Formation of lithium-tritide by hot atom reactions of tritium produced in Pb-16Li

The release behaviors of hydrogen isotopes in Pb-16Li introduced by thermal gas exposure or produced by thermal neutron irradiation were compared to investigate hot atom reactions of tritium. The solubility of hydrogen isotope was evaluated to be S = 6.56 × 10−7 exp(−0.11 [eV]/kT) [at. fr, Pa0.5], which is consistent with the literature values. The tritium TDS spectra for Pb-16Li with thermal neutron irradiation showed that about 5% of tritium was released at single release stage around 600 K, which was higher than the melting point of Pb-16Li, although no release peak was found at around 600 K for the hydrogen isotope-doped Pb-16Li. The kinetic analysis indicated that the tritium release would be associated with the dissociation of Li-T bond, indicating that LiT was formed in Pb-16Li by thermal neutron irradiation, suggesting that the formation of Li-T bonds should be considered to estimate tritium retention in Pb-16Li eutectic blanket systems in fusion reactors.