Abstract: The inherent safety of reactor is emphasized in the design of sodium-cooled fast reactors (SFRs), and the performance analysis of oxide fuel plays a critical role in the safety assessment of SFRs, as fuel swelling and cladding failure are key phenomena occurring during the early stages of core disruptive accidents (CDAs). The time and location of fuel failure are strongly influenced by early irradiation effects. Therefore, developing a cladding failure module for oxide fuel that incorporates thermo-mechanical behavior under irradiation and relevant failure criteria is essential for understanding fuel response during accident scenarios. FRTAC is a system-level liquid metal fast reactor safety analysis code developed by China Institute of Atomic Energy (CIAE), serves as the platform for implementing such a module. The integration of a dedicated cladding failure model into FRTAC enhances its capability to simulate fuel behavior under both steady-state and transient conditions, thereby supporting more accurate reactor safety evaluations and providing insights for fuel design improvements. To capture early irradiation effects, the developed module included models for fission gas release, fuel restructuring, mechanical behavior, and plenum pressure calculations, coupled with cladding failure criteria. The module was seamlessly integrated with the FRTAC code, enabling real-time data exchange without compromising its core functionality. Validation was conducted using representative fuel rod experiments such as FO-2, MK-I, and CABRI-2. The results show that under steady-state conditions, key parameters calculated by the module agree well with experimental data and other established codes, with relative errors within acceptable ranges. For transient scenarios, calculation errors are generally within 10%, and the trends of all parameters are consistent with expected physical behavior. The model also conservatively predicts cladding failure, providing safety margins. Overall, the results demonstrate that the developed cladding failure module can reliably simulate both steady-state and transient fuel behavior, making it offers strong support for accident safety evaluation in Chinese sodium-cooled fast reactor designs.