Post-LOCA ductility of Cr-coated cladding and its embrittlement limit

Post-Loss of Coolant Accident (LOCA) ductility assessments Cr-coated Zircaloy cladding was conducted in compliance with the United States Nuclear Regulatory Commission (U.S.NRC)’s guidelines. The Equivalent Cladding Reacted (ECR) limit for oxidized on both sides, representing embrittlement process an outer-side coated near burst hole followed by ballooning, is found to be 13.8% at steam oxidation temperature 1204°C. Ring Compression Test (RCT) induces peak tensile stress inner surface specimen which crack starts propagate from brittle phases (ZrO2 and α(O)-Zr). Such characteristic RCT responsible decrease ECR claddings external as its oxygen-affected are developed surface. Outer-side gives approximately 10 minutes extra accident coping time fixed 1204°C before it reaches limit.