Diffusion of gases in solids: rare gas diffusion in solids; tritium diffusion in fission and fusion reactor metals. Final report

Technical Report · Wed Sep 01 04:00:00 EDT 1976

DOI:https://doi.org/10.2172/7251823· OSTI ID:7251823

Abraham, P M; Chandra, D; Mintz, J M; Elleman, T S; Verghese, K

Major results of tritium and rare gas diffusion research conducted under the contract are summarized. The materials studied were austenitic stainless steels, Zircaloy, and niobium. In all three of the metal systems investigated, tritium release rates were found to be inhibited by surface oxide films. The effective diffusion coefficients that control tritium release from surface films on Zircaloy and niobium were determined to be eight to ten orders of magnitude lower than the bulk diffusion coefficients. A rapid component of diffusion due to grain boundaries was identified in stainless steels. The grain boundary diffusion coefficient was determined to be about six orders of magnitude greater than the bulk diffusion coefficient for tritium in stainless steel. In Zircaloy clad fuel pins, the permeation rate of tritium through the cladding is rate-limited by the extremely slow diffusion rate in the surface films. Tritium diffusion rates through surface oxide films on niobium appear to be controlled by cracks in the surface films at temperatures up to 600/sup 0/C. Beyond 600/sup 0/C, the cracks appear to heal, thereby increasing the activation energy for diffusion through the oxide film. The steady-state diffusion of tritium in a fusion reactor blanket has been evaluated in order to calculate the equilibrium tritium transport rate, approximate time to equilibrium, and tritium inventory in various regions of the reactor blanket as a function of selected blanket parameters. Values for these quantities have been tabulated.

• Research Organization: North Carolina State Univ., Raleigh (USA). Dept. of Nuclear Engineering
• DOE Contract Number: E(40-1)-3508
• OSTI ID: 7251823
• Report Number(s): ORO-3508-10
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200 -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
360603 -- Materials-- Properties
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700209 -- Fusion Power Plant Technology-- Component Development & Materials Testing
ACTINIDE COMPOUNDS
ALLOYS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIBLIOGRAPHIES
CHALCOGENIDES
CHROMIUM ADDITIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
CORROSION RESISTANT ALLOYS
DAYS LIVING RADIOISOTOPES
DEFECTS
DIFFUSION
DOCUMENT TYPES
ELEMENTS
EVEN-ODD NUCLEI
FIRST WALL
FUEL CANS
HEAT RESISTING ALLOYS
HYDROGEN ISOTOPES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IRON ADDITIONS
IRON ALLOYS
IRON BASE ALLOYS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
METALS
NICKEL ALLOYS
NIOBIUM
NIOBIUM COMPOUNDS
NIOBIUM OXIDES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
OXIDES
OXYGEN COMPOUNDS
PERMEABILITY
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
RADIOISOTOPES
RARE GASES
REACTOR MATERIALS
REFRACTORY METALS
SEGREGATION
STAINLESS STEEL-304L
STAINLESS STEELS
STEELS
THERMONUCLEAR REACTOR MATERIALS
THERMONUCLEAR REACTOR WALLS
TIN ALLOYS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TRAPPING
TRITIUM
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES
XENON 133
XENON ISOTOPES
YEARS LIVING RADIOISOTOPES
ZIRCALOY
ZIRCALOY 2
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES