A boiling water reactor system model for the Browns Ferry Nuclear Plant has been developed to predict reactor behavior during postulated transients and accidents. The model is based on the RETRAN-02 computer program and includes one-dimensional neutron kinetics capabilities. The model can be applied to a wide range of transients but is primarily intended for analyses of the limiting pressurization transients considered for reload core licensing. The model is qualified by comparisons to a number of startup test transients performed at Browns Ferry and to special turbine trip tests conducted at Peach Bottom.