Validation of the point kinetic neutronic model of the PBMR

Abstract

This study introduces a new method for the validation of the point kinetic neutronic model of the PBMR. In this study the diffusion equation solution, as implemented in the TlNTE PBMR 268 MW reactor model, replaces the point kinetic model, as implemented in the Flownex V502 PBMR plant model. An indirect coupling method is devised and implemented in an external program called Flownex-Tinte-Interface (FTI) to facilitate the data exchange between these two codes. The validation study of FTI indicates that the indirect coupling method introduces small errors in data transfer between the two codes and therefore FTI is not suitable for very fast thermal hydraulic and detailed reactor simulations. However, it is accurate enough for the point kinetic validation study. The comparison between transient simulation results shows that the point kinetic parameters as implemented in V502 do not model the PBMR 268 MW correctly. Changes to some of the point kinetic parameters produced results that are more acceptable. The results also reveal that Flownex disregards any neutronic calculations after an explicit power change. Further studies on the newest PMBR 400 MW reactor should determine if the point kinetic parameters used are valid under all transient conditions. Thought must also be given into a low-level integration of TINTE and Flownex. This could solve the problem of the induced errors by the coupling method, but would increase computational time dramatically.