Monitoring of radioactivity in NW Irish Sea water using a stationary underwater gamma-ray spectrometer with satellite data transmission

The Irish Sea has important fishing grounds shared by several European countries and the quality of its marine environment is being closely monitored. Radioactivity has been of interest particularly in relation to authorized discharges from the Sellafield nuclear reprocessing plant on the Cumbrian coast. A "sentinel"-type device, equipped with a NaI (Tl)-based underwater gamma-spectrometer mounted on a stationary buoy, transmitting data through satellite connection, was deployed in the north-western Irish Sea.The data recorded and received in real-time indicated that no detectable significant changes occurred in the concentrations of 137Cs at the mooring site in the period September to November, 2000. Other anthropogenic gamma emitters were not detected.