Development of an economical walk-through radiation monitoring system

Abstract

This research aimed to develop an economical Walk-through Radiation Monitoring System (WRMS) for preventing the radioactive materials from unauthorized movement and also illegal trafficking. The developed monitoring system was constructed by mainly using of local materials and inexpensive devices. Two 3”x3” NaI(Tl) scintillation detectors were employed for gamma detection and installed in a pair of PVC pillar gate with 90cm x 200cm frame size. The system structure composed of: dual detector pulse summing counter, ratemeter, bi-directional occupancy sensor, radiation alarm warning circuit, and video surveillance recording from CCTV system. The developed system was tested by a person carry a 1 μCi of Cs-137 source walk-through the gate with approximately walking speed of 1.4 m/s. It was found that the system could detect the source and worked properly. With this level of sensitivity, it could be applied for low radiation level source security and also increasing safety control efficiency of the radiation safety officer in laboratory.