The RETRAN system thermal-hydraulics analysis code has been used to simulate the three turbine trip tests at the Peach Bottom Unit 2 boiling water reactor. The latest analysis used the dynamic slip, profile fit subcooled void, and point kinetics models in RETRAN-02. The results demonstrated that RETRAN is capable of simulating operational transients such as turbine trips. The analysis aided in understanding physical phenomena not well known such as the transient behavior of the steam bypass system and the pressure vessel. Experience gained in this work pointed out the importance of having good experimental data for code qualification purposes. This includes knowing the initial conditions, boundary conditions, control system and equipment parameters, and operator actions. The analysis of these three tests will be repeated in the future using one-dimensional kinetics, improved steam separator, and mechanistic subcooled voiding models.