Abstract：
The risks from radioactive wastewater release from nuclear facilities into the ocean are a global concern. Radioactive contaminants, such as tritium (3H), in both forms of tissue free water tritium (TFWT) and non-exchangeable organically bound tritium (NE-OBT), can be incorporated into marine biota and cause radiation doses to biota and future consumers. However, no studies have been conducted to measure both forms of 3H in marine fish as well as evaluate the residence time in the vicinity of a nuclear fuel reprocessing facility. Here, fish from a brackish lake and from the Pacific Ocean coastline of Japan, which are near such a facility, were collected between 2006 and 2021. The reprocessing facility was operational between 2006 and 2009, during which time about 300 times more tritiated water was discharged per year into the ocean compared to the period when the facility was not operational. During operation the annual release was 30 times higher than the treated water released annually from Fukushima Daiichi. As expected, TFWT and NE-OBT concentrations increased in marine fish during operations and had peak values of 3.59 ± 0.03 and 0.56 ± 0.03 Bq/L, respectively. Total dose rates to the fish were 36,000 times lower than the 10 μGy h-1 benchmark. Concentrations gradually decreased to pre-operational levels as the facility was turned off with NE-OBT taking twice as long. Fish sampled from the brackish lake tended to have more incorporated TFWT and NE-OBT concentrations than ocean fish. This indicates that ocean tides might have contributed to the accumulation of discharged tritiated water in the lake via a narrow water channel, which highlights the importance of examining all marine ecosystems in future operations. In both marine environments, the estimated committed effective dose using the highest observed data through ingestion was well below public limits (91,000 times lower).
摘要：
从核设施释放到海洋的放射性废水的风险是全球关注的问题。放射性污染物,如氚(3H)，在两种形式的组织自由水氚（TFWT）和非交换有机结合的氚（NE-OBT），可以纳入海洋生物群，并对生物群和未来的消费者造成辐射剂量。然而,尚未进行研究来测量海鱼中两种形式的3H以及评估核燃料后处理设施附近的停留时间。这里,来自咸湖和日本太平洋海岸线的鱼，在这样的设施附近，是在2006年至2021年之间收集的。后处理设施在2006年至2009年之间运行，在此期间，与该设施不运行期间相比，每年向海洋中排放的氚化水约为300倍。在运行期间，每年的释放量比福岛第一核电站每年释放的处理水高30倍。不出所料,在操作过程中，海鱼的TFWT和NE-OBT浓度增加，峰值分别为3.59±0.03和0.56±0.03Bq/L，分别。鱼的总剂量率比10μGyh-1基准低36,000倍。随着NE-OBT花费两倍的时间关闭设施，浓度逐渐降低至运行前水平。与海洋鱼类相比，从微咸湖采样的鱼类往往具有更多的TFWT和NE-OBT浓度。这表明海洋潮汐可能有助于通过狭窄的水道在湖中积累排放的tri水，这突出了在未来运营中检查所有海洋生态系统的重要性。在两种海洋环境中，使用通过摄入观察到的最高数据估计的承诺有效剂量远低于公共限值(低91,000倍).
