Analysis of the Peach Bottom – unit 2 BWR Turbine trip experiment by Relap5/3.2 code

This paper presents results of application of system thermal hydraulic code RELAP5/Mod3.2 in predicting the Peach Bottom Boiling Water Reactor Turbine Trip test. This experiment constitutes a challenge to test the capabilities of current computational tools in predicting realistically transient scenarios in Nuclear Power Plants. In fact, it involves strong feedbacks during the transient between thermal hydraulics and neutronics. In this framework, a reference case was run in order to simulate the interactions between the generated steam line pressure wave propagation and the instantaneous core void distribution. An overall comparison shows good agreement between the code calculations and the experimental data. A series of sensitivity analyses were also performed in order to assess the code prediction features, as well as to identify uncertainties related to the adopted thermal hydraulic parameters used for the plant modelisation.