Some history: about detection of nuclear test at the CEA-DAM

The opening to signature and ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) took 20 years in 2016, and the development of its monitoring network is almost complete. But well before that date - as early as the 1950's - the CEA-DAM had been entrusted with the task of detecting nuclear tests on behalf of the State's highest authorities. From the sensor to the detailed interpretation of recordings, a real expertise in various fields has thus been developed over the years. This has allowed France to interact at the highest level in the discussions that preceded the definition of the CTBT and its international monitoring system (IMS). Today, this expertise is internationally recognized, and France is one of the most active members of the CTBTO, that is the CTBT organization: 80% of the infra-sound stations and nearly one half of the radionuclide atmospheric measurement stations of the IMS are equipped with sensors developed at the CEA-DAM Ile-de-France. The NDC-In-A-Box software suite, distributed by the CTBTO to the member states of the treaty, includes several seismic-acoustic analysis software developed at CEA-DAM Ile-de-France, grouped under the initials DTK (for DASE Tool Kit). This expertise, dedicated to monitoring, has also allowed the CEA-DAM to position itself, at the request of the authorities, on many other related missions, the most recent being the establishment of the French national tsunami warning center - Cenalt. (authors)