陆丰核电周边海域表层沉积物放射性核素比活度水平研究初探

本文采用γ能谱法对陆丰核电周边海域表层沉积物中的放射性核素进行分析测定。研究表明, 陆丰核电周边海域表层沉积物样品中的铀系核素衰变不平衡:210Pb相对于226Ra过剩；226Ra相对于238U缺损。钍系核素228Th和228Ra则接近衰变平衡。与我国部分海域沉积物放射性含量相比，陆丰核电周边海域表层沉积物样品中核素238U、228Th的放射性比活度值位于中等水平，其余核素（40K、226Ra、210Pb、228Ra 、 137Cs）的比活度值均接近于南海东北部表层沉积物核素比活度值。总体而言，研究海域表层沉积物样品放射性水平与历史数据无明显差异，处于本底范围。

A preliminary study of radioactivity level of surface sediments in the coastal area of Lufeng nuclear power plant

Radionuclides in the surface sediments from Lufeng nuclear power plant and its adjacent sea area of the South China Sea were measured using γ spectroscopy method. It was shown that the uranium decay series were in disequilibrium in the surface sediments, where 210Pb relative of 226Ra were excess and 226Ra relative of 238U were deficient. Meanwhile, the thorium decay series were close to decay equilibrium. Compared with the radioactive content of sediments in some sea areas of China, the specific activity of 238U and 228Th were at medium level. The content of 40K, 226Ra, 210Pb, 228Ra and 137Cs were close to sediment of the northeastern South China Sea. In a whole, the radioactivity level of sediments from Lufeng nuclear power plant and its adjacent sea area had no significant difference with historical data and was in the normal background range.