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Release of Pu isotopes into the environment from the Fukushima daiichi Nuclear Power Plant Accident: Distribution and source identification
https://repo.qst.go.jp/records/54509
https://repo.qst.go.jp/records/545096039e201-0d5f-4382-bc49-65b8244f1d12
| Item type | 会議発表論文 / Conference Paper(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2014-09-16 | |||||
| タイトル | ||||||
| タイトル | Release of Pu isotopes into the environment from the Fukushima daiichi Nuclear Power Plant Accident: Distribution and source identification | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_5794 | |||||
| 資源タイプ | conference paper | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
鄭, 建
× 鄭, 建× 田上, 恵子× 青野, 辰雄× 内田, 滋夫× 鄭 建× 田上 恵子× 青野 辰雄× 内田 滋夫 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident led to the release of large amounts of radionuclides into the environment. In addition to the atmospheric releases, the release of highly contaminated water from the damaged reactor buildings resulted in the direct discharges of radionuclides into the sea. It has been estimated that the total amount of 137Cs released from the FDNPP accident ranged from 15-35 PBq, while for the refractory actinides, in particular, Pu isotopes, tiny amount (2x10-5% of the core inventory) was released into the environment. Released radioactive materials posed radiation threat to human society and ecosystems. Thus, source identification of radioactive contamination and long-term environmental behavior of released radioactive materials are important issues of study after the FDNPP accident. For Pu isotopes, it is difficult to estimate the contamination caused by the FDNPP accident if only Pu activity measurement is conducted due to the fact that only tiny amount of core Pu was released. Experience obtained from studies on Pu contamination in the Chernobyl accident and other global and/or regional Pu contamination events indicated that accurate determination of Pu isotopic composition (in particular 240Pu/239Pu and 241Pu/239Pu atom ratios) is essential for reliable source identification. This study will focus on the distribution of Pu isotopes in the terrestrial environment and the marine environment following the Fukushima nuclear accident and identification of the contamination sources of Pu isotopes. Using the developed analytical methods, we analyzed litter and soil samples collected in May, 2011 in the heavily contaminated forests in Fukushima prefecture. The results provided first isotopic evidence for release of Pu into the atmosphere and deposition on the ground in northwest and south of the FDNPP in the 20-30 km zones, and shed light in understanding the release process and sources in the FDNPP. 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. We estimated that the total amounts of Pu isotopes released into the atmosphere were ca. four orders of magnitude lower than those of the Chernobyl accident.3-4 Recent studies on Pu isotopes in plant, ‘balck substances’ and aerosol samples confirmed the wide distribution of Fukushima accident-derived Pu isotopes in the environment. Besides Pu release, the release of radiocesium isotopes, especially the identification of release sources will be discussed using a new tracer of 135Cs/137Cs isotopic ratio. Accurate determination of isotopic compositions of radiocesium and Pu indicated that the major release soures were the damaged reactors, but not the spent nuclear fuel pools. |
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| 書誌情報 |
Plutonium Futures 2014 proceedings p. 26-27, 発行日 2014-09 |
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| 出版者 | ||||||
| 出版者 | the American Nuclear Society | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | http://ansplutonium.omnibooksonline.com/ | |||||
| 関連名称 | http://ansplutonium.omnibooksonline.com/ | |||||
