Thermal conductivity of compressed ceramic breeder pebble beds : Reimann, J. and Hermsmeyer, S. Fusion Engineering and Design, 2002, 61–62, 345–351

Abstract

Tritium breeder materials are fundamental to the development of a nuclear fusion reactor. One of the materials in investigation is lithium titanate, which has good thermal stability, high density of lithium and low activation under irradiation, fundamental properties that are demanded to this type of materials. However, few studies have been carried out on this material in order to know its more relevant properties and so to allow for the design of a material with the optimal characteristics to be used in a fusion reactor. This work presents a theoretical investigation on possible occupation sites for tritium atoms in the lithium titanate structure using ab initio Hartree Fock (HF) method. Two octahedral sites are compared with substitutional sites studied previously. This study shows that one of the octahedral sites is more favorable for the occupation of a tritium atom followed for substitutional sites. The octahedral site near the titanium layer is not favorable mainly for structural aspects. Tritium located at the most favorable sites does not affect the structural and electronic stabilities of the material.