Tritium diffusion in Al/sub 2/O/sub 3/ and BeO

Journal Article · Sat Jan 01 04:00:00 EST 1977 · J. Am. Ceram. Soc.; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1977.tb15493.x· OSTI ID:7087690

Fowler, J D; Chandra, D; Elleman, T S; Payne, A W; Verghese, K

Tritium diffusion in aluminum and beryllium oxides was studied by recoiling tritium into specimens and measuring the time rate of tritium release during postirradiation heating. Results were consistent with classical diffusion solutions and gave single values for the diffusion activation energy over the temperature range of measurement for single-crystal, sintered, and powdered specimens. Varying amounts of tritium were released as tritiated water even after attempts to remove most of the water absorbed by the specimens. Condensable amounts of tritium ranged from approximately 20% for single-crystal specimens to as high as 90% for some powders. Alumina containing 0.2% MgO gave tritium diffusion coefficients 4 to 5 orders of magnitude higher than those for undoped Al/sub 2/O/sub 3/, implying a significant impurity effect on tritium diffusion. Measured diffusion coefficients were many orders of magnitude lower than hydrogen diffusion coefficients in metals. When a simple equilibrium permeation model was used which neglected tritium partition effects at interfaces and enhanced diffusion along grain boundaries, it was shown that thin coatings of beryllium or aluminum oxides on metal substrates could markedly reduce tritium permeation rates through metals. The present results may be applied in the future to fusion reactors where tritium inventories will be high and tritium diffusion within the blanket region undesirable.

• Research Organization: North Carolina State Univ., Raleigh
• OSTI ID: 7087690
• Journal Information: J. Am. Ceram. Soc.; (United States), Journal Name: J. Am. Ceram. Soc.; (United States) Vol. 60:3-4; ISSN JACTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
360206 -- Ceramics
Cermets
& Refractories-- Radiation Effects
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BERYLLIUM COMPOUNDS
BERYLLIUM OXIDES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHALCOGENIDES
CHARGED PARTICLES
DIFFUSION
HYDROGEN ISOTOPES
ION IMPLANTATION
IONS
ISOTOPES
LIGHT NUCLEI
NUCLEI
ODD-EVEN NUCLEI
OXIDES
OXYGEN COMPOUNDS
PERMEABILITY
RADIOISOTOPES
TRITIUM
TRITIUM IONS
YEARS LIVING RADIOISOTOPES