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用HPGe-γ谱分析方法测定了阳江核电海域表层沉积物中238 U、226 Ra、210 Pb、228 Th、228 Ra、40 K、137Cs、134Cs、110mAg、58 Co和60Co共11种核素的比活度,238U、226Ra、210 Pb、228Th、228 Ra、40K、137 Cs等7种核素的放射性比活度范围分别为75.2～ 102.0、32.6～ 38.6、86.9～148、54.3 ～71.3、40.9 ～70.6、580 ～660和＜0.16 ～3.82 Bq/kg干重,平均值分别为82.4 ±5.2、35.5±2.0、121.7±14、60.2±3.1、57.1 ±3.1、621±29和2.21±0.31 Bq/kg干重,134Cs、110mAg、58 Co和60Co等4种核素的比活度均低于检测限.沉积物中226Ra/238 U、210 pb/226 Ra和228 Th/228 Ra比值的范围分别为0.35 ～0.48,2.63 ～4.17和0.96 ～ 1.36,平均值分别为0.43、3.43和1.06.结果显示,该海域表层沉积物中210pb相对于226 Ra过剩,226 Ra相对于238U亏损,而228Th与228 Ra基本平衡;沉积物中γ放射性核素含量水平与粒度分布、离岸距离无明显相关性.“,”Some radionuclides in surface marine sediments from Yangjiang nuclear power plant and its adjacent sea area were measured using HPGe γ spectrometer.The specific activities of 238 U,226 Ra,210 Pb,228 Th,228 Ra,40 K and 137 Cs were 75.2 ～ 102.0,32.6 ～ 38.6,86.9 ～ 148,54.3 ～ 71.3,40.9 ～ 70.6,580 ～ 660 and ＜ 0.16 ～ 3.82 Bq/kgDw,with the mean of 82.4 ± 5.2,35.5 ± 2.0,121.7 ± 14,60.2 ± 3.1,57.1 ± 3.1,621 ± 29 and 2.21 ± 0.31 Bq/kgDW,respectively.The specific activities of 134 Cs,110m Ag,58 Co and 60 Co were below the limit of method.Ratio(226 Ra/238 U) and Ratio (210 pb/226 Ra) were 0.35 ～ 0.48 and 2.63 ～ 4.17,with the mean of 0.43 and 3.43,respectively.It was shown that the uranium decay series was in disequilibrium in the surface sediments,where 210Pb relative of 226rRa were excess while 226 Ra relative of 238 U was deficient.The average value of Ratio (as Th/=8 Ra) was 1.06,ranging from 0.96 to 1.36.It was shown that 228Th and 228Ra was in equilibrium in the surface sediments.No obvious correlationship was found among the specific activities of radionuclides in sediments,the grain size characteristics and the offshore distance.