The capabilities of the RETRAN-02 code have been extended to allow it to perform pressurized water reactor anticipated transient without scram (ATWS) calculations. In particular, the steam property functional fits have been extended to 41.4 MPa (6000 psia) and a better steam generator simulation capability using local conditions heat transfer has been incorporated. The local conditions heat transfer model and alternate steam generator modeling techniques are described. A loss-of-feedwater ATWS was performed with RETRAN-02 and compared with vendor calculations with excellent agreement.