A provisional assessment of radiation regimes in deep ocean environments

The introduction of high-level radioactive wastes into the deep ocean environment could, depending on the disposal option employed, result in a more or less significant increase in the radiation exposure of the local fauna. It has been conjectured that the fauna may be particularly sensitive to such a change in ambient conditions, although there is, as yet, little information on either their sensitivity to radiation, the natural background radiation regime, or the magnitude of the increased exposure which could arise from waste disposal. A knowledge of the natural radiation exposure of organisms occupying different niches provides a necessary perspective for any assessment of the impact of contaminant radioactivity. Available data on the concentrations of natural radionuclides in seawater, deep ocean sediments, and certain of the deep ocean fauna, together with simple models, for a basis for an estimation of background radiation dose rates. Investigations of the radiological consequences of deep-sea waste disposal have provided estimates of the concentrations of actinide and fission product radionuclides in deep ocean waters, and their variation with time. These data form the input for the estimation of the consequential exposure of the deep ocean fauna. The results of these preliminary studies provide an indication of the research necessary to improve understanding of the possible impact on the ecosystem of the disposal of high-level radioactive wastes into the deep ocean