Important Progress in the research of yttrium hydride high-temperature moderator

Recently, the research team at the Shanghai Institute of Applied Physics (SINAP), Chinese Academy of Sciences (CAS) has made important progress in the preparation, microstructure evolution and dehydrogenation mechanisms of yttrium hydride, which has a high hydrogen content and uniform distribution. The relevant findings have been published in reputable journals, such as the International Journal of Hydrogen Energy and the Journal of Materials Research.

Yttrium hydride, with its high hydrogen density, excellent thermal conductivity, low neutron absorption cross-section, and high-temperature resistance, is an ideal candidate for moderator materials in small-scale, high-temperature nuclear reactors. The research team has successfully synthesized a series of yttrium hydride moderator materials with varying stoichiometries. These samples are characterized by uniform hydrogen distribution, high hydrogen content, structural integrity, and superior mechanical and thermal properties. The microstructural and crystallographic evolution of yttrium hydride during Spark Plasma Sintering (SPS) process has been investigated to understand the densification mechanisms and dehydrogenation behavior. Additionally, the relationship between microstructure and performance was explored by evaluating the density, H/Y ratio, and thermal-mechanical properties of yttrium hydride under different sintering conditions. These research findings establish a correlation between the technology-microstructure-property relationships of yttrium hydride, providing valuable data support and theoretical guidance for its practical application.

This work was supported by the Chinese Academy of Sciences President’s International Fellowship Initiative and Key Laboratory of Thorium Energy, Shanghai Institute of Applied Physics, Chinese Academy of Sciences.

Link:
https://doi.org/10.1016/j.ijhydene.2024.12.146
https://doi.org/10.1016/j.mtcomm.2024.108866
https://doi.org/10.1016/j.jmrt.2024.08.171