A 200% cold-leg break accident in a Westinghouse four-loop RESAR-3S plant has been analyzed using the best-estimate code TRAC-PD2/MODI/Version 27 with updates. Three TRAC calculations have been performed. The first calculation used the best-estimate or realistic initial and boundary conditions and scenarios and the other two calculations, one with and one without locked rotor resistance, used the licensing conditions. These calculations produced the peak cladding temperatures (PCTs) of 800.5, 1072, and 1153 K, respectively. Comparison of these results with the Westinghouse licensing calculations performed in accordance with the guidelines in Appendix K of 10CFR50 shows an overall safety margin of 663 K, of which 352.5 K is due to the conservative initial and boundary conditions and scenario. The remaining 310.5 K is due to conservative physical models. The locked rotor resistance contributed∼81 K to PCT.