Developing of modeling approach of the steam generator cracking of floating NPP

Abstract: In this work a problem of cracking of tubes of a steam generator (SG) of floating NPP (FNPP) is considered. Problem of the SG tubes cracking was experimentally investigated on similar to the FNPP reactors of nuclear icebreakers. It was concluded that main reason is in anomalously high hydrogenation of the titanium alloy of the SG tubing. For solution of this problem general mechanism of formation of gas bubbles on exit of the reactor and a transport them to problematic areas of the SG was proposed. To prove this hypothesis a multiscale, multi-physical modelling approach is developing. In application of this method to current problem a combination of 1D-3D codes is used. Features of each model and results of calculations are presented. Analysis of the calculation results allows concluding in feasibility of the proposed approach to cracking of the SG tubes.
Keywords: Floating NPP, SG tubes cracking, multiscale, multi-physical modelling, CFD code