Modeling of Two-Phase Flow During Bottom Reflooding in PWRs

摘要

Described in this document are models for the thermal-hydraulic analysis of pres¬surized water reactor bottom reflooding. The solid/flow conservation equations are presented in forms compatible with the Modular Modeling System (MMS).nBased on the analytical models, two stand-alone MMS modules were developed. These modules are the stand-alone single power region forced reflood module (XF) and the stand-alone single power region gravity reflood module (XG). The modules were validated against the experiment with satisfactory results. The computer CPU time on the Cyber 77 was about one-fourth of the real reflood duration for the forced reflood module XF. For the gravity reflood module, XG, the computer CPU time was roughly equal to the real reflood duration.