Tritium inventory in Li 2TiO 3 blanket

Abstract

The tritium inventory in the Li 2TiO 3 blanket of a nuclear fusion reactor is discussed in this paper. The method of tritium inventory estimation was proposed by the present authors. The overall mass transfer coefficient of the isotope exchange reaction 1 between H 2 in the purge gas and tritium on grain surface of Li 2TiO 3 was obtained in this study. This equation shows that the rate of isotope exchange reaction 1 in the Li 2TiO 3 bed is much smaller than that was observed by the authors for Li 2O, LiAlO 2, Li 4SiO 4, and Li 2ZrO 3. This phenomenon is caused by a surface reaction that occurs at high temperature between Li 2TiO 3 and H 2 in the gas phase. It was observed that the color of Li 2TiO 3 surface was changed from white to black, and quartz tube was corroded by this reaction. Tritium inventory in the Li 2TiO 3 blanket estimated in this study is about ten times larger than for any other solid breeding blanket at 973 K. It must be also cared that most tritium is released as HTO in this case. The use of He with H 2 on purge gas of Li 2TiO 3 blanket gives contradictory effect.