Operation diagnostics for steam generators and heat exchangers of WWER type NPP,projects and goals of diagnostic systems application

WWER-440 steam generator design is analysed from the viewpoint of operation diagnostics and safety. When evaluating the design, the following damaging factors were considered: stress concentration due to excessive pressure and mechanical loads at rupture places; stationary and non-stationary thermal stresses during steady-state and transient operating regimes; vibration of components with low stiffness, primarily of heat-exchanger tubes, corrosion effects of coolants upon thin-walled structural components, primarily on heat-exchanger tubes; technological effects (joint weld and surface defects, residual stresses and oth.). Strain-gauge, vibration-acoustic and temperature measurements are discussed. The requirements to an operation diagnostics system are given consideration as well as the sensor arrangement. Separate blocks are to be connected to a computer via CAMAC system. The feasibility of diagnostic systems realization on NPPs with WWER is discussed either