A high-volume environmental radioactivity monitoring station integrating prompt and high-sensitivity γ-measuring systems

The automatic network of environmental radioactivity, REMRAD, managed by the National Inspectorate for Nuclear Safety and Radiation Protection (ISIN), consists of highly sensitive radiological monitoring stations through automatic sampling and spectrometric analysis systems of atmospheric particulate matter, deposited on a large filter splitted into 15 separate circular areas where the same particulate matter is collected. The extremely high detection sensitivity of the REMRAD stations is guaranteed both by the high sampling rate, up to 500 m 3 /h, and by the measurement configuration adopted. The stations are equipped with both an “early alarm” system, based on a LaBr 3 (Ce) spectrometric detection system placed in an orthogonal position with respect to the sampled filter, patented by ISIN, and which guarantees measurement sensitivity below 10 mBq/m 3 on Cs-137, and a BeGe “Broad Energy Germanium” detector type, which operates in delayed mode on the same filter, guaranteeing sensitivity below 10 µBq/m 3 , always with reference to the Cs-137 radionuclide. A customized management software integrates this powerful algorithm and allows multiple authorized recipients to receive prompt SMS and email in case of alarm or malfunctions. Indeed, these stations can operate without any operator intervention for up to a month thanks to a software that manages all the hardware devices automatically performing data acquisitions, quantitative analysis and saving measurements in a dedicate database. The energy calibration of the “On line” detector is constantly checked and updated while Quality Assurance is automatically performed every filter change on the BeGe detector by measuring a source installed on the robot.