Kaizer Jakub, Aoyama Michio, Kumamoto Yuichiro, Molnár Mihály, Palcsu László, Povinec Pavel P
Faculty of Mathematics, Physics and Informatics, Comenius University, 84248 Bratislava, Slovakia.
Institute of Environmental Radioactivity, Fukushima University, 1-1 Kanayagawa, Fukushima, Japan.
J Environ Radioact. 2018 Apr;184-185:83-94. doi: 10.1016/j.jenvrad.2018.01.015.
Impact of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident on tritium (H) and radiocarbon (C) levels in the water column of the western North Pacific Ocean in winter 2012 is evaluated and compared with radiocesium (Cs) data collected for the same region. Tritium concentrations in surface seawater, varying between 0.4 and 2.0 TU (47.2-236 Bq m), follow the Fukushima radiocesium trend, however, some differences in the vertical profiles were observed, namely in depths of 50-400 m. No correlation was visible in the case of C, whose surface ΔC levels raised from negative values (about -40‰) in the northern part of transect, to positive values (∼68‰) near the equator. Homogenously mixed C levels in the subsurface layers were observed at all stations. Sixteen surface (from 30 in total) and 6 water profile (from 7) stations were affected by the Fukushima tritium. Surface and vertical profile data together with the calculated water column inventories indicate that the total amount of the FNPP1-derived tritium deposited to the western North Pacific Ocean was 0.7 ± 0.3 PBq. No clear impact of the Fukushima accident on C levels in the western North Pacific was observed.
评估了2012年冬季福岛第一核电站事故对北太平洋西部水柱中氚（³H）和放射性碳（¹⁴C）水平的影响，并将其与该地区收集的放射性铯（¹³⁷Cs）数据进行了比较。表层海水中的氚浓度在0.4至2.0 TU（47.2 - 236 Bq m⁻³）之间变化，遵循福岛放射性铯的趋势，然而，在垂直剖面中观察到了一些差异，即在50 - 400米深度处。对于¹⁴C而言，未观察到相关性，其表层Δ¹⁴C水平从断面北部的负值（约 - 40‰）升高到赤道附近的正值（约68‰）。在所有站点的次表层均观察到¹⁴C水平均匀混合。16个表层站点（总共30个）和6个水柱剖面站点（总共7个）受到福岛氚的影响。表层和垂直剖面数据以及计算得出的水柱存量表明，沉积到北太平洋西部的源自福岛第一核电站的氚总量为0.7 ± 0.3 PBq。未观察到福岛事故对北太平洋西部¹⁴C水平有明显影响。
