用于海水放射性监测的船载装置的研制

Study of the Shipborne Device for Seawater Radioactivity Monitoring

结合我国核电发展需求,研制出了一套船载海水放射性监测报警装置。该装置能快速有效监测到监测船驶过海域的海水放射性超标事件并给出报警信号,解决了现有监测方法中采集水样送回实验室分析造成大量时间消耗的问题。从测量船驶入超标海域算起,平均仅需约6.5 min就会报警,监测20 min漏报警概率低于1%。该报警装置测量耗时短、监测频率高、实时性强,能为及时发现事故、启动应急预案争取宝贵的时间,将为我国核电海域的放射性监测发挥作用。本报警装置还兼有活度测量功能,对海水样品测量1 h,137Cs的MDA达0.15 Bq/L。以"报警"为指导思想,摆脱了以"探测"为中心的传统观念,对报警概率、误报率与测量时间、报警阈值一并进行调整和权衡,提出了一套行之有效的报警参数设计方法,对于今后其它需要在短时间内报警的探测装置的设计,都可以提供借鉴。

Combining with the need of the nuclear power developing of China, we have developed a shipborne monitoring and alarm device for seawater radioactivity.The device can monitor seawater radioactivity and give out alarm signals if the activity beyond the standard.It will prevent large time consuming on the journey of sam-pling the seawater from the sea to laboratory.It takes a short time of 6.5 min averagely for the device to alarm after the monitoring ship enters the sea area with radioactivity beyond the standard.The probability of failing to alarm is 〈1%for a 20 min monitoring.The alarm device was proved to be less time-consuming, more flexi-ble and scalable to monitor.It is helpful in discovering an accident and activating contingency plans in time. The device can also measure the activities of the nuclides in seawater.The MDA of 137 Cs in seawater sample is 0.15 Bq/L for a 1 h measurement.The device is centering on＂alarm＂, instead of the traditional ideas of＂de-tecting＂.By balancing the alarm probability and misreport rate together with the measuring time, we proposed an effective method for the design of alarm devices, which may provide a reference for the designing of fast-a-larm devices in future.