我国相关标准水样总α、总β放射性分析方法应用中存在的问题及应对  

Problems and Countermeasures in the Application of Water Sample Gross α and Gross β Radioactivity Analysis Methods in China’s Relevant Stardards

作　　者：蒋岚[1] 吴桂标[1] 张家俊[1] Jiang Lan;Wu Guibiao;Zhang Jiajun(Guangdong Environment Radiation Monitoring Centre,Guangzhou,510300)

机构地区：[1]广东省环境辐射监测中心

出　　处：《辐射防护通讯》2019年第3期33-36,共4页Radiation Protection Bulletin

摘　　要：分析了目前我国水样总α、总β放射性测量相关标准规定方法实际应用中存在的问题,提出相应的解决办法。①标准未对样品采集和制备之间以及样品制备和测量之间的时间间隔作出规定,对于地下水或岩层渗水等224Ra含量较高的样品应在采样后48 h内尽快分析,以准确判断其总α水平;②水样残渣量过高时,会影响测量结果的准确性,可采取延长测量时间、使用大面积测量盘的方式降低探测限;③标准没有规定使用哪种α源测定低本底测量仪α道对β道的串道比,为避免使用不同α源导致的串道比差异,可使用串道比较低的固体闪烁探测器、半导体探测器的低本底测量仪测量样品,或者使用铝箔、纸片等屏蔽α射线,减少α道对β道的串道影响。We analyzed the problems existing in the practical application of current standard measurement methods forwater sample gross α and gross β radioactivity in China, and proposed the corresponding solutions. It turns out that: 1) The time interval between sample collection and preparation, and between sample preparation and measurement, are not prescribed. For samples with a higher 224Ra content such as groundwater or rock formation seepage, the analysis should be performed as soon as possible within 48 h after sampling, to accurately determine their gross α levels. 2) For samples with a higher amount of residue, which may affect themeasurement accuracy, the detection limit can be reduced by extending the measurement time and using largermeasuring disks. 3) αsources used to determinethe α, βcrosstalk ratio of measuring instruments are not specified. To avoid the crosstalk ratio difference caused by the use of different alpha sources, low background measuring instruments with a relatively low crosstalk ratio, such as those with a build-in solid scintillator or semiconductor detector, can be employed. In addition, aluminum foil, paper, etc. can shield α rays and reduce the influence of α channel on β channel.

关 键 词：总α 总β 水样分析 

分 类 号：X837[环境科学与工程—环境工程]