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

¹ The Foundation for Scientific and Industrial Research (SINTEF), 7465 Trondheim, Norway
² Institute for Energy Technology (IFE), Instituttveien 18, 2007 Kjeller, Norway
³ Norwegian Institute for Water Research (NIVA), Gaustadaleen 21, 0349 Oslo, Norway
⁴ National Institute for Nutrition and Seafood Research (NIFES), PO Box 2029 Nordnes, Bergen, Norway

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.