NSUF 25-5476: Evaluation of Microstructural Integrity of ATR-Irradiated Yttrium Hydride (YHₓ)

This project aims to evaluate the microstructural integrity of ATR(Advanced Test Reactor)-irradiated yttrium hydride (YHx), a material of interest for neutron moderation, reflection, and hydrogen storage in advanced nuclear systems. We will investigate the hypothesis that ATR irradiation induces defects and microstructural changes, including dislocation loop formation, helium and vacancy bubble nucleation, radiation-induced segregation, recrystallization, and modifications to grain boundary character. To achieve these objectives, we will employ high-resolution techniques such as SEM-EDS, EBSD, and TEM. SEM-EDS will provide compositional maps and identify secondary phases, while EBSD will generate orientation maps to assess grain size, texture, and recrystallization. TEM will quantify dislocation loop densities, void volume fractions, and helium bubble distributions. Specimens, both irradiated and unirradiated, will be prepared using mechanical polishing and focused-ion-bean lift-out-methods. The potential impact of this research includes significant advancements in the understanding of the irradiation response of yttrium hydride. The study will yield high-resolution datasets capturing the microstructural and chemical evolution of YHx, offering critical insights for both fundamental research and practical engineering applications in nuclear environments. These datasets will provide essential input for multiscale models and guide the development of radiation-tolerant hydride materials. The expected period of performance is 12 months from the project award date. Anticipated scientific outcomes include detailed data on defect accumulation, grain boundary evolution, and crystallographic changes in YHx under ATR irradiation. The results will support the validation and calibration of predictive models such as phase-field and crystal plasticity simulations. Findings will be disseminated through peer-reviewed publications, conference presentations, and contributions to NSUF and IAEA databases, thereby enhancing the broader scientific understanding of radiation effects on hydride materials.

Additional Info

Field Value
Awarded Institution Idaho National Laboratory
DOI 10.46936/NSUF/60015708
Embargo End Date 2028-01-22
Facility Tech Lead Noé Morales
NSUF Call FY 2025 Super RTE Call
PI Ella Kartika Pek
PIE Facilities Irradiated Materials Characterization Laboratory
Prep Facilities Analytical Laboratory, Irradiated Materials Characterization Laboratory
Project Member Dr. Fei Teng, Staff Scientist - Idaho National Laboratory (https://orcid.org/0000-0003-3832-9138)
Project Member Dr. Tsvetoslav Pavlov, Distinguished Postdoctoral Associate - Idaho National Laboratory
Project Member Dr. Sobhan Patnaik, Staff Researcher - Idaho National Laboratory (https://orcid.org/0000-0003-2113-828X)
Project Member Dr. Ella Kartika Pek, Postdoctoral Research Associate - Idaho National Laboratory (https://orcid.org/0009-0000-2553-2511)
Project Type RTE
Sample Identifiers 13779,13801,13805