Tritium behavior on SiC

SiC (silicon carbide) has been considered as one of the primary candidate materials for a first wall component in a future fusion reactor because it has been claimed that SiC has excellent high temperature properties and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, the tritium trapping capacity on the surface of SiC is experimentally obtained as about 10¹⁰ Bq/m² at the temperature range of 298K- 1073K in consideration of the static system effect. It is also observed that tritium is trapped to the surface through hydrogen isotope exchange reaction. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface is quantified at the temperature of 298K, 773K, 973K in consideration of the kinetic system effect by the numerical curve fitting method applying the serial reactor model. The reaction rate is observed to be constant at 3.48 × 10^-5 m/s. The comparison of tritium properties of SiC with that of graphite or stainless steel is also discussed.