Handbook on the Material Properties of Yttrium Hydride for High Temperature Moderator Applications

Technical Report · Tue Jun 01 04:00:00 UTC 2021

DOI:https://doi.org/10.2172/1808171· OSTI ID:1808171

Hu, Xunxiang ^[1]; Wang, Hsin ^[1]; Linton, Kory ^[1]; Le Coq, Annabelle ^[1]; Terrani, Kurt A. ^[2]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Ultra Safe Nuclear Corporation (United States)

Yttrium hydride is an optimal choice for a high-temperature moderator material in advanced thermal neutron spectrum reactors that require small core volumes. A complete database of the thermomechanical properties of yttrium hydride is not yet available, although it is much needed to understand and predict the moderator performance during service in reactors. This milestone report presents the properties of unirradiated bulk yttrium hydride as a function of hydrogen concentration—including density, crystal structure, specific heat capacity, thermal diffusivity, thermal conductivity, hardness, elastic/shear moduli, Poisson’s ratio, fracture strength, microstructure, and thermal stability. This information provides a baseline measurement for the subsequent neutron irradiation response study of yttrium hydride. The recommended empirical treatment of the data is suggested. In addition, other properties (i.e., hydrogen retention, thermal hydrogen migration, and irradiation response) requiring investigation are discussed. Also included are the Preliminary post-irradiation examination (PIE) data of yttrium hydride irradiated at 600 and 900°C to 0.1 dpa in the High Flux Isotope Reactor (HFIR). The thermophysical properties have insignificant change following this low dpa irradiation for both irradiation temperatures.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1808171
• Report Number(s): ORNL/TM-2021/2074
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE