- TEPCO’s most recent airborne Cesium measurements in and around Fukushima Daiichi are either undetectable or nearly so. Cs-134 is no longer detectable at the main gate and Cs-137 is down to 1.9×10-7
bq/cc. (two 10-millionths of a radioactive emission per second) The only other location with detectable Cesium is 2km off-shore, with a reading of 5×10-8 bq/cc. Concentrations at these two locations are 1,000 to 10,000 times below national standards. The minimum level of detection is 3×10-8 bq/cc. To gain perspective on these numbers, the international limit for Radon-222 inhalation is 10 bq/cc, and its typical concentration in the USA is about 1.5×10-4 bq/cc. While Radon is an inert gas and not retained in the
body, and Cesium can be retained when inhaled, the numbers show the ultra-sensitive nature of modern radiological equipment and highly conservative exposure limits used in Japan.
- The International Atomic Energy Agency (IAEA) has presented a detailed, 80-page decontamination report to the Tokyo government. Among its suggestions, the report urges Japan to swiftly designate radioactive residue disposal sites and use them before the materials become an actual health hazard. Merely collecting contaminated material and scarping topsoil, then piling up the bagged material at a convenient location, is not a solution. While concern for local resident’s fear is commendable, using it as an excuse for delaying long term decisions is not the answer. The report also says decontamination should begin in areas proven to have the highest contamination levels, rather than the current haphazard efforts in areas below international limits where public fears have dictated action. The IAEA also urges Japan to use existing disposal facilities for residues contaminated below international limits, which is the greater volume of material to be handled. Setting standards below international limits in an effort to soothe public fears only makes the situation worse.
- A research team led by Hirohiko Ishikawa of Kyoto University’s Disaster Prevention Research Institute, measured cesium-134 and cesium-137 levels in samples of food, water and air, gathered between July 2nd and 8th, located 20 to 70 kilometers from Fukushima Daiichi. Their findings are not based on computer simulations (like those below), but on actual samples taken from the region. What they found is startling. It should be noted that they calculated internal dose from ingestion and inhalation of radioactive Cesium only, and did not include external exposures to the population, with the new, politically-correct national standard for exposure of 1 millisievert per year in mind. The research team found the average exposure for people having normal ingestion and inhalation rates is 0.003 millisieverts since March 11, 2011. If anyone only ate the most cesium-rich foods available and breathed only the most Cesium-tainted air, the dose rises to 0.16 millisieverts. Ishikawa said internal exposure from Cesium should not be something to worry about. (Asahi Shimbun)
- Nagoya University Professor Tetsuzo Yasunari and his international research team have used a computer simulation which indicates there is detectable Cesium contamination to be found as far from Fukushima Daiichi as 500 kilometers. Their simulation predicts Cesium concentrations of 250 becquerels per square meter for Hokkaido island, which is at least 500km north of Fukushima. They also predict concentrations of 25 becquerels per square meter in the northernmost mountains of Japan. While Yasunari explained these levels are nothing to be concerned about, he did say the research shows the pollution from Fukushima covers all of northern Japan. (JAIF)
- A second computer simulation, this time out of the Space Research Association of the University of Maryland, indicates the farmland near Fukushima Daiichi is unsafe to use due to Cesium impregnation of the soil. In their opinion, all of Fukushima Prefecture is “highly contaminated.” Although the team admits most of Fukushima’s farm soils are well below the national limits, they believe production and consumption of food will be severely impaired with levels down to one half (2,500 becquerels) of the government limit (5000 bq/kilogram). Some impairment will occur with levels as low as 25 bq/kg. They also predict problems for some of the Prefectures surrounding Fukushima, including Miyagi, Tochigi and Ibaraki, because the simulation indicates all three have farmlands with Cesium levels above 25 bq/kg. (Japan Times) Thus, detectable means dangerous…right?
- While widespread radiation fears have saturated the news for many months, it turns out someone has been quietly putting people’s fears to rest. Yasuyuki Fujimora, professor of engineering at Nihon University, has been circulating information on radiation and its biological effects to his neighbors in Nasu, Tochigi Prefecture, about 90 kilometers southwest of Fukushima Daiichi. After Fukushima began, he saw neighbors quarreling over leaving the area and pregnant women fearing for the lives of their unborn. No one trusted the government reports on the relative safety of low level exposures. Fujimora had been studying radiation issues ever since Chernobyl in 1986, and when his neighbors panicked over Fukushima airborne releases, he decided to do something about it. “Why not investigate the reality of radiation exposure, make scientific analyses and proceed with decontamination on our own?” he told them. He organized a group of volunteers to distribute radiological information and buy their own monitoring devices so they could follow the local situation themselves. The project expanded rapidly. “Our idea of acting together to regain a peace of mind caught on with others,” Fujimora said, “It didn’t matter whether you were a common resident or a town government official, whether you were for or against nuclear power.” The group now numbers more than 1,000. As a result, the town has had no record of residents over-reacting to so-called hot spots they have discovered, and parents of schoolchildren are acting in a responsible manner. Naoko Okutsu, a 37-year-old mother of two schoolchildren in Nasu, was one of many who sought Fujimura’s advice. She decided to not leave the city after Fujimora told her, “You should not feel afraid just because you don’t know. There is still time for action.” As a result of Fujimora’s efforts, the schools in Nasu have full classrooms and the town is literally in a state of business-as-usual. The 8-month-old project has not gone completely un-noticed, however. Similar projects are now running in the nearby cities of Nasushiobara and Otawara. (Asahi Shimbun) We have said all along the key to resolving radiation fears in Japan is education concerning the realities of radiation. Mr. Fujimora’s efforts serve notice to the value in our opinion.
- A second bottle of what appears to be radioactive Radium has been discovered on the same supermarket property in Setagaya Ward, Tokyo, where another was found last month. The new bottle produced a contact reading of 170 millisieverts, which is more than 50% higher than the first one which read 110 millisieverts. The bottle has been removed by the government. An investigation into the history of the property shows the Central Union of Agricultural Cooperatives in Tokyo has leased the land since 1999 after buying it from a school in 1973. There seems to be no record of ownership prior to 1973. Neither the Union nor store operator knows how the bottles got there. (Japan Times)
- A second set of “stress test” data has been submitted to NISA, this time by the Shikoku Electric Company for its Ikata unit #3. Shikoku says the report shows the plant can safely withstand an earthquake 1.9 times greater than the worst theorized for the region, and a tsunami up to 14.2 meters in height. The submission, however, brought strong criticism from a few of the members on the government panel recently created to review the stress tests. One said passing stress testing should not automatically allow a plant to restart because the exact cause of the Fukushima accident has yet to be “clarified”. Other say plants should not restart if local residents say “no”. (NHK World)