Program for French radioactivity alert network modernization

French radioactivity alert networks, set up shortly after the Chernobyl accident, have today more than fifteen years of existence. Some components of these networks (computers, probes, etc) are growing old today and their replacement is becoming essential. Before beginning this programme, IRSN wished to benefit from the experience feedback of the European countries and began technical visits in 2006. Since 2007, studies concerning the sensors allowing the measurement of the ambient gamma dose rate in the air, as well as the development of prototypes for airborne particulates and water radioactivity measurement were initiated. In parallel, the development of a centralizing interface for all data was launched, with the aim of proving the technical feasibility of the adopted solution but also allowing the first tests of the various apparatuses. IRSN intends to modernize the whole tools by the end of 2009. This presentation deals with the results of the IRSN study, particularly concerning the European technical feedback synthesis and the first achievements of the modernizing project. (orig.)