Water regime in secondary coolant circuit of WWER-type nuclear power plants

The problem matter is discussed of the water regime in the secondary coolant circuits of WWER-440 nuclear power plants. The risk of steam generator corrosion increases at points of salt thickening with vaporiation, this mainly below the clamps of the steam generator tubes and on some sites on the collector surface. It is thus necessary that feedwater should have the least possible concentration of salts, especially chlorides and of metal oxides. A very painful problem is erosion corrosion of carbon steel by the action of wet steam at high flow rates. The erosion corrosion decreases with increased pH of the water phase. In can also be suppressed by the choice of more resistant materials. The more resistant materials are listed recommended for the replacement of steam pipes, for tubes supplying heating steam to steam reheaters, etc. (Z.M.). 2 tabs