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Vertical distributions of 137Cs and Pu in sediments of the Lake Inba after the Fukushima Daiichi Nuclear Power Plant accident
https://repo.qst.go.jp/records/65585
https://repo.qst.go.jp/records/65585b4097420-897b-4dea-aba4-5ddbd07c8870
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2015-03-12 | |||||
| タイトル | ||||||
| タイトル | Vertical distributions of 137Cs and Pu in sediments of the Lake Inba after the Fukushima Daiichi Nuclear Power Plant accident | |||||
| 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_c94f | |||||
| 資源タイプ | conference object | |||||
| 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 |
曹, 立国
× 曹, 立国× 石井, 伸昌× 鄭, 建× 田上, 恵子× 内田, 滋夫× 曹 立国× 石井 伸昌× 鄭 建× 田上 恵子× 内田 滋夫 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident happened on March 11, 2011, large amounts of radionuclides were released into the environment. The released 137Cs as well as Pu isotopes were observed in environmental samples around Fukushima, such as soil and litter. Lake Inba in Chiba Prefecture with a surface area of 11.55 km2 is one of the most eutrophic lakes in Japan. The average depth of the Lake is around 1.7 m, and it is about 220 km away from the FDNPP site. Previously, only 137Cs activity around 800 Bq/kg (decay corrected to 15 March 2011) in surface sediment was reported, and 137Cs concentrations in a few species of fish were investigated. However, temporal trends in radiocesium concentrations were not clear and information on Pu isotopes has not been studied. Thus it is necessary to further identify the contamination of radiocesium and possible Pu isotopes derived from the FDNPP. We collected two sediment cores on 11 August 2011 (Core-1) and 30 July 2012 (Core-2) at the same position in Lake Inba. Presently, 137Cs and 134Cs profiles have been determined. Because 134Cs from other sources in environment decayed out, the 134Cs/137Cs activity ratios of approximately 1 (decay corrected to 15 March 2011) observed in upper layers in the two sediment cores suggested the FDNPP accident-derived radionuclides have contaminated the sediments in Lake Inba. Moreover, the 137Cs and 134Cs activities of upper layers for Core-1 were much higher than that of Core-2. For Core-1, 137Cs and 134Cs inventories were calculated to be 32390 Bq m-2 and 30270 Bq m-2, respectively. The 137Cs and 134Cs inventories of surface sediment (0-2 cm) accounted for about 34% and 38% of total inventories of Core-1, respectively. 137Cs and 134Cs inventories were around 3757 Bq m-2 and 3528 Bq m-2 in Core-2, respectively. Meanwhile, the percentage rates for 137Cs and 134Cs inventories of surface sediment (0-2 cm) in core-2 accounted for the total inventories were 17% and 15%, respectively. Data on Pu isotopes of the cores will be obtained soon afterwards, and we will discuss the results at the symposium. | |||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 第１６回環境放射能研究会 | |||||
| 発表年月日 | ||||||
| 日付 | 2015-03-10 | |||||
| 日付タイプ | Issued | |||||
