空气冷凝法对氚化水采集与测量的实验研究

An experimental study on collection and measurement of tritiated water vapor by air condensation method

目的测试空气冷凝法对氚化水蒸气的采集与测量性能,为更好开展核电厂外围环境空气中氚化水蒸气的监督性监测提供技术支持。方法将环境空气中的水蒸气冷凝为液态水,然后蒸馏纯化液态水样品,再用液体闪烁计数器测试水中氚的活度浓度,并对方法的精密度、准确度、探测下限等进行测试,验证方法的适用性。结果该方法实验室内多组样品测试结果相对标准偏差平均值为14.2%,相对误差范围为-9.8%~5.2%,探测下限可达13.7m Bq/m3,适用于湿润环境条件下空气中氚化水蒸气样品的采集与测量。结论该方法可用于在湿润季节时核电厂周边空气中氚化水蒸气样品的采集与测量。

Objective To test the performance of air condensation method for collection and measurement of tritiated water vapor in air, to provide technical support for monitoring of tritiated water vapor in the surrounding environment of nuclear power plants. Methods The water vapor in air was condensed to liquid water, and the liquid water sample was distilled and puri- fied, and the activity concentration of tritium in water was measured with a low background of liquid scintillation counter. The precision, accuracy and detection limit of the method are tested, and the applicability of the method were verified. Results The test results of several groups of samples in the laboratory show that, the average relative standard deviation was 14.2% , the relative error ranged from -9.8% to5.2% , and the lower detection limit was 13.7 mBq/m3, which was suitable for the collection and measurement of tritiated water vapor samples in air under humid environment. Conclusion This method can he used to collect and measure the samples of tritiated water vapor in the air around nuclear power plants in wet seasons.