Research shows much more radioactive fallout in northern and central Japan than expected
By arevamirpal::laprimavera
26 August 2011 The rest was either blown off to the ocean or landed somewhere else in Japan. Researchers at the National Institute of Environmental Studies (NIES) had their paper published in the electronic version of Geophysical Research Letters published by the American Geophysical Union on August 11, and they announced the result of their research in Japan on August 25. The paper was submitted on June 27, and they kept quiet until the research was published. The researchers at this government institute therefore knew all along how bad the contamination was all over southern Tohoku and all of Kanto and part of Chubu. Abstract of the paper titled “Atmospheric behavior, deposition, and budget of radioactive materials from the Fukushima Daiichi nuclear power plant in March 2011” by Yu Morino, Toshimasa Ohara and Masato Nishizawa, Regional Environment Research Center, National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan:To understand the atmospheric behavior of radioactive materials emitted from the Fukushima Daiichi nuclear power plant after the nuclear accident that accompanied the great Tohoku earthquake and tsunami on 11 March 2011, we simulated the transport and deposition of iodine-131 and cesium-137 using a chemical transport model. The model roughly reproduced the observed temporal and spatial variations of deposition rates over 15 Japanese prefectures (60–400 km from the plant), including Tokyo, although there were some discrepancies between the simulated and observed rates. These discrepancies were likely due to uncertainties in the simulation of emission, transport, and deposition processes in the model. A budget analysis indicated that approximately 13% of iodine-131 and 22% of cesium-137 were deposited over land in Japan, and the rest was deposited over the ocean or transported out of the model domain (700 × 700 km2). Radioactivity budgets are sensitive to temporal emission patterns. Accurate estimation of emissions to the air is important for estimation of the atmospheric behavior of radionuclides and their subsequent behavior in land water, soil, vegetation, and the ocean. […]
