Study of Li sub(2)TiO sub(3) + 5 mol% TiO sub(2) lithium ceramics after long-term neutron irradiation

• Published in: Journal of nuclear materials 2009-04, Vol.386-388, p.286-289
• Main Authors: Chikhray, Y, Shestakov, V, Maksimkin, O, Turubarova, L, Osipov, I, Kulsartov, T, Kuykabayeba, A, Tazhibayeva, I, Kawamura, H, Tsuchiya, K
• Format: Article
• Language: English
• ISSN: 0022-3115
• DOI: 10.1016/j.jnucmat.2008.12.111

Given work presents the results of complex material-science studies of 1 mm diameter ceramic pebbles manufactured of Li sub(2)TiO sub(3) + 5 mol% TiO sub(2) 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 [not, vert, similar]37.9 N. The content of residual tritium is higher for ceramic irradiated at 760 K (6.6 +/- 0.6 x 10 super(11) Bq/kg) than for ceramic irradiated at 920 K (17 +/- 3 x 10 super(10) 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 Li sub(2)TiO sub(3) + 5 mol% TiO sub(2) phase composition and generation of new phases: LiTi sub(2)O sub(4), LiTiO sub(2) and Li sub(4)Ti sub(5)O sub(12).