Enhanced levels of 226Ra radiation in sea water and sediment caused by discharges of produced water on the Norwegian Continental Shelf

Abstract

A numerical model has been applied to simulate the fate of 226Ra radionuclides in the ocean, generated from discharges of produced water in the Norwegian Sector of the North Sea. The model simulates the transport, dilution and the (possible) deposition on the sea floor of 226Ra. Figures are presented for the concentration levels and deposition rates of 226Ra in the ambient for various assumptions for the fate of the 226Ra in the ocean (as dissolved, as adsorbed to ambient organic particles that sink down on the sea floor, and as forming Ba(Ra)SO4 particles). Concentration levels and deposition rates are compared with natural levels and fluxes of 226Ra in the ocean and to the sediment, respectively. The added concentration levels/fluxes are found to be generally relatively small, compared to natural levels/fluxes. The reason for this is attributed to the presence of fairly high natural levels/fluxes of 226Ra. © 2009 EDP Sciences.