Thermal effects of condensing water have remained local

General eutrophication of the Gulf of Finland has played a major role in the biological changes that have taken place in the sea area off Loviisa nuclear power plant. The quantities of plant nutrients in the water are now 1.5 to 2 times greater than 20 years ago. Changes attributable to the thermal effects of the power plant's cooling waters have been relatively small, and they have been restricted to the immediate surroundings of the discharge area. The most distinct environmental effects have been discovered in the temperatures of sea water, in ice conditions and in water currents within the discharge area of cooling water. The most visible biological change that has a direct link to the thermal load resulting from the power plant is the more abundant aquatic flora near the discharge point of cooling water on the southwestern shores of the Haestholmsfjaerden. Similar growth of aquatic flora has also been discovered near the discharge outlet of Olkiluoto plant, although the nutrient contents of water there are only half of the values measured in the Loviisa area. Regular radiation monitoring of the areas surrounding the nuclear power plants began before the start up of the plants. The contents of radioactive substances discovered have been small and in agreement with the release data given by the power companies. (orig.)