The invention relates to a system for detecting ionizing radiation, in real time, with electromagnetic noise protection, to be used in control circuits. According to the invention, the system consists of a detector module (1), placed in an area (5) where the ionizing radiation flux (6) is monitored, module which comprises an active detection sensor consisting of an area (13) of PIN diodes, electronic circuits needed to collect and transmit data through optic fiber, as well as a circuit for the conversion of energy of the optical radiation present at the end of an optic fiber (4) into electric energy, and an interface module (2) placed outside the area situated under the action of the ionizing radiation and the sources of electromagnetic disturbance, having the role of enabling the reception of data provided by the detector module (1) through an optic fiber (3), interfacing the same with a computer (10) and providing the energy needed for the operation of the detector module (1) as a laser beam transmitted through the optic fiber.