Change of tritium species in Li2BeF4 molten salt breeder under neutron irradiation at elevated temperature

The mechanism of the change of tritium chemical species from T+ to HT in Flibe (Li2BeF4) a potential liquid tritium breeding material under He + H2 purge gas was investigated by an in situ tritium release experiment. In case of low H2 partial pressure, the temporal change in HT release rate from Flibe has a dependence on the H2 partial pressure. The concentrations of four kinds of species, T+, HT, H2 and H+ dissolved in Flibe control the rate of the change of the tritium chemical species in Flibe. It is considered that, at the steady-state in the case of low H2 partial pressure, TF becomes the main chemical form of released tritium by decreasing the rate of the change of the tritium chemical species, which is caused mainly by the decrease of H2 concentration in Flibe. This decrease of H2 concentration is considered to be much larger in an actual blanket. (orig.)