Tritium inventory in Li2TiO3 blanket

The tritium inventory in the Li2TiO3 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 H2 in the purge gas and tritium on grain surface of Li2TiO3 was obtained in this study. This equation shows that the rate of isotope exchange reaction 1 in the Li2TiO3 bed is much smaller than that was observed by the authors for Li2O, LiAlO2, Li4SiO4, and Li2ZrO3. This phenomenon is caused by a surface reaction that occurs at high temperature between Li2TiO3 and H2 in the gas phase. It was observed that the color of Li2TiO3 surface was changed from white to black, and quartz tube was corroded by this reaction. Tritium inventory in the Li2TiO3 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 H2 on purge gas of Li2TiO3 blanket gives contradictory effect.