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Plutonium in the western North Pacific: Transport along the Kuroshio and implication for the impact of Fukushima Daiichi Nuclear Power Plant accident
https://repo.qst.go.jp/records/74994
https://repo.qst.go.jp/records/74994992c529c-8b75-4186-8e79-38173ac11851
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2017-11-01 | |||||
| タイトル | ||||||
| タイトル | Plutonium in the western North Pacific: Transport along the Kuroshio and implication for the impact of 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_6501 | |||||
| 資源タイプ | journal article | |||||
| 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 |
Wu, Junwen
× Wu, Junwen× Dai, Minhan× Xu, Yi× Zheng, Jian× Zheng, Jian |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | This study examined the Pu source functions in the Western North Pacific (WNP) based on data collected in 2014 and 2015. The basin wide 240Pu/239Pu atom ratios ranged from 0.227–0.263 (average=0.244±0.011), consistently higher than that of global fallout (~0.180) indicating non-global fallout Pu sources. The spatial distribution of the 240Pu/239Pu atom ratio further showed overall higher 240Pu/239Pu atom ratios within the Kuroshio region as compared to the off Kuroshio zone, the main western ocean boundary current. There also occurred an overall decreasing trend along the Kuroshio path to its extension areas. The 239+240Pu activities in the surface seawater were in a wide range of 1.15–4.30 mBq m-3 and the spatial distribution showed an increasing with the latitude. We observed even heavier Pu isotopic ratios in the Kuroshio mainstream compared to the off Kuroshio zone. In contrast, the 239+240Pu activities had a different distribution pattern showing with higher values by ~ 33% in the off Kuroshio zone than those in the Kuroshio. This was attributed to a unique close-in fallout source with high degrees of scavenging on the transport along the Kuroshio. The differences in Pu isotopic ratio and activity suggested the non-global fallout Pu signature from the Pacific Proving Grounds (PPG). Higher 240Pu/239Pu atom ratio in the Kuroshio water is mainly from PPG signature transport via North Equatorial Current (NEC)-Kuroshio Current. While the high Pu isotopic ratio off the Kuroshio zone is linked to the formation and circulation of North Pacific Intermediate Water (NPIW), including North Pacific Subtropical Model Water (STMW) and Central Mode Water (CMW). We further revealed that this PPG source contributed 60±13% to the Kuroshio zone and 45±10% to the off Kuroshio zone using a simple two end-member mixing model. We suggest that the 240Pu/239Pu atom ratios and 239+240Pu activities were almost identical between before and after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, indicating that the Pu contribution originated from FDNPP accident, if any, to the WNP basin was negligible or the input flux of 239+240Pu was too small to alter the Pu isotopic composition. | |||||
| 書誌情報 |
Chemical Geology 巻 511, p. 256-264, 発行日 2019-03 |
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| DOI | ||||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | 10.1016/j.chemgeo.2018.12.006 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://www.sciencedirect.com/science/article/abs/pii/S0009254118305916?via%3Dihub | |||||
