Radioactive materials are an attractive target for terrorist or criminal groups, because they can be used throughout the world in applications including agriculture, industry, medicine, scientific research, transport, and water desalination. Criminals can build dirty bombs by using these radioactive materials. The dirty bomb has harmful consequences on humanity. Keeping radioactive materials from any malevolent human attack is a must. Therefore, this work aims to strengthen the Physical Protection System (PPS) in nuclear facilities against criminal activities. This system works to provide the detection function of adversary actions through integrating various components. These components include Internet-of-Things (IoT) controller, magnetic sensors, vibration sensors, and Passive Infra-Red (PIR) motion detection sensors with cloud-based IoT platform and mobile application for monitoring and auditing purposes, remotely. The proposed work is intended for securing nuclear facility that contains radioactive materials through detection using various sensors and IoT controllers. A controller detects trigger signals from any sensor, an alarm and warning signs are sent to the dashboard and smartphone over the Internet.