Heat sinks as critical ecosystems for nuclear power plants

Full text: Intensive development of atomic energy production demands the special conditions for safety exploitation of Nuclear Power Plant (NPP) reactors and their heat sinks (HS), used for discharges of the partial technological waters, contained the different radionuclides. Their concentrations in HS are not exceeded the maximum permissible values. Here we pay the additional attention to tritium generation in NPP reactors and water cleaner systems, including its migration under the different possible pathways in reactor systems and environment. Tritium transformations into tritium water and organic coupled forms, which may accumulate in HS bionts and sediments, are also under consideration. The technogenic tritium sources, localized in different elements of NPP reactors and in their technological water systems, have taken into account and analyzed under the normal and some emergency regimes of reactor exploration. The possible influence of fuel reactor cycle's prolongation on tritium contamination in heat sinks is discussed. We proposed some recommendations and counter measures for decreasing of HS tritium concentration, such as using of new reactor materials, the modifications of the existed technological schemes for the special reactor water treatment and purification and others