ELECTRICAL-PROPERTIES OF CERAMICS DURING REACTOR IRRADIATION

Twelve different types of polycrystal and single crystal Al2O3 (alumin a and sapphire) specimens of varying grades of purity were irradiated for three reactor cycles in a removable beryllium position in a High F lux Isotopes Reactor (HFIR) at Oak Ridge National Laboratory at a temp erature of 720-760 K up to a maximum dose of 3 dpa while a de electric field of 200 V/mm was applied. The recently completed Temperature Reg ulated In Situ Test (TRIST) facility in the HFIR was used to perform i n situ measurements of electrical conductivity. In addition, three Al2 O3 specimens were simultaneously irradiated without a continuously app lied de electric field. In situ electrical conductivity measurements w ere performed on the specimens before, during and following each irrad iation cycle. Behavior of electrical conduction in Al2O3 was studied, with special emphasis on detection of any long-term increase of the el ectrical conductivity. (C) 1998 Published by Elsevier Science B.V. All rights reserved.