An Overview of the Irish Marine Monitoring Programme

Abstract

Since 1977, the Radiological Protection Institute of Ireland (RPII) and its predecessor the Nuclear Energy Board (NEB) have implemented a programme to monitor the levels of radioactive contamination in the Irish marine environment. The concentrations of radioactivity in fish, shellfish, sea water, sediment and seaweed have been monitored in Irish coastal waters and in the western Irish Sea. The key features of the programme are presented with an overview of its findings. The historical inputs of artificial radioactivity into the Irish marine environment are reviewed. The primary input is the discharge of low level radioactive waste from the Sellafield nuclear fuel reprocessing plant. Other sources include atmospheric weapons testing, the Chemobyl accident and minor discharges to sewage from some Irish hospitals of radionuclides used for medical purposes. The aims of the Institute's monitoring programme are outlined and the sampling, analytical and dose assessment methodologies employed are summarised. The geographical distribution of artificial radioactivity in the marine environment is described. A decrease in the activity concentration with increasing distance from Sellafield is observed. The temporal trends in the activity concentrations of contaminating radionuclides are also discussed. Finally, the committed effective doses to members of the Irish population due to anthropogenic radioactivity in the marine environment are presented. Doses have declined over the monitoring period, corresponding to the reduction in the level of marine discharges from Sellafield. These doses represent less than 1% of the annual dose limit for members of the public, as recommended by the Intemational Commission on Radiological Protection (ICRP).