Accident Tolerant Fuels (ATF) are being developed f to replace current zircaloy clad fuels in light water reactors (LWRs) to improve both safety and economic performance. As part of this effort, General Atomics (GA) is developing silicon carbide fiber – silicon carbide matrix composite (SiC-SiC) cladding to provide larger safety margins, high burnup capability, longer cycle lengths and uprated operation. In order to quantify the advantage of SiC-SiC over zircaloy, GA has modified the transient fuel performance code, FRAPTRAN, for modeling SiC-SiC-based cladding using public and private SiC property data and GA-developed failure models. The present work compares the performance of SiC-SiC verses zircaloy cladding around UO2 fuel for transients which can lead to damage of the fuel cladding. The transient cases selected are French CABRI reactor tests for Pressurized Water Reactor (PWR) fuel at hot coolant conditions, Japanese NSRR tests at cold coolant conditions, Halden IFA-650 and Power Burst Facility (PBF) LOC-11C. Results show the SiC-SiC cladding offers comparable or superior performance to zircaloy for the cases analyzed.