深圳大鹏半岛沿岸海水中~(129)I的分布特征和来源

研究核电站运行时产生并可能向周边海洋环境排放的长寿命放射性核素碘-129(129I)对生态环境的影响,应用超热中子活化分析和加速器质谱分析深圳大亚湾核电基地所处大鹏半岛沿岸海水样品中127I的质量浓度和129I的原子浓度.结果显示,核电站排水渠附近海水中129I的原子浓度(370.9×106/L),以及129I和127I原子浓度比(37.4×10-10)最大,但在5 km外的海域,即被稀释至本底量级水平,表明核电站对周边海洋环境中129I的影响甚微.该区域海水中129I仍主要来源于大气层核试验和核燃料后处理厂释放导致的全球大气放射性落尘,其目前水平对人体的辐照风险尚可忽略.

The distribution and source apportionment of 129I in coastal seawater of Shenzhen Dapeng Peninsula

For exploring the radioactively ecological impact on the surrounding ocean environment caused by the long-lived radionuclide iodine-129(129I),which is generated and may be discharged into the environment during the operation process of Guangdong Daya Bay nuclear power station and Ling Ao nuclear power station,epithermal neutron activation analysis and accelerator mass spectrometry have been utilized to analyze the concentrations of 127I and 129I in the seawater samples along Dapeng Peninsula,where Daya Bay Nuclear Power base is located.The results show that the concentration of 129I(370.9×106/L) and the N(129I)/N(127I) ratio(37.4×10-10) reach maximum in the seawater near the drain of nuclear power station,whereas both of them decrease to the radiation background level in the area 5 km away,indicating that the impac of 129I from the nuclear power plant on surrounding ocean environment is little.In this sea area 129I mainly comes from the global fallout released by the atmospheric nuclear tests and nuclear fuel reprocessing plants.The radioactive risk to the human body at its current level can be ignored.