[en] Radiation emergency preparedness systems must be able to deal with the threats posed to each country and the region as a whole. The threats from nuclear accidents differ in the various countries of the region. The most serious nuclear threats are those with cross-border implications and are generally assumed to be due to the presence of nuclear reactors of various kinds. Some countries in the region, Finland, Germany, Lithuania, the Russian Federation and Sweden, have nuclear power plants, and several countries in the region possess smaller research reactors. Other nuclear threats arise from nuclear powered naval vessels or submarines, and from nuclear powered satellites. Production, transportation, use, and disposal of radioactive materials constitute potential local nuclear hazards. Finally, terrorist use of radioactive material poses a nuclear threat to all countries. (au)