In this paper, the design and construction of an environmental radiation warning and monitoring system (ERMS) have been reported. The system is connected to the Internet and transmits information to a control center to peform an environmental radiation warning and monitoring network. The system is designed to measure the environmental radiation by the use of Nal scintillation detectors. When a nuclear accident occurs, it can automatically switch to the GM and Photodiode detectors to measure ranges of high doses and send warning signals to the control center. We used the Japanese JAERI method to calculate the dose rate from the spectrum of a multi-channel analysis board, thus making the system stable and highly sensitive. The spectrum is stabilized by changing the amplification coefficient of the pulse signal based on the change in temperature of the detectors and the consecutive observation at ⁴⁰K peak; therefore, it can identify some common environmental radioisotopes, such as ^mI, ¹³⁴Cs, ¹³⁷Cs, ⁶⁰Co... In each system, the measurement data are stored for several months, and the software in the control center enables users to control, collect, access, and store those data.

 environmental radiation warning and monitoring system, Japanese JAERI method, scintillation detector.