核电站周边海域鱼类与表层沉积物中的放射性水平调查

Radioactive Level in Fishes and Surface Sediments from the Coastal Areas of Nuclear Power Plants

为科学评价核电站对周边海域生态环境的影响,文章选取4座我国沿海已运营的核电站即田湾核电站、秦山核电站、宁德核电站和福清核电站为研究对象,分别于2016年6-9月和2017年4-7月调查其周边海域鱼类和表层沉积物中主要放射性核素的比活度,并分析表层沉积物的来源。研究结果表明:核电站的运营未对周边海域鱼类和表层沉积物中的放射性水平造成影响,且鱼类中的^(137)Cs和^(226)Ra比活度远低于国家规定的食品检出限值要求;表层沉积物中的^(238)U、^(226)Ra和^(228)Ra比活度基本随纬度降低而逐渐增大,^(137)Cs比活度与早期文献测定结果相比随时间逐渐衰减;根据表层沉积物中的^(226)Ra/^(238)U平均值可知表层沉积物来源有所不同,且^(226)Ra与^(228)Ra比活度的相关性越高,表层沉积物的来源越单一。

To evaluate the effects of operating nuclear power plants on the ecological environment in the surrounding sea areas,4nuclear power plants which had been operated along the coast of China,namely Tianwan Nuclear Power Plant,Qinshan Nuclear Power Plant,Ningde Nuclear Power Plant and Fuqing Nuclear Power Plant,were selected as research objects.The specific activity of main radionuclides in fish and surface sediments in the surrounding sea areas was determined from June to September of 2016and from April to July of 2017respectively,and the sources of surface sediments were analyzed.The results showed that the operation of nuclear power plant had not affected the radioactivity level of fish and surface sediments in surrounding sea areas,and the specific activity of ^(137)Cs and ^(226)Ra in fish was much lower than the detectionlimits of national food.Specific activity of ^(238)U,^(226)Ra and ^(228)Ra in surface sediments increasedgradually with the decrease of latitude,and that of ^(137)Cs decreased with time compared with theresults of earlier literature.According to the average ^(226)Ra/^(238)U value of surface sediments,thesources of surface sediments in different areas were different,and the higher the correlation between ^(226)Ra and ^(228)Ra specific activity,the more single the source of surface sediments.