Computational fluid dynamics analyses of a VVER-1200 nuclear reactor vessel for symmetric inlet, asymmetric inlet, and LOCA conditions

Abstract

The nuclear reactors can undergo different forms of asymmetric operating conditions with one or more reactor coolant pump (RCP) fails or pressurized thermal shock (PTS) occurrences which can influence the life of reactor vessels. So, accurate descriptions of the heat transfer and the coolant flow within a nuclear reactor for the safety and performance concerns are always desirable. In this paper, computational fluid dynamics (CFD) simulation for a VVER-1200 reactor vessel was presented. Analyses of the reactor vessel were carried out for symmetric and asymmetric inlet boundary conditions, and also for loss-of-coolant accident conditions. Due to computational limits, some simplifications in the geometry of the RPV are introduced. As a result of the analyses, several parameters such as temperature, velocity, and pressure distributions were obtained for the whole reactor vessel. The obtained results for pressure losses through the reactor core matched with the analytical values of the VVER and the predicted thermal results agreed well with the design values. The obtained results show that it is possible to carry out further analysis for several asymmetric or accident conditions utilizing the CFD simulation knowledge obtained.