METHOD FOR MANAGING WATER-CHEMISTRY

摘要

The purpose of the present invention is to improve the operation reliability and to reduce exploitation costs in nuclear power equipment by managing the water-chemistry in order to reduce the rate of deposit formation on the heating surfaces, to reduce the intensity of the corrosion process, including local corrosion types, to improve radioactivity conditions during the maintenance, to increase the efficiency of bypass filtration and to reduce the value of the sludge component in the heat-carrier. This method comprises introducing a correction additive that consists of reactive aluminium in an ionic or hydroxide form into the heat-carrier circulating in the circuit. The quantity of Al<3+> moles added is at least twice larger than the quantity of Fe<+2> in-going moles. The aluminium is dosed so that its molar concentration PAl in the heat-carrier is at least twice larger than that of the bivalent iron PFe in said heat-carrier. The aluminium is introduced in the heat-carrier in a composition of feedwater or a condensate which are fed through an aluminium-containing system. The aluminium dosage is carried out in a bypass filtration line of the circuit by feeding the heat-carrier through an aluminium-containing system such as an aluminium alloy. The aluminium dosage is carried out by electro-chemical dissolution of metallic aluminium, by loading special aluminium-containing pellets into a dosing unit or by adding alkaline-metal aluminates or aluminium hydroxides into the heat-carrier. The aluminium can also be introduced by the application of coatings or by the formation of oxide films that contain aluminium on the inner surfaces of the circuit.