Speaker
Description
Yi-Hyun Park1, Young Ah Park1, Mu-Young Ahn1, Haixia Wang2
1KFE, Korea, 2INEST, China
The solid type of tritium breeder is used as a pebble form due to packing phenomena, stress concentration, thermal conductance, purge gas flow, and so on. The important properties of breeder pebbles are not only physical properties but also tritium release property. This study aims at a preliminary investigation on tritium release properties of lithium metatitanate (Li2TiO3) pebbles manufactured by Powder Injection Molding (PIM) process.
Li2TiO3 pebbles with 3.4 mm in diameter were prepared by PIM process which was first try to pebble manufacturing by Korea Institute of Fusion Energy (KFE). Although Li2TiO3 pebbles with around 1 mm in diameter are foreseen to be used in breeding blanket, those with 3.4 mm in diameter were manufactured as a feasibility test by PIM process. Average grain size and porosity of Li2TiO3 pebbles were less than 1.00 µm and about 39.7 % with almost open pore type, respectively. The high-intensity D-T fusion neutron source (HINEG-CAS) was employed at the Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences (INEST, CAS) to conduct a neutron irradiation experiments. The total number of fusion neutrons was about 1.104 x 1015 n. Tritium release experiment from the irradiated pebbles was also conducted using the tritium release system from room temperature up to 800 oC. The total radioactivity of release tritium from the irradiated Li2TiO3 pebbles with 274.1 g in weight was about 1866.4 Bq. Tritium release behavior including the ratio between HTO and HT at elevated temperature was preliminarily investigated in this study.
