85Kr在线监测原型装置研制

用NaI（Tl）探测器和小型数字化谱仪组成一套后处理厂排放⁸⁵Kr在线监测原型装置，并开发相应的应用软件。该装置具有远程控制功能，可实现数据获取、分析及传输的远程操作，具有连续运行和间歇运行两种工作模式。在间歇运行模式下，可通过增大测量容器内的气体压力，进一步提高探测灵敏度和监测可靠性。在实验室条件下，测量时间为1200s时，装置的实际探测下限为3.4×10⁴Bq/m³，判断限为1.7×10⁴Bq/m³。当报警阈值设置为装置探测下限、测量容器内压力大于417kPa时，装置能对浓度高于8.1×10⁴Bq/m³的⁸⁵Kr气体进行可靠监测及报警。报警的漏报率和误报率均小于0.1%。

Development of On-line Monitoring Prototype Equipment for 85Kr

A prototype equipment composed of a NaI(Tl) detector and a small digit-gamma-ray spectrometer for on-line monitoring of ⁸⁵Kr was designed and set up, and a set of corresponding software was developed. The equipment has remote control and alarm functions, and it can remotely acquire, analyze and transfer data, work at the continuous or intermittent mode. The equipment working at the intermittent mode is more sensitive than working at the continuous mode. In laboratory, when the measurement time is 1 200 s, the detection limit of the equipment for ⁸⁵Kr is 3.4×10⁴ Bq/m³, and the judging limit is 1.7×10⁴Bq/m³. When the measurement time is 1 200 s , the gas pressure in the measurement container is more than 417 kPa, and the threshold value of alarm is set to be the detection limit, the equipment can work well, and the rates of both misinformation and failure are less than 0.1% for ⁸⁵Kr concentration of more than 8.1×10⁴Bq/m³.