Department of Environmental and Resource Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark.
Department of Contaminants and Biohazards, Institute of Marine Research, P.O.Box 1870 Nordnes, NO-5817 Bergen, Norway.
Sci Total Environ. 2022 Nov 15;847:157503. doi: 10.1016/j.scitotenv.2022.157503. Epub 2022 Jul 22.
This work reports the first dataset of U and U in sediment cores taken from the Barents Sea, with the aim to better understand the source terms of anthropogenic uranium in the Arctic region. Concentrations of U and U along with Cs, and U/U atomic ratio were measured in six sediment profiles. The cumulative areal inventories of U and U obtained in this work are (3.50-12.7) × 10 atom/m and (4.92-21.2) × 10 atom/m, with averages values of (8.08 ± 2.93) × 10 atom/m and (1.08 ± 0.56) × 10 atom/m, respectively. The total quantities of U and U deposited in the Barents Sea bottom sediments were estimated to be 507 ± 184 g and 7 ± 3 g, respectively, which are negligible compared to the total direct deposition of U (6000 g) and U (40-90 g) from global fallout in the Barents Sea. The integrated atomic ratios of U/U ranging in (0.98-1.57) × 10 reflect the predominant global fallout signal of U in the Barents Sea sediments and the highest reactor-U contribution accounts for 30 ± 14 % among the six sediment cores. The reactor-U input in the Barents Sea sediments is most likely transported from the European reprocessing plants rather than related to any local radioactive contamination. These results provide better understanding on the source term of anthropogenic U in the Barents Sea, prompt the oceanic tracer application of U for studying the dynamics of the Atlantic-Arctic Ocean and associated climate changes. The U-U benchmarked age-depth profiles seem to match reasonably well with the reported input function history of radioactive contamination in the Barents Sea, indicating the high potential of anthropogenic U-U pair as a useful tool for sediment dating.
本研究报告了巴伦支海沉积物中采集的 U 和 U 的第一个数据集，旨在更好地了解北极地区人为铀的源项。在六个沉积剖面中测量了 U 和 U 与 Cs 和 U/U 原子比。本研究获得的 U 和 U 的累积面积丰度分别为（3.50-12.7）×10 原子/m 和（4.92-21.2）×10 原子/m，平均值分别为（8.08±2.93）×10 原子/m 和（1.08±0.56）×10 原子/m。估计巴伦支海底沉积物中沉积的 U 和 U 总量分别为 507±184 g 和 7±3 g，与巴伦支海全球沉降中 U（6000 g）和 U（40-90 g）的总直接沉降相比可以忽略不计。U/U 积分原子比范围为（0.98-1.57）×10，反映了 U 在巴伦支海沉积物中的主要全球沉降信号，六个沉积芯中最高的反应堆-U 贡献占 30±14%。巴伦支海沉积物中反应堆-U 的输入很可能来自欧洲后处理厂，而与任何当地放射性污染无关。这些结果有助于更好地了解巴伦支海人为 U 的源项，推动 U 作为海洋示踪剂在研究大西洋-北极海洋及其相关气候变化动力学中的应用。U-U 基准年龄-深度剖面似乎与巴伦支海放射性污染的报告输入函数历史相当吻合，这表明人为 U-U 对作为沉积物定年有用工具具有很高的潜力。
