Author/Authors :
V. and Chikhray، نويسنده , , Y. and Shestakov، نويسنده , , V. and Maksimkin، نويسنده , , O. and Turubarova، نويسنده , , L. and Osipov، نويسنده , , I. and Kulsartov، نويسنده , , T. and Kuykabayeba، نويسنده , , A. and Tazhibayeva، نويسنده , , I. and Kawamura، نويسنده , , H. and Tsuchiya، نويسنده , , K.، نويسنده ,
Abstract :
Given work presents the results of complex material-science studies of 1 mm diameter ceramic pebbles manufactured of Li2TiO3 + 5 mol% TiO2 ceramics before and after long-time neutron irradiation. Ceramic samples were placed in specially ampoules (six items) made of stainless steel Cr18Ni10Ti which were vacuumized and filled with helium. Irradiation of ampoules was carried out in the loop channel of WWRK reactor (Almaty, Kazakhstan) during 223 days at 6 MW power. After irradiation light-colored pebbles became grey-colored due to structure changes which generation of grey-colored inclusions (lithium oxide) with low density and microhardness. There is a radiation softening of lithium ceramic and that effect is higher for lower irradiation temperature 760 K than for 920 K. The value of maximum permissible load (pebble crash limit) at that is low and comprises ∼37.9 N. The content of residual tritium is higher for ceramic irradiated at 760 K (6.6 ± 0.6 × 1011 Bq/kg) than for ceramic irradiated at 920 K (17 ± 3 × 1010 Bq/kg). The size change indicates that pebble increase more after irradiation at 760 K than at 920 K where the bigger portion of tritium leaves the pebble. X-ray analysis shows radiation modification of Li2TiO3 + 5 mol% TiO2 phase composition and generation of new phases: LiTi2O4, LiTiO2 and Li4Ti5O12.
