FLUXMANCHE RADIOTRACERS MEASUREMENTS - A CONTRIBUTION TO THE DYNAMICSOF THE ENGLISH-CHANNEL AND NORTH-SEA

From 1986 to 1992, Sb-125 released by the nuclear fuel reprocessing pl ant at La Hague has been used to study the transfer of waters from mid -Channel areas towards the Straits of Dover. Since 1940, these investi gations have formed part of the MAST 53 FLUXMANCHE programme and have involved repeated measurements on a Straits of Dover transect. A discu ssion of the results is presented here which takes into account new in formation provided by a hydrodynamic model developed in the framework of FLUXMANCHE; it combines knowledge of the monthly fluxes of water tr ough the Straits of Dover and week-by-week simulation of the Sb-125 ac tivities of waters flowing in this aera. It is proposed that soluble r adionuclides introduced into the central Channel are transferred towar ds the Straits of Dover over a time which varies from four to seven mo nths depending on the route taken.