Abstract
For upgrades of nuclear power plant with pressurized water reactor, it is one of the effective mean to improve the steam generator (SG) secondary flow To evaluate thermal-fluid dynamics in secondary system of SG, boiling two-phase phenomenon is needed to analyze In this study, new numerical analysis system is developing for PWR secondary system including SG and turbine system Firstly three dimensional two-phase flow analysis model of SG secondary-side is developed with two-fluid model, and we confirm that our model can estimate steam pressure of feedring type SG Secondaiy present model is applied to preheat type SG and evaluate the effect of increasing of steam pressure in secondary-side From this result, we succeeded in predicting the steam pressure increase with improving the method of feedwater supply
