Comparison of Silicon Carbide and Zircaloy4 Cladding during LBLOCA

The pressure and temperature histories on cladding inner and outer surfaces during of LBLOCA (Large Break Loss of Coolant Accident) are considered as boundary conditions for the structural analyses of three cladding materials. Since SiC (Silicon Carbide) has higher yield and ultimate strengths than Zry-4 (Zircaloy-4) under the same primary stresses, SiC has higher primary safety margin than Zry-4. The temperature history, the large oscillation after the LBLOCA for all three cladding materials, is modeled the secondary stresses. But the secondary stresses converge as cladding outer pressure converges. All three cladding materials have sufficient safety margins in the secondary stress intensity.