Sammendrag
SINTEF has calculated the spreading and deposition of 226Ra associated with discharges of produced water to sea from Norwegian offshore installations in the North Sea. The calculated concentration levels are compared to ambient environmental levels from presence of other sources (natural or anthropogenic) of 226Ra in the environment. Fluxes of 226Ra from sea water to sediment are calculated for both natural conditions and for added 226Ra originating from produced water based on various assumptions. The calculations are performed by the DREAM (Dose related Risk and Effects Assessment Model) operable at SINTEF. This model is able to simulate concentrations in the environment as a function of space and time, including discharges from multiple sources. Depositions on the sea floor caused by discharges of 226Ra are calculated as well.