Marine environmental radioactivity monitoring by "in-situ" gamma-radiationdetection

A monitoring system to observe continuously the artificial part of gamma-ra diation in the sea by valuation of the gamma-energy measured is described. By discrimination against the natural part of gamma-radiation, a limit of d etection is obtained for contaminations originating from nuclear accidents which is comparable to the detection limit of common chemical analysis meth ods for tracer nuclides. In addition, the type of radioactive source involv ed can be identified by gamma-spectra taken simultaneously. The measuring s ystem and its application in practice are described.