Fractional scaling analysis of cladding temperature in large break loss of coolant accident

Abstract

In integral test facilities, some phenomena relevant in the separate effect test are usually neglected due to scaling limitations and design compromises. The typical heat transfer phenomenon in reactor core in large break loss of coolant accident (LBLOCA) scenario is analyzed with fractional scaling analysis (FSA) method in this work. A conservation form of cladding temperature is derived on the basis of energy conservation. Then the scaling criteria and their importance are evaluated. It is found that the similarities of the criteria for convection heat transfer and heat accumulation should be guaranteed since their priorities are high. The contribution of initial pressure and distribution of coolant inventory to cladding temperature in LBLOCA scenario is too slight. This work is encouraging and may shed a light on the coupling application of hierarchical two-tiered scaling (H2TS) and FSA method in engineering application.