June 3, 2023
Report

First Principles Modeling of Tritium Trapping in gamma-LiAlO2 Nanovoids

Abstract

Experimental STEM and APT investigations both indicate the presence of nanovoids in gamma-LiAlO2 pellets. While those nanovoids can affect the diffusion of tritium in pellets, first principles simulations have been conducted to evaluate the potential for tritium trapping by single and double cation and anion vacancies. It was found that tritium trapping allows to recover a significant amount of the formation energy cost of cation vacancy, while the trapping of tritium by anion vacancies further increase the energy cost of forming a vacancy. The simulations also indicated the potential for tritium to be trapped in various forms by forming bonds such as Al—T, O—T or T2. These results raise further questions regarding the speciation and dynamics of tritium trapped in nanovoids.

Published: June 3, 2023

Citation

Sassi M., A. Devaraj, S.R. Spurgeon, B.E. Matthews, and D.J. Senor. 2020. First Principles Modeling of Tritium Trapping in gamma-LiAlO2 Nanovoids Richland, WA: Pacific Northwest National Laboratory.