Characteristics of uranium hydride bed for fusion fuel cycle: Hydrogen and deuterium absorption

Abstract

Metal hydride beds will become essential components in the tritium plant for the safe handling and processing of tritium gases in nuclear fusion machines. Korea has been developing metal hydride beds focusing on robustness, reliability, and longevity. In this study, the authors designed an improved uranium hydride bed and fabricated an experimental bed with a storage capacity equivalent to 70 g of tritium based on our previous research efforts. We investigated the hydrogen and deuterium absorption characteristics of the experimental bed. After uranium was successfully activated by hydrogen, absorption performance experiments based on various operational conditions in the tritium plant were conducted. Full capacity absorption was performed with a different initial temperature of uranium and the time and rate for absorption were analyzed. We found that the different absorption rates between hydrogen and deuterium are related to the difference in equilibrium pressure between uranium hydride and uranium deuteride. These experimental results will be the basis of the operation mode development and performance reference for the uranium hydride bed in the fusion fuel cycle.