The diffusivity of T in molten Pb83Li17 alloy was determined under neutron irradiation at temperatures of between 300 and 700C. The residence time of T decreased with increasing H pressure, in He sweep gas, up to 1kPa. It then became constant. It was suggested that the T release rate was controlled only by T diffusion in the molten alloy and in the Fe container, at H pressures above 1kPa. According to residence-time data, obtained under a H pressure of 3kPa, the T diffusivity could be described by:

D (m2/s) = 2.50 x 10-7exp[-27.0(kJ/mol)/RT]

These values were slightly larger than those previously reported.

Diffusion Coefficient of Tritium in Molten Lithium-Lead Alloy (Li17Pb83) under Neutron Irradiation at Elevated Temperatures. T.Terai, S.Nagai, T.Yoneoka, Y.Takahashi: Journal of Nuclear Materials, 1992, 187[3], 247-53