热释光剂量计在核电厂环境监测中的应用

Application of thermoluminescence dosimeter in environmental monitoring of nuclear power plant

目的研究岭澳核电站运营后大亚湾核电基地6台机组气态流出物排放对周围陆地环境辐射水平的影响。方法利用热释光剂量计(TLD)监测广东大亚湾核电基地外围环境辐射水平,在大亚湾核电周围陆地环境布设25个TLD监测点,每3个月左右回收热释光剂量计并测量,长期观测核电周围环境辐射水平变化。结果2011—2020年大亚湾核电基地外围环境用热释光剂量计测量得到的γ辐射剂量率年均值范围为76.7~207.1 nGy/h、均值为(123.3±5.7)nGy/h,年均值变化相对偏差范围为2%~12%,TLD监测结果、剂量率瞬时测量结果与20世纪国家环保总局组织的调查结果、核电运营前的本底水平一致。结论不同TLD监测点环境天然辐射水平差异较大,核电站周围50 km范围内的总体环境γ辐射水平没有变化,核电运行气态流出物的释放未对外围环境辐射水平产生累积影响。

Objective To investigate the effect of gaseous effluent from the six generator sets on the radiation level of the surrounding terrestrial environment in Daya Bay Nuclear Power Base after the operation of Ling’ao Nuclear Power plant.Methods The radiation level in the peripheral environment of the Base was monitored using the thermoluminescence dosi-meter(TLD).Twenty-five monitoring sites were set around the Base to investigate the variation of radiation level over a long period of time by collecting the TLDs every three months.Results From 2011 to 2020,the annualγdose rate of the 25 sites ranged from 76.7 to 207.1 nGy/h,with an average value of(123.3±5.7)nGy/h and a relative deviation of 2%-12%.The TLD monitoring and instantaneous measuring results ofγdose rate were consistent with the survey of the State Environ-mental Protection Administration in the 20th century and the baseline level prior to the operation of the nuclear power plant.Conclusion There are great differences in natural environmental radiation level across the TLD monitoring sites.The overall environmentalγradiation level within 50 km of the nuclear power base remains unchanged.The emission of gaseous effluent from the operation of the nuclear power plant does not have a cumulative impact on the radiation level of surround-ing environment.