Amandine Morereau will defend her thesis
on Tuesday 24th November 2020 at 2:00 p.m.
at Cadarache site, Building 120,
Marina COQUERY, INRAE, Reporter Abstract
François CHABAUX,University of Strasbourg, Reporter
Jörg SCHÄFER, University of Bordeaux, Examiner
Emmanuelle MONTARGES-PELLETIER, CNRS, Examiner
Loïc DUCROS, University of Nîmes, Examiner
Frédérique EYROLLE, IRSN, Thesis Director
Hugo LEPAGE, IRSN, Co-director of thesis
Historical reconstruction from sediment cores of radionuclide concentrations and sources that transited in the Rhône and the Loire Rivers during the nuclear age.
The Rhône and the Loire are the most nuclear-powered rivers in France with several nuclear power generation centers (NPPs). From the middle of the 20th century, the uranium extraction mines located in the Loire basin produced the uranium necessary for the manufacture of nuclear fuel. On the Rhône, nuclearization begins with the construction of the first reactors intended for the production of plutonium for military use. Medicine, scientific research, agriculture and even watchmaking have also led to the introduction of artificial radionuclides or to modifying the concentrations of radionuclides of natural origin. These rivers are also the receptacles of artificial radionuclides drained from soils marked by atmospheric fallout from military nuclear tests (between 1945 and 1981), then from the Chernobyl accident (1986). Since the early 1980s, these rivers have been subject to regular monitoring. However, knowledge gaps remain concerning certain radionuclides for which analysis techniques have not been developed or concerning their origins (watershed or industries). Having long time series and knowing the origin of radionuclides is fundamental to better understand the trajectory of radionuclides at the watershed scale and to assess the time needed for these environments to clear these contaminants (resiliency). For this, sedimentary archives were collected in the sediment accumulation zones of the Rhône and the Loire, upstream of any nuclear installation (referential archive) as well as downstream of the last tributary.