Environmental spill modelling and risk assessment of Orimulsion 400 and Heavy Fuel Oil

摘要

An integrated oil spill modelling system was set up for I/S Sjaellandske Kraftvaerker (SK Power). The purpose of the project was to carry out a risk assessment for accidents during transport of Orimulsion 400 and Heavy Fuel Oil (HFO) to the Asnses Power Plant and a subsequent assessment of the environmental effects. The project dealt with oil spill modelling and assessment of environmental risks to the aquatic ecosystem, to seabirds and to the coastal environment. Two fuel products were considered, Orimulsion 400 and Heavy Fuel Oil (HFO), with the purpose of comparing the environmental risk associated with the transportation through Danish waters to the Asnses Power Plant in Kalundborg Fjord. Two spill positions in the northern part of the Great Belt were considered and the fate and effects were modelled for three different seasons. Three different models were combined for modelling of the fate of Orimulsion 400 and HFO spills. A hydrodynamic model was used to provide the basis for the oil spill model, a particle model described the transport of "imaginary" particles and an oil spill fate model described the physico-chemical processes affecting the oil, such as evaporation, dispersion and solubility in the water column. For the two positions (Hatter Barn & Asnaes) the fate of a 17,000 tonnes spill during spring, summer and autumn/winter was modelled for both products. In conclusion the simulations showed that the model is capable of producing realistic scenarios including a comparative assessment of the environmental risks associated with the spill of different oil types.