Résumé
Within the framework of the instrumentation of the future RJH reactor designed to receive the GEN IV reactor test devices, we are developing a new generation of acoustic sensors for monitoring the release of fission gases (He, Xe, Kr) in the Madison and/or Adeline devices.These sensors are based on NBT piezoelectric elements screen printed on Alumina, allowing an operating temperature of up to 400°C. This work is currently being carried out by IES Acoustic team, in collaboration with two CEA laboratories : the LDCI ( Dosimetry, Sensors and Instrumentation Laboratory) and the LISM - Instrumentation, Systems and Methods Laboratory.But this project is the continuation of a long-standing partnership for more than 15 years. Work launched in 2008 led to the development of a first version of an acoustic sensor for the on-line measurement of the release of fission gases in a fuel rod in a reactor. This development was the subject of a joint patent (FR2934409) and was put into operation in the CEA's OSIRIS experimental reactor at the end of 2010. The first tests of piezoelectric elements under neutron irradiation were carried out at SCK-CEN in Mol (Belgium). The research was continued for the optimisation and extension of the measurements in experimental reactors, in particular RJH. It made it possible to demonstrate the potential of screen printing for the production of acoustic sensors operating at high temperatures, in particular by including the search for suitable piezoelectric materials in order to remove the technological barrier constituted by the coupling of the piezoelectric transducer with the wall (metal or ceramic). Tests under irradiation were carried out in the TRIGA reactor of JSI in Ljubjana (Slovenia).Since 2015, the partnership has focused on the development of a prototype of the second-generation sensor for use in RJH conditions. After validation of the laboratory operation, this sensor is ready to be tested under real conditions of use and and in a radiative environment.The, after presenting past studies, the current RJH prototype and current developments, we will reflect on the sensor of the future and present other applications for acoustic measurements in hostile environments.