Effect of mechanical properties in the weld zone on the structural analysis results of a plate-type heat exchanger prototype and pressurized water reactor spacer grid

Abstract

The mechanical properties in a weld zone are different from those in the base material owing to their different microstructures. A process heat exchanger in a nuclear hydrogen system is a key component to transfer high heat generated in a very high-temperature reactor to a chemical reaction that yields a large quantity of hydrogen. A spacer grid in pressurized water reactor (PWR) fuel is a structural component with an interconnected and welded array of slotted grid straps. Previous research on the strength analyses of these components was performed using base material properties owing to a lack of mechanical properties in the weld zone. In this study, based on the mechanical properties in the weld zone of components recently obtained using an instrumented indentation technique, strength analyses considering the mechanical properties in the weld zone were performed, and the analysis results are compared with previous research.