FAST is a recently-developed numerical model for predicting one-dimensional transient, thermal non-equilibrium, two-phase flows, including the effect of heat conduction in the walls. In this report the predictions of the FAST model are compared with measurements obtained from the Westinghouse J-loop. In addition, the model has been used to predict the cross-sectional average flow conditions at the time and location of the first observed CHF, and the performance of several correlations used to predict CHF are evaluated. A new CHF correlation is also proposed.