Synroc technology for immobilizing U. S. defense waste
Synroc technology has been applied to immobilize U.S. defense high level wastes similar to those stored at the Savannah River Plant (SRP). Titanate-based ceramic waste-form specimens (Synroc D), containing simulated SRP sludge of average composition, were synthesized by conventional hot-pressing techniques. The waste-form specimens were characterized by x-ray diffraction and scanning electron microscopy, and their stability assessed by leaching methods. Major phases present are zinconolite, perovskite, spinel solid solution, nepheline, and a Cs-hollandite analog, prepared separately and added to the calcined powder before densification. Normalized single-day static leach rates for the major matrix elements in Synroc D using deionized water at 150/sup 0/C are in the range 10/sup -2/ -10/sup -5/ g/m/sup 2/day. Static leach rates for cesium were 1.85 g/m/sup 2/day on the first day, decreasing to 1.7x10/sup -1/ b/m/sup 2/day after the third day. Dynamic leach rates for cesium in the Synroc-D waste form and in the (Ba,Cs)-hollandite analog material using deionized water at 75/sup 0/C were 5x10/sup -1/ g Synroc D/m/sup 2/day on the first day, decreasing to 1.2x10/sup -2/ g Synroc D/m/sup 2/day after the 12th day, and 1x10/sup -1/g(Ba,Cs)-hollandite/m/sup 2/day on the first day, decreasing to 5x10/sup -4/ g (Ba,Cs)-hollandite/m/sup 2/day after 44 days, respectively. 45 refs.
- Research Organization:
- Lawrence Livermore Natl Lab, CA, USA
- OSTI ID:
- 6348677
- Journal Information:
- Am. Ceram. Soc. Bull.; (United States), Journal Name: Am. Ceram. Soc. Bull.; (United States) Vol. 61:5; ISSN ACSBA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
052002 -- Nuclear Fuels-- Waste Disposal & Storage
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
360604 -- Materials-- Corrosion
Erosion
& Degradation
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BARIUM COMPOUNDS
BARIUM OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
DIFFRACTION
DISSOLUTION
ELECTRON MICROSCOPY
HIGH-LEVEL RADIOACTIVE WASTES
HOLLANDITE
LEACHING
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MANAGEMENT
MATERIALS
MICROSCOPY
MINERALS
NORTH AMERICA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITE
PEROVSKITES
PHASE TRANSFORMATIONS
PROCESSING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTES
ROCKS
SCANNING ELECTRON MICROSCOPY
SCATTERING
SEPARATION PROCESSES
SOLIDIFICATION
SPINELS
SYNROC PROCESS
SYNTHETIC MATERIALS
SYNTHETIC ROCKS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
USA
WASTE DISPOSAL
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
X-RAY DIFFRACTION