’s
\nsurvey results released on Nov. 25 showed that fallout from the
\nFukushima plant has spread across Japan. The survey covered the
\ncumulative densities of radioactive substances in dust that fell into
\nreceptacles during the four months from March through June.
\nFigures were not available for Miyagi and Fukushima prefectures, where
\nthe measurement equipment was rendered inoperable by the March 11 disaster.
\nOne measurement station was used for each of the other 45 prefectures.
\nThe highest combined cumulative density of radioactive cesium-134 and
\ncesium-137 was found in Hitachinaka, Ibaraki Prefecture, at 40,801
\nbecquerels per square meter. That was followed by 22,570 becquerels per
\nsquare meter in Yamagata, the capital of Yamagata Prefecture, and 17,354
\nbecquerels per square meter in Tokyo’s Shinjuku Ward.
\nThe current air radiation level in Ibaraki Prefecture is about 0.14
\nmicrosievert per hour, equivalent to an annual dose of about 1
\nmillisievert, the safety limit for exposure under normal time
\ninternational standards.
\nLarge amounts of radioactive dust fell in Tokyo, but a separate survey
\nhas detected relatively low accumulations of cesium in the soil.
\n“Tokyo has smaller soil surfaces than other prefectures, but road and
\nconcrete surfaces are less prone to fixate cesium deposits, which were
\nprobably diffused by the wind and rain,” a ministry official explained.
\nThe fallout densities were considerably lower in the Chugoku and Kyushu
\nregions in western Japan. The smallest figure of 0.378 becquerel per
\nsquare meter came from Uto, Kumamoto Prefecture. The density in Osaka
\nwas 18.9 becquerels per square meter.
\nThe peak value in Ibaraki Prefecture was 970,000 times larger than the
\ncumulative fallout density of 0.042 becquerel per square meter in fiscal
\n2009, found in an earlier nationwide survey before the Fukushima crisis
\nstarted.
\nBefore the accident, cesium-137, which has a longer half-life of 30
\nyears, had been detected from time to time from atmospheric nuclear
\ntests. But those densities mostly stayed below 1 becquerel per square
\nmeter, while cesium-134, with a shorter half-life, was rarely detected,
\nthe ministry officials said.
\nAlso on Nov. 25, the science ministry released maps of aerially measured
\nradioactive cesium from the Fukushima plant that accumulated in Aomori,
\nIshikawa, Fukui and Aichi prefectures.
\nThis was the final batch of the 22 prefectures in eastern Japan where
\nmapping was to be completed by the end of this year.
\nNowhere in the four prefectures did the accumulations exceed 10,000
\nbecquerels per square meter, the threshold for defining an area as being
\naffected by the nuclear accident. This reconfirmed the science
\nministry’s view that radioactive plumes wafted only as far west as the
\nborder of Gunma and Nagano prefectures and as far north as the border of
\nMiyagi and Iwate prefectures, ministry officials said.
\nThe ministry also confirmed that radioactive plumes tended to drift just
\nshort of mountain ranges where they formed belts of high cesium
\nconcentrations due to rainfall and other factors. The mountain ranges
\nincluded the Ou and Iide mountains along the border of Yamagata and
\nFukushima prefectures, the Echigo mountains along the border of
\nFukushima and Niigata prefectures, the Shimotsuke mountains along the
\nborder of Fukushima and Tochigi prefectures, and the Kanto mountains
\nalong the border of Gunma and Nagano prefectures.
\nThese patterns are shown in three-dimensional plots in an online
\nJapanese-language document released by the science ministry
\n(http:\/\/bit.ly\/unIfH0).
\nThe ministry also said Nov. 25 that it will conduct aerial measurements
\nof cesium accumulations in soil in regions outside the 22 prefectures
\nstarting next year. That is because small amounts of cesium have been
\ndetected in dust deposits in Hokkaido and western Japan.<\/p>\n

<\/div>\n","protected":false},"excerpt":{"rendered":"

By HIROSHI ISHIZUKA of Asashi Shimbun Radioactive substances from the crippled Fukushima No. 1 nuclear power plant have now been confirmed in all prefectures, including Uruma, Okinawa Prefecture, about 1,700 kilometers from the plant, according to the science ministry. The ministry said it concluded the radioactive substances came from the stricken nuclear plant because, in […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":{"0":"post-12211","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-kirby-blogs"},"_links":{"self":[{"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=\/wp\/v2\/posts\/12211","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12211"}],"version-history":[{"count":0,"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=\/wp\/v2\/posts\/12211\/revisions"}],"wp:attachment":[{"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/go-naminori.com\/kirbyfukunaga\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}