Analysis of similarity criteria for experimental models and equipment of nuclear plant safety systems

Abstract

A criterial method is proposed for analyzing the adequacy of real pipeline systems with pumps of nuclear power plants and experimental installations. The method is based on an analysis of the identity of the determining criteria for the similarity of hydrodynamic processes in real and experimental conditions. The criteria for similarity of real and experimental conditions and conditions of water hammer for pipeline systems with pumps of nuclear power plants in transient and operating modes are determined. Water hammers in transient regimes are a consequence of aperiodic hydrodynamic instability of the flow; and in operating conditions - a consequence of oscillatory hydrodynamic instability. The determining factor of hydrodynamic oscillatory instability is the inertia of the pressure-supply characteristic of pumps. On the basis of the proposed method, an example of the practical application of the similarity criteria obtained for real active safety systems and an experimental plant A.V. Korolev is presented. It is shown that the necessary conditions for identicality of similarity criteria are not met and extrapolation of the results of known experiments to real conditions of active safety systems of nuclear installations with WWER reactors is not justified.