A dual recirculation pump trip (2-RPT) test, conducted as a part of the Edwin I. Hatch Nuclear Plant Unit 2 (Hatch-2) startup testing, is analyzed using onedimensional reactor kinetics and point reactor kinetics options in RETRAN-02 MOD002. The nuclear data utilized in RETRAN are obtained by SIMTRAN using the three-dimensional core simulator solution by SIMULATE (RTS/7), taking into account exposure and the steady-state core conditions prior to the test. Scram does not occur during this test despite the actual sensed water level rise of ∼43 cm (water level had initially been lowered), while core power, flow, and pressure continue dropping until the natural circulation establishes a new equilibrium condition at a lower reactor power level. A combined interaction of system components is taken into account in the analysis by interfacing a detailed hydraulic model of the system, with control system models for feedwater flow and steam line pressure regulation using actual plant settings. Analysis of the actual data recorded during the 2-RPT test indicates good agreement between measured and calculated parameters. It is also demonstrated that in spite of rather large changes in the axial power distribution with time, as predicted by onedimensional reactor kinetics compared with that of the point kinetics model, a good overall agreement is reached.
