[en] The Sillamaee Metallurgical Plant was established in 1948 at Sillamaee, North-East Estonia. Target product was uranium, mostly in form of yellow cake (U₃O₈) for Soviet nuclear program. Uranium ore processing continued from 1948 to 1977, totally more than 4 million tons of uranium ore were processed at Sillamaee plant. In early 1970s the plant introduced a new production line - rare earth elements. Rare earths were until 1991 produced from loparite (later from pre-processed loparite) - rare earths, niobium, tantalum and NORM-containing ore for Kola peninsula, Russia. All wastes were discharged to a large, 40 ha liquid waste depository - tailings pond, what in Sillamaee case was designed to discharge all liquid constituents slowly to the Baltic Sea. All uranium related activities were stopped in 1990, when only rare earth and rare metal production lines remained operational. The plant was 100 % privatized in 1997 and is today operated by Silmet Ltd., processing annually up to 8 000 tons of rare earth and 2000 tons of niobium and tantalum ores. The historical tailings pond, containing ca 1800 tons of natural uranium and ca 800 tons of thorium, was found geotechnically unstable and leaking to the Baltic Sea, in mid 90s. Being a problem of common Baltic concern, an international remediation project was initiated by Estonian Government and plant operator in 1998. In cooperation with Estonian, Finnish, Swedish, Danish and Norwegian Governments and with assistance by the European Union, the tailings pond will be environmentally remediated - dams stabilized and surface covered, by end of 2006. Close-down and environmental remediation of the tailings pond provides plant an ultimate challenge of discontinuing the use of liquid waste depository and re-arranging completely and cost-effectively entire waste management system. One of the most complicated areas is solid NORM-waste management: according to drafted concept of new waste management system, the plant will produce ca 100-1500 tons of solid NORM-containing residue with activity between 1000 and 5000 Bq/g annually; NORM is represented by U-238 and Th-232. However, under conditions of tense work schedule, the plant is planning waste streams' separation, retrievable interim storage for separately NORM-containing and non-radioactive solid residue; and liquid streams pre-treatment with steps of acid regeneration. (author)