A precise hydrogen permeation experiment was conducted on beryllium at 735 to 1000K under a hydrogen gas pressure of 101 to 103Pa. The diffusion coefficient and the permeation coefficient were determined from the steady-state permeation and time-transient permeation, independently. The steady-state permeation rate was proportional to the square root of the H2 pressure and the time sequence of permeation rate agreed well with the theoretical one; indicating that the permeation was controlled by bulk diffusion. The temperature dependences of the permeation coefficient and the diffusion coefficient were, respectively:

Φ(mol/msPa1/2) = 1.0 x 10-6exp[-73(kJ/mol)/RT]

and

D(m2/s) = 1.3 x 10-7exp[-59(kJ/mol)/RT]

The solubility was given by:

S(mol/m3Pa1/2) = 7.1 x 100exp[-14(kJ/mol)/RT]

Hydrogen Permeation and Diffusion in Beryllium. K.Kizu, K.Miyazaki, T.Tanabe: Fusion Technology, 1995, 28[3], 1205-10