T. Terai et al., TRITIUM PERMEATION THROUGH AUSTENITIC STAINLESS-STEEL WITH CHEMICALLYDENSIFIED COATING AS A TRITIUM PERMEATION BARRIER, Journal of nuclear materials, 215, 1994, pp. 976-980
Chemically densified coating formed on the surface of austenitic stain
less steel (SUS 316) was examined for compatibility with molten lithiu
m-lead eutectic alloy (Li17-Pb83) and tritium permeability. The chemic
ally densified coating (CDC) consisting of SiO2 particles and a Cr2O3
matrix with a thickness of 60 mu m was unstable in contact with the mo
lten alloy as predicted from a thermodynamic calculation at 600 degree
s C, and it was degraded in several days. In an in-pile experiment, sp
ecimens with the coating on the front surface or the rear surface were
immersed in Li17-Pb83 molten alloy, and their tritium permeabilities
were measured. The permeability of the former was reduced to 1/10 of t
he ideal value in the diffusion-limited case, while that of the latter
was less than 1/100 of the diffusion-limited value even in a pure H-2
atmosphere. It is concluded that CDC is quite effective to reduce tri
tium permeability in the condition of not contacting molten Li17-Pb83
alloy.