A prototype of long range wireless sensor system using LPWAN Technology for radiation monitoring application has been developed. A proprietary semiconductor detector based radiation detection module is used for measuring gamma radiation dose rate in the range of 1mR/h to 1000R/h. The radiation detection module is interfaced with a RF module for transmitting measured radiation data. Selected RF Module is based on LPWAN technology and provides long range, low cost solution for radiation monitoring application. Wireless RF module consists of a wireless MCU, range extender and a PCB antenna.Wireless MCU at transmitter is programmed to transmit radiation data at a data rate of 5 kbps to cover a communication range up to 10 km. Frequency of transmission is 867 MHz, which comes under unlicensed ISM band of 865-867 MHz, in India. Wireless MCU of RF module can be programmed for higher data rates to cover shorter distances. At the receiver, received data is processed for radiation dose rate calculation. The information of radiation dose rate in R/hr, RSSI (Receiver Signal Strength Indicator) in dBm, and packet loss in % is displayed on the display unit connected to receiver.Functionality of developed prototype is verified in real radioactive environment. Communication range tests are performed at different data rates and transmitter power, in urban and rural environment for exploring upper limits on achieved communication range.