Atlantic Ocean: Radionuclides

This article summarizes the main sources and the fate of radionuclides in the Atlantic Ocean, resulting primarily from human activity. This covers direct and indirect sources of artificial radionuclides due to global fallout from weapons testing, controlled releases from nuclear establishments, the deliberate disposal of radioactive waste, accidental inputs, and the presence of naturally occurring radionuclides, sometimes in enhanced quantities due to human activities. The distribution and behavior of radionuclides in seawater, sediments, and biota are described, being a consequence of both the nature of the source term and the fundamental properties of the radionuclides (chemical behavior, half-life). Finally, the article considers the radiological consequences due to the principal sources responsible for the maximum dose to the human population: nuclear fuel reprocessing and naturally occurring radionuclides. Keywords: Atlantic Ocean; global fallout; Sellafield; La Hague; nuclear reprocessing; NORM; radiation dose