Experimental study on helium gas flow through pebble bed of ceramic tritium breeder in a test blanket module

Yoshikawa, Akira; Seki, Yohji; Hirose, Takanori; Tanigawa, Hisashi; Tsuru, Daigo; Yokoyama, Kenji; Ezato, Koichiro; Suzuki, Satoshi; Enoeda, Mikio; Fukada, Satoshi*

The distributions of the helium gas flow in the pebble beds were estimated by the measurement and the calculation of the pressure drops from the view point of the effective tritium recovery in a Japanese test blanket module for ITER. The pebbles of a glass or LiTiO with the diameter of 1.0 mm were packed and the helium gas was purged with the flow rates of 0-50 L/min in the membrane box. The pressure drops on the flow rates of the helium gas was measured with the differential manometer in each pebble bed. It was observed that the distribution of the pressure drop was linearly increased with the increase of the flow rate in all the cases of the pebble beds. The pressure drop in LiTiO pebble bed was larger than that of the glass pebble bed. It was considered that the difference of the pressure drops between the different kinds of the pebbles was derived from the difference of the surface roughness of pebbles.