The TRI-tag is an internally powered, miniaturized radiation sensing, electronic Bluetooth Low Energy (BLE) beacon tag. It includes an integrated novel, low-power, inexpensive solid-state gamma radiation detector. The device was designed for operation in rugged environments with no maintenance for up to 3 years. The tag mechanical package is completely sealed using a sonic welding method and requires no external connectors or penetrations to the case. In one use case, it may be mounted to the Cs137 and AmBe241 source shields used in the oil and gas service industry as part of the Well Logging Mobile Source Transit Security (MSTS) V2 system designed to improve situational awareness of radioactive sources as sources move from the home base of operation to a job site and back. The TRI-tag wirelessly sends indication of device tamper or removal, gamma radiation activity count, and a globally unique identification that may be associated with the asset it is mounted to in a back-end database at the time of installation. It has an additional feature that uses Near Field Communications (NFC) wake-up to support ultra-low power consumption during the time between its manufacture up until it is installed and placed into service. Power management has been optimized to provide long-life from the internal primary batteries prior to deployment and in normal operation. The NFC technology can wake the unit from deep sleep requiring almost no battery power prior to installation. Integration of this tag with the MSTS V2 system will provide improved capability to automatically detect when a shield is added/removed to a transport (truck or overpack) and when a source is removed or added to the shield that the tag is mounted to. Because the tag can be mounted directly to a shield without cables, the radiation activity level detected is less dependent on orientation or movement of the shield within the transport as opposed to a detector mounted to the wall of the source storage compartment. This makes the tag's usage much more convenient operationally.