Real-time acquisition and correction of temperature effect in NaI(Tl) detector-based environmental gamma radiation detection device

Environmental radiation monitoring especially around nuclear facility is needed to ensure public protection and safety. An online radiation monitoring system which continuously detects the presence of radioactive material in the environmental is important system to quickly detects uncontrolled radioactive released to the air. In this study, a radiation detection device based-on NaI(Tl) scintillation detector as part of an online radiation monitoring system has been developed and tested. During field testing, radiation count rate, and operational condition parameters which are temperature and relative humidity was collected continuously for 3 months. Data was transferred every 10 seconds with average communication delay around 0.57 second. Total number of data points is 733,725 records, and the average count rate was 653.09 cpm (σ = 81.77). Measured temperature is between 18.9 °C and 44.3 °C, while relative humidity is between 19.4 %RH and 78.6 %RH. Experimental result shows that count rate has temperature dependence. Effect of temperature to the count rate was estimated using power equation, and then the equation is used to correct the measurement data. After correction, several peaks which indicates the presence of radioactive material other than background radiation can be identified easily. In the future, further development such as radionuclide identification feature can be added to the prototype.