Overview of Tritium-Resistant Performance of Heat Transfer Tube Materials in Reactors

Abstract Tritium, a radioactive hydrogen isotope widely distributed in fission and fusion reactors, has received considerable attention for its behavior within nuclear systems. As the sole barrier against tritium permeation from the primary to the secondary loop, the performance of heat transfer tubes in resisting tritium is extremely crucial. In future fusion reactors, where tritium serves as a fuel at higher concentrations and larger scales, its permeation issues will become even more challenging. Therefore, evaluating and developing heat transfer tube materials with high tritium resistance is paramount for advancing reactor high-temperature applications and ensuring their radiation safety. This paper reviews the model of tritium permeation through heat transfer tubes from the primary to the secondary loop, using DT as an example. It then discusses the use and composition of common heat transfer tube materials in reactors, summarizes the tritium permeation rates, diffusion coefficients, and solubility at corresponding temperatures for different alloys, and analyzes the impact of Cr and Ni content on the tritium-resisting performance of alloys. After comparison, Hastelloy XR, F82H and Incoloy 800H are selected as three alloys with high tritium-resisting performance for use as reactor heat transfer tube materials. Finally, the paper provides feasible suggestions for preventing tritium permeation, hoping to offer valuable references for tritium control and management in both fission and fusion reactors.