In-situ tritium release (CORELLI-2 experiment) and ex-reactor ionic conductivity of substoichiometric LiAlO 2 breeder ceramics

Abstract

LiAlO 2 pellets with about 5% Li deficiency, prepared by a “wet” and a “dry” route were tested in situ for tritium release properties in nearly the same environmental conditions (CORELLI-2 experiment). Both the “wet” and “dry” route specimens were characterized by 80% of theoretical density (TD), almost fully open porosity and grain size ≤ 0.5 μm. The tritium removal rate evolution, following temperature or sweep gas changes during the irradiation, were observed to be nearly the same for both materials, in spite of their different preparation routes and impurities concentration. The ionic conductivities, as determined by impedance spectroscopy, were also similar. The presence of LiAl 5O 8 spinel phase in both samples apparently influenced the defect structure related transport properties of both lithium and tritium in these materials.