The estimated 137Cs inventory of the global ocean is ~603 PBq (1 PBq=10^15 Bq), accounting for over 60% of the total global fallout.
There are many rivers discharging a large quantity of terrestrial particulates into the China Seas as a result of soil erosion in the river drainage area. Riverine input is thus an important 137Cs source to the China Seas. Previous studies suggest the input of 137Cs from the Yangtze River and Yellow River is a major source to the ECS and YS, respectively5,26.
The input sources of 137Cs in the China Seas mainly include discharge from the Chinese nuclear power plants, the input by FDNPP, riverine input, direct deposition of global fallout and exchange with the Pacific Ocean. The output of 137Cs in the China Seas includes radioactive decay and burial. Until now, there have been no reports of 137Cs leakage from Chinese nuclear power plants in the China Seas. Previous studies confirmed the influence of FDNPP in the China Seas was minor13,24,26.
we calculate total water column 137Cs inventories of (28.05 ± 5.32) × 10^14 Bq for the SCS, (1.40 ± 0.90) × 10^14 Bq for the ECS, and (6.98 ± 5.34) × 10^12 Bq for the YS. Using the above calculated mean residence time of 137Cs in the China Seas, the 137Cs fluxes in the water column are (6.15 ± 1.16) ×10^13 Bq yr−1 for the SCS, (3.80 ± 2.45) × 10^12 Bq yr−1 for the ECS, and (5.82 ± 4.45) ×10^11 Bq yr−1 for the YS. Therefore, the total 137Cs flux in the water column of the China Seas is calculated to be (65.88 ± 14.50) × 10^12 Bq yr−1.
The total 137Cs inventory in the China Seas is roughly estimated to be 5.4 × 10^15 Bq,
Strontium-90 has been released into the environment from several sources, including atmospheric nuclear bomb tests (380 PBq) (conducted at a global scale) and from nuclear reprocessing facilities (7 PBq) and nuclear accidents (0.1–2 PBq) (conducted at a local scale) (IAEA, 2005; Povinec et al., 2012). In 2010, the total ocean inventory of 90Sr was reported to be 105 PBq, half of which exists in the Pacific Ocean (Povinec et al., 2012).
A bimonthly investigation of 90Sr activity in the ocean southeast of Jeju Island from November 2021 to January 2023 reported consistent activity over a 14-month period. No discernible temporal and spatial variations in 90Sr activity were observed. In this study, the 90Sr levels, ranging from 0.57 to 1.0 Bq m−3, were similar to the previously reported values of ∼1 Bq m−3 in the northwest Pacific Ocean before the Fukushima accident. This indicates that there is no noticeable invasion of 90Sr from other sources. Thus, it was concluded that 90Sr in southeast sea of Jeju Island still originate from global fallout. 0017番組の途中ですがアフィサイトへの転載は禁止です (ワッチョイ ff4e-aK+6)2023/09/03(日) 11:10:23.63ID:FioYqs2n0 ジャップ野党どうすんのこれ 0018番組の途中ですがアフィサイトへの転載は禁止です (ワッチョイW 7f63-CJ82)2023/09/03(日) 11:12:10.45ID:WiLfBr4F0 ほんとねえ 日本人の狂いっぷりどうにかならんのかねぇ 中国にはほんとご迷惑かけてますわな 0019番組の途中ですがアフィサイトへの転載は禁止です (アウアウウー Sae7-UR6F)2023/09/03(日) 11:12:18.33ID:gOVL5u1Ha セシウム137の濃度が0.5Bq/Lの水を300万立方メートル放出したら15億ベクレル