Analysis of Overheating Rupture in Heat-Transfer Tubes Causing Corrosive High-Temperature Reaction

Hamada, Hirotsugu  ; Tanabe, Hiromi

Sodium-water reaction tests simulating intermediate water leaks into sodium are analyzed by the overheating rupture model of a heat-transfer tube exposed to the corrosive and high-temperature reaction jet. The comparison of the model with test data leads to the following conclusions: The failure behaviors of gas-pressurized tubes are classified into two types of the creep failure and the ductile failure accompanied by creep, depending on the test conditions. Thin-wall tubes fail within tens of seconds due to the ductility while thick-wall tubes fail in about 1 minute due to the creep; in the latter case, the thinning due to wastage proved to be dominant in the overheating rupture phenomena. In the creep failure and the ductile failure accompanied by creep, the times to failure in the analysis are respectively estimated 20-50 % and 35-50 % shorter than those in the experiments; namely, the analysis has a certain degree of conservatism. In the creep failure, if the time coefficient