Influence of grain-size and carbonate impurities on the tritium release from lithium orthosilicate

Study on the chemical compatibility between Li2TiO3 ceramic pebbles and diverse advanced structural materials

“…As can be seen from previous reports that grain size plays an important role in tritium releasing behavior 37 . The tritium release performance is likely to be better in ceramics with small grain sizes due to providing more diffusion channels, and the Li 2 TiO 3 ceramic pebbles are suggested to have grain size under 5 μm 38,39 . To observe the gain size of Li 2 TiO 3 ceramic pebbles at 700 °C under He+0.1 % H 2 environment.…”

“…37 The tritium release performance is likely to be better in ceramics with small grain sizes due to providing more diffusion channels, and the Li 2 TiO 3 ceramic pebbles are suggested to have grain size under 5 μm. 38,39 To observe the gain size of Li 2 TiO 3 ceramic pebbles at 700 • C under He+0.1 % H 2 environment. Figure 17 shows the SEM pictures of the cross-section of the Li 2 TiO 3 pebbles contacted with the different structural materials.…”

Out-of-pile tritium release study on Li4SiO4 pebbles from TRINPC-I experiments

“…Second, most of tritium (tritium gas) was released in this work at a peak temperature (about 476°C) higher than Refs. [5,11,12] (lower than 450°C). Usually, isotope exchange reactions between tritium on grain surfaces and hydrogen in purge gas are rather slow at temperatures lower than 400°C and the reaction will accelerate with increasing temperature [7,10,13], and therefore isotope exchange reactions may have a more significant effect in this work and would release more tritium gas at higher temperatures.…”

“…The Li 4 SiO 4 pebbles are usually made by a melting and spraying method [6], whereas the irradiated pebbles provided in this work were made by a freeze-drying method. Previous investigations indicated that tritium release behavior is influenced by many factors, including grain size, pebble densities, impurities, closed porosity etc., all of which will be affected by the preparation conditions of the breeder pebbles [5,6,11,[14][15][16]. Usually, the diffusion speed of tritium in the grain bulk will slow down as the grain size, density and closed porosity of pebbles become larger.…”

Fabrication of fine‐grained Li2TiO3 ceramic with enhanced performance using high‐energy ball milling

“…It was reported that interconnected pores and small grain sizes were helpful to ameliorate tritium release efficiency 2,10 . Wedemeyer et al 11 . carried out the tritium annealing studies and the in‐pile irradiation tests, which demonstrated that tritium release from small‐grained samples was faster than that from coarse‐grained ones.…”