Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accident

The Fukushima Daiichi nuclear power plant (DNPP) accident caused massive releases of radioactivity into the environment. The released highly volatile fission products, such as 129mTe, 131I, 134Cs, 136Cs and 137Cs were found to be widely distributed in Fukushima and its adjacent prefectures in eastern Japan. However, the release of non-volatile actinides, in particular, Pu isotopes remains uncertain almost one year after the accident. Here we report the isotopic evidence for the release of Pu into the atmosphere and deposition on the ground in northwest and south of the Fukushima DNPP in the 20–30 km zones. The high activity ratio of 241Pu/239+240Pu (> 100) from the Fukushima DNPP accident highlights the need for long-term 241Pu dose assessment, and the ingrowth of 241Am. The results are important for the estimation of reactor damage and have significant implication in the strategy of decontamination

Effects of ionizing radiation and other toxic agents: laboratory experiments in NIRS -Effects on ecological microcosms-

Japan-Ukraine international meeting on radioecology: 20 years after Chernobyl, what should be next

デンリ ホウシャセン ト タ ノ ドクセイ インシ ガ スイケン マイクロコズム ニ オヨボス エイキョウ ノ ヒカク ヒョウカ

京都大学0048新制・論文博士博士(農学)乙第11112号論農博第2460号新制||農||860(附属図書館)学位論文||H15||N3749(農学部図書室)UT51-2003-C682(主査)教授 齊藤 眞弘, 教授 三野 徹, 教授 川端 善一郎学位規則第4条第2項該当Doctor of Agricultural ScienceKyoto UniversityDA

Mathematical model approach to understand the ecological effect under chronic irradiation

Although aim of the environmental protection is conservation of ecosystem, there are only a fewstudies focusing on the effect of radiation on ecosystem. To understand the ecological effect of irradiation,microbial ecosystem, "microcosm", which contains minimum components of ecosystem such as producer,consumer and decomposer, is useful because the natural ecosystem is too complex. The microcosmconsists of three species, i.e. Euglena (producer), Tetrahymena (consumer), and E. coli (decomposer). Themathematical model and computer simulation model were also developed to understand the mechanism ofecological interaction using the results of acute exposure experiments of the microcosm, and we predictedTetrahymena, which is the most radio-resistant among the constituent species, would be most sensitive inthe chronically irradiated microcosm as a result of an indirect effect due to population decrease in E. coli.Recently we started chronic exposure experiments. The microcosms were irradiated with gamma-rays at dose rateof 1.2Gy/day, 5Gy/day, 10Gy/day and 23Gy/day. From preliminary results, we found that the predictionfrom the models was different from the experimental results. Therefore, in this study, we improved ourmathematical model and discuss the difference between the model and experiments

Equi-dosimetry of deleterious factors at the level of populations and commuinities of aquatic organisms

A principally new ecological tool is proposed for comparing equivalent effects of very different factors at the levels of populations and communities as the new approach - equi-dosimetry of effects by radiations (ionizing and ultra-violet), acidification and metals as well as any other deleterious impacts

Unique Features of a Pine Tree for Monitoring and Modeling of Environmental Tritium

From a view point of provision of useful and relaiable monitoring data for test exercises of environmental tritium trandfer models, a pine tree is examined on its suitability as a bio-indicator for monitoring. Since the current model test exercises focus on the uptake, formation and translocation of organically bound tritium (OBT) in food crops, our monitoring program was desined to obtain useful information in different parts of the pine tree by uptake of tritium through the atmosphere and soil. Monitoring was conducted in the vicinity of tritium discharge sources. The observations allow the discussion of dependencies of OBT formation in the foliage part or wood part of the pine tree on an air-foliage pathway or soil-root pathway. As conclusions the usefulness and unique features of a pine tree as a bio-indicator for minitoring and modeling are highlighted.第７回トリチウム科学技術国際会

Reorganization of Advanced Radiation Emergency Medicine Systems in Japan after the Fukushima Nuclear Power Plant Accident.

The Japanese organizational system for radiation emergency medicine was reorganized and strengthened after the Great East Japan Earthquake and the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant accident on 11 March 2011. In prefectures with or near nuclear facilities (within a 30 km radius), “nuclear emergency core hospitals”, which have sufficient functions, staff, and facilities, were newly designated after the accident by the prefectural governments. “Nuclear emergency medical cooperative institutions” were also registered in the prefectures. At the national level, these hospitals are assisted by two types of national-level centers, namely “advanced radiation emergency medical support centers” and “nuclear emergency medical support centers”. Additionally, to coordinate these support centers, the NIRS-QST was designated as the “core advanced radiation emergency medical support center” by the Nuclear Regulation Authority in April 2019. The new NIRS-QST Core Center is striving to strengthen our educational and training courses, to improve the contents of educational and training materials, to develop common guidelines/manuals for biological and physical dose measurement and estimation, and cultivate human resources in the field of radiation emergency medicine in Japan