Integrated experiment of blanket in-pile mockup with Li2TiO3 pebbles

Lithium titanate (Li2TiO3) is one of the candidate tritium breeding materia ls for breeding blanket of the fusion reactor. Therefore, tritium release e xperiments from Li2TiO3 packing region were carried out to evaluate the eff ects of various parameters, i.e. sweep gas flow rate, irradiation temperatu re, and hydrogen content in sweep gas, etc. on tritium release. As for the shape of the Li2TiO3, a small spherical form (pebbles) is preferred to redu ce the induced thermal stress in the breeding material. The diameter and to tal weight of Li2TiO3 pebbles were 1 mm and similar to 135 g, respectively. And the integrated experiment of blanket in-pile mockup with Li2TiO3 pebbl e bed was carried out at the Japan Materials Testing Reactor (JMTR). The tr itium released from Li2TiO3 pebble bed was swept by the helium gas with hyd rogen. The total tritium concentration (HT + HTO) and gaseous tritium conce ntration (HT) of tritium released from Li2TiO3 pebbles were measured, and H T/(HT + HTO) ratio was evaluated under various conditions. (C) 2000 Elsevie r Science B.V. All rights reserved.