Electrical conductivities of dense and porous alumina under reactor irradiation

Radiation induced changes of electrical conductivity for alumina varying density were investigated during fission reactor irradiation. Radiation induced conductivity (RIC) for dense and porous alumina increased due to electronic excitation with increasing the reactor power. The RIC at the reactor full power of 50 MW with ionization dose rate of 2.3 kGy/s and fast neutron flux of 1.4-1.6×10¹⁷ n/m²s was higher by about two orders of magnitude than base conductivities at 0 MW. The RIC for porous alumina was about 3.3 times as much as that for dense alumina. The RIC of dense and porous alumina at 50 MW decreased at the initial fluence and reached a constant at fast neutron fluences of about 5.5×10²² and 2.5×10 ²² n/m², respectively and subsequently kept up to the resultant ionization dose of 4.4×10³ MGy and the fast neutron fluence of about 2.9×10²³ n/m².