Main results of long-term high lithium burn-up irradiation test in LiTiO and LiTiO + 5mol% TiO ceramics for solid breeding blanket
Tazhibayeva, I.*; Kenzhin, E. A.*; Kulsartov, T.*; Beckman, I.*; Chikhray, E.*; Shestakov, V. P.*; Kuykabaeva, A.*; Maksimkin, O.*; Kawamura, Hiroshi; Tsuchiya, Kunihiko
The paper contains the results of the integrated material study of lithium ceramics LiTiO and LiTiO + 5mol% TiO enriched by Li (up to 96%). The ceramics were irradiated in the WWR-K reactor during 5350 hours under the temperature range of 400-900С with study of tritium generated during irradiation. The post-radiation studies allowed to determine quantity of residual tritium, degree of lithium burn-up, strength characteristics of lithium ceramic with the lithium burn-up up to 20-23%, ceramic density, changes in the sample microstructure, heat characteristic of the ceramics and their changes due to neutron irradiation, changes of element and phase composition of the samples, and the parameters of tritium release from lithium ceramics. It was showed that the ceramic samples irradiated under lower temperature are characterized by sufficiently small degree of Li burn-up. It was established that irradiation resulted in softening of lithium ceramic; at that the effect is more prominent for lower irradiation temperatures. The quantity of tritium released during a reactor's campaign is somewhat increasing with increase of a campaign's number, but quantity of tritium released from lithium titanate per hour doesn't depend on duration of irradiation. Thus, despite of lithium burn-up, tritium flow from lithium titanate isn't changed during long-term irradiation since reduction of the strength of the tritium source (due to lithium burn-up) is compensated by increase in mobility of tritium in defect lattice. The obtained results showed that a breeder on the basis of Li-enriched lithium titanate can be a permanent source of tritium during one year of reactor operation at least.