Experiment on the Effects of Contact Between the Pressure Tube and the Fuel Assembly

Abstract

The Advanced Thermal Reactor (ATR) is a pressure tube type reactor in which the fuel assembly is located close to the pressure tube. The ATR has a structure is such that the thermal stretch of the fuel pin is not limited by the spacer if the fuel pin dries out. Accordingly, it is not thought that the fuel pin contacts the pressure tube due to large transformations around the Design Based Event (DEE). Nevertheless, the safety margin must be kept in case the over-DEE. We have confirmed in this experiment that the temperature of the pressure tube does not increase to the critical level when the fuel pin contacts the pressure tube and the functions of the pressure tube are maintained as a pressure boundary. Further. \ye analyzed the safety margin of the pressure tube using the data from this experiment and from code analysis.