Determination of tritium permeation rate through T-22 in GCFR helium environment

Measurements were made on tritium permeation rates through T-22 tubular samples in the temperature range of 300/sup 0/ to 550/sup 0/C. The tritium source consists of tritium in helium containing hydrogen at 6 vol % and sufficient water vapor to maintain a hydrogen-to-water-pressure ratio of 10, the total pressure being 1.01 x 10/sup 5/ Pa (1 atm). Two tritium sources at specific activities of 2.6 x 10/sup -3/ and 3.1 x 10/sup -2/ ..mu..Ci/std cc, respectively, were used for determining how the permeation rate varies with tritium concentration. The T-22 tubular samples have a wall thickness of 0.437 x 10/sup -2/ m (0.172 in.), and two samples are used for checking the reproducibility of the results. During the measurements, the tritium diffusing through the wall of the sample is swept out with a helium-steam mixture by bubbling helium at atmospheric pressure through a water reservoir maintained at 90/sup 0/C.