潮汐对滨海自动站γ辐射剂量率的影响及站址选择

The Influence of Tide on the γ Radiation Doserate of the Coastal Automatic Station and Site Selection

对本省两个核电厂的7个滨海自动监测子站,采用简化的潮间带形状及范围估算立体角,并考虑空气衰减因子,估算其对γ辐射剂量率贡献的理论值;对其剂量率数据进行傅里叶分析,得出主要潮汐分量的幅度及潮间带剂量率实际贡献值。理论值较实际值平均偏大70%左右。通过对各种误差因素的讨论,显示出理论模型简明而略偏保守的优良特征。以Haar小波本底功率谱为基础,提出潮间带相对剂量率限制值,并根据理论模型计算出不同距离的站址高度限制值。方法简明,可操作性较强,适用于各种潮汐类型。最终对滨海站址选取及布局优化提出建议。

For the 7 coastal automatic monitoring sub-stations of two nuclear power plants in the province, the solid angle of intertidal zones are estimated by using simplified shape and extent, and then considering the air attenuation factor, the theoretical values of their contribution to total gamma dose rate are estimated. Through the Fourier analysis of the dose rate data, the amplitude of the main tidal component and the actual dose rate contribution due to intertidal zone are deduced. The theoretical value is about 70% larger than the actual value.Through the discussion of various error factors, it shows that the theoretical model is concise and slightly conservative. Based on Haar wavelet power spectrum of the background, put forward the relative doserate limits of intertidal zone, and then according to the theoretical model to calculate the site height limit of different distance.The method is concise and operability, and is suitable for various types of tides. Finally put for- ward the suggestion for the coastal site selection and layout optimization.