Water - chemical regimes in the period of NPP start - up

Chemical phenomena accompanying assembly and start-up of nuclear power plants are considered on the basis of analysis of processes in NPP technological systems and physical and chemical properties of metal surfaces of pipelines and equipment. The main peculiarities of technological systems of NPPs with the RBMK and WWER type reactor and related to them peculiarities of changes in the state of structural material surfaces under different conditions are discussed. Corrosion processes during NPP start-up and the problems of surface pollution removal from systems and circuits of NPPs are analysed. Correlation between operational conditions of the main systems and chemical-technological regimes of preparing their surfaces for operation is shown. Recommendations on organization of chemical regimes during NPP start-up are given. It is concluded that provision of reliable trouble-free operation of NPPs is possible only in the case of optimal solution of the whole totality of physical-chemical, chemical and technological aspects of main equipment and auxiliary system operation