In nuclear facilities, it is very significant for the monitoring and control system to accurately monitor and detect harmful radiation inside and outside the nuclear facility in a real-time manner to protect personnel, visitors, and the environment. This is because of the effect of ionizing radiations on the genetic material deoxyribonucleic acid or DNA contained in the human body and other living organisms. As a result, harmful genetic mutations can be caused and passed on to the next generations. In this study, a framework based on wireless sensors and actors’ networks is proposed to monitor the radiation levels inside and outside the nuclear facility. The sensors network is used to sense the environment, and its measurements are sent to a central device which makes the necessary analysis and passes this information to the monitoring and control system of the nuclear facility. A sensor reading validation algorithm is used to validate the sensors’ readings before being sent to the monitoring and control units; that is, to distinguish between the real events and the sensors’ faults, and finally, to have accurate and trusted measurements. After the sensors’ measurements are validated, they are tested against threshold values to detect new events and trigger the alarm system of the monitoring and control system to alert the operator to take corrective actions. Finally, the framework includes a system to enable the workers and visitors to be notified about the radiation levels in their and nearby areas. This technique is tested and investigated using the Castalia simulator. The simulation results are of great importance and show high event detection accuracy, low communication overheads between sensor devices, and low power consumption for the sensor devices.