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

A numerical model has been applied to simulate the fate of super(226)Ra 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 super(226)Ra. Figures are presented for the concentration levels and deposition rates of super(226)Ra in the ambient for various assumptions for the fate of the super(226)Ra in the ocean (as dissolved, as adsorbed to ambient organic particles that sink down on the sea floor, and as forming Ba(Ra)SO sub(4) particles). Concentration levels and deposition rates are compared with natural levels and fluxes of super(226)Ra 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 super(226)Ra.