Identification of sources and distribution of radiocarbon in the vicinity of La Hague nuclear reprocessing plant

The terrestrial environment in the vicinity of La Hague nuclear reprocessing plant (COGEMA) is potentially influenced by two sources (atmospheric and marine) and by three ways of radionuclides transfer: 1) atmospheric fallout from old nuclear bombs experiments, 2) atmospheric fallout from gaseous throwing out from the reprocessing plant 3) marine aerosol and degassing (sea to land transfer) bearing radionuclides originating from liquid waste from the plant. Institute for Protection and Nuclear Safety (IPSN) has organised since 1997, with the collaboration of the Groupe d'Etudes Atomiques (GEA) de la Marine Nationale and the Laboratoire des Sciences du Climat et de l'Environnement (LSCE/CEA-CNRS), studies to identify radionuclides sources (atmospheric and marine) and to provide an evaluation of the radiocarbon around La Hague nuclear reprocessing plant and to follow the concentration evolution versus time. A sampling strategy has been established to provide a map of the distribution of radio-elements around the reprocessing plant and to identify the mode of transfers, to determine the deposition rates on soil and vegetation in order to precise the transfer model of radio-element in plants. Three experiments in terrestrial environment with sampling of a bioindicator like furze has done in 1997, 1998 and 1999. In 2000, during TE-SEA cruise with the Research Vessel (RV) "Cotes de la Manche", the specific objective was to determine if there was 1 4C transfer as C 0 2 between sea to land.