FN Archimer Export Format PT C TI Improving Knowledge of Water-Mass Circulation in the English Channel Using Radioactive Tracers BT AF BAILLY DU BOIS, Pascal ROZET, M THORAL, K SALOMON, Jean-Claude AS 1:;2:;3:;4:; FF 1:;2:;3:;4:PDG-DOP-DCB-DYNECO-PHYSED; SI BREST SE PDG-DOP-DCB-DYNECO-PHYSED UR https://archimer.ifremer.fr/doc/1997/acte-559.pdf LA English DT Proceedings paper DE ;English channel;Tritium;Radioactive tracer;Watre mass circulation AB New tools are now available to make more accurate deteminations of radio-tracer distribution : - Repositioning of station locations at the same tide reference-time, giving a homogeneous spatial data set, coupled with the possibility of interpolating and quantifying the amounts of dissolved radioactivity flowing through the English Channel. - The first measurements of tritium (3H) in seawater on a large scale in the English Channel demonstrate that this fully conservative radionuclide is a clearly identifiable marker of industrial releases. Recent campaigns carried out during the FluxManche II CCE (1994) programme show the general distribution of dissolved radionuclides 137Cs, 134Cs, 125Sb and 3H in the English Channel and Irish Sea. The re-utilization of data from previous campaigns (1983, 1986 and 1988) provides indications, at any given location in the English Channel, about the average dilution and distribution of releases derived from the La Hague reprocessing plant . Excesses and losses of radionuclides are now quantified with respect to known source-terms ; estimates of losses are provided for non-conservative radionulides, while an excess of 137Cs was observed in the English Channel during the period 1983 - 1994. This excess would represent about 1% of Sellafied releases entering the Channel. These results confirm and give a more detailed picture of the previously known distribution of water masses in the English Channel. They lead to clear information about transit times and dilution at this scale, and provide directly comparable data for the validation of hydrodynamic models. PY 1997 PD APR CT Radioprotection - Colloques, volume 32, C2, April 1997, pp. 63 - 69 ID 559 ER EF