A method has been developed to aid pressurized water reactor (PWR) power plant operators in monitoring the transition of the plant from normal full-power conditions to expected post-reactor-trip conditions. Using a pressure-temperature plot or display, the operator can determine in real time whether the transition is normal or if a fault has occurred that has caused a loss of adequate reactor coolant system saturation margin, a loss of reactor coolant system heat sink, or excessive cooldown of the reactor coolant system. The method allows rapid differentiation among these faults and also has the capability of detecting multiple abnormalities. Evaluations of the technique have been performed with operators using manual plots in a classroom environment plotting data from plant transients and computer simulations. This method uses information that is currently available in PWR control rooms and that can be displayed on a cathode ray tube in the required format for analysis. This method appears to be very effective in communicating plant status to operators during a post-reactor-trip condition; application to other plant conditions is being investigated.