Worst Case Meteorological Scenario for Norway in Case of an Accident in Sellafield Nuclear Site

Consequences for Norway in case of a hypothetical accident in Sellafield nuclear site have been of concern for Norwegian authorities for some time now. A 33-year period with meteorological data and the dispersion model SNAP was used to find out the meteorological conditions for which atmospheric transport of radioactive debris from Sellafield nuclear site to Norway is the most efficient. This was done by running the SNAP model two times each day for the entire period and selecting the situations with maximum deposition to Norwegian territory. The worst case meteorological scenario for Norway in case of a hypothetical accident in Sellafield was found on 25th of June 1989. In this meteorological situation atmospheric transport to the west coast of Norway takes only 12 h. Based on the results of the SNAP runs, the probability of reaching Norway by radioactive pollution in case of an accident in Sellafield was also analysed. Such a probability is high (25-40%) for most of the Norwegian territory, except for the northern part and very high (over 40%) for the western coast of Norway.