[en] Full text: There has previously been a series of severe accidents and other events around the world, which has lead to health effects and severe consequences to the environment as a result of ionising radiation. Some of the most severe accidents have been related to explosions or fires in nuclear installations and high dose levels due to orphan sources. Even though the Norwegian nuclear industry is limited, it has since the Chernobyl accident in 1986 been Norwegian policy to have a particular emergency preparedness towards nuclear or radiological events. In order to maintain an effective emergency preparedness with limited resources, it is necessary to have a good understanding of possible scenarios and related consequences. Norwegian authorities are therefore continuously assessing nuclear and radiological threats. Norwegian emergency preparedness has to a large extent been directed towards scenarios where an accident at a foreign nuclear installation leads to radioactive volumes of air passing over Norway, causing considerable deposition over large geographical areas. Norway is neighbouring the Kola Peninsula, where there was a considerable nuclear development during the cold war. Due to their close vicinity to the Norwegian border and poor conditions at some of the sites, possible accidents at nuclear installations on the Kola Peninsula in Russia have been emphasised in Norwegian emergency preparedness. However, Norwegian and international efforts have contributed to improve the conditions at several sites on the Kola Peninsula. Improved safety and physical protection at these sites have reduced the risk for cross-border contamination. Furthermore, extensive decommissioning and dismantlement of aged nuclear submarines have reduced the number of nuclear objects of particular concern. Meanwhile, the latest changes in the international security environment have made one consider a new set of scenarios, involving e.g. massive attacks on nuclear installations. Aging nuclear installations, proliferation of nuclear weaponry and an international nuclear power renaissance have also contributed to change the Norwegian perception of nuclear and radiological threats. The consequences of the tsunami in East Asia in December 2004 has lead to an increased understanding of the authorities' responsibilities concerning Norwegian citizens and interests abroad, also with respect to nuclear and radiological events that will not bear any impact on Norwegian territory. In particular, the increasing attention towards the economic potential in the Russian High North, implies new challenges regarding an increased Norwegian establishment in an area with still many problems concerning radioactivity.Finally, awareness is also directed towards future climate changes and challenges related to nuclear safety and radioactive contamination. (author)