Processing, microstructure, leaching, and long-term stability studies related to titanate high-level waste forms

Technical Report · Sun May 01 04:00:00 EDT 1983

OSTI ID:6012076

Dosch, R G; Headley, T J; Northrup, C J; Hlava, P F

A process leading to titanate-based waste forms for commercial high-level nuclear waste is described. Radionuclides are fixed on hydrous calcium titanate by ion exchange/sorption reactions and the material is converted to a dense, ceramic form by hot pressing. Transmission electron microscopy-electron microprobe characterization was done to determine the effects of compositional changes and process variations on microstructure. Leaching studies in the range of 22 to 150/sup 0/C and pH 2 to 12 were done to assess the effects of the same variables on leaching behavior. Samples of a reference borosilicate glass waste form were leached under the same conditions to provide a direct comparison between the two waste forms. Lead-ion implantation was used to simulate long-term ..cap alpha..-recoil damage in the crystalline titanate phases. Comparison of ..cap alpha..-recoil damage in natural minerals with damage induced in synthesized samples of the same mineral suggest that Pb-ion implantation is a valid technique for simulating ..cap alpha..-recoil effects. All the titanate phases sustained significant lattice damage at equivalent ..cap alpha..-doses of 1 x 10/sup 19//cm/sup 3/; however, Rutherford backscattering and transmission electron microscopy studies showed that the damage did not result in significant matrix dissolution in these leaching tests.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6012076
• Report Number(s): SAND-82-2980; ON: DE83015637
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360205 -- Ceramics
Cermets
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ACTINIDES
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
BARIUM
CALCIUM
CALCIUM COMPOUNDS
CRYSTAL STRUCTURE
DISSOLUTION
ELEMENTS
FABRICATION
GADOLINIUM
GADOLINIUM COMPOUNDS
HIGH-LEVEL RADIOACTIVE WASTES
HOT PRESSING
ION EXCHANGE
ION EXCHANGE MATERIALS
LEACHING
MANAGEMENT
MATERIALS
MATERIALS WORKING
MATRIX MATERIALS
METALS
MICROSTRUCTURE
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
PRESSING
PROCESSING
RADIATION EFFECTS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTES
RARE EARTH COMPOUNDS
RARE EARTHS
RECOILS
SEPARATION PROCESSES
SOLIDIFICATION
STABILITY
STRONTIUM
TITANATES
TITANIUM
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
URANIUM
WASTE MANAGEMENT
WASTE PROCESSING
WASTES