High-temperature leaching of an actinide-bearing, simulated high-level waste glass

Technical Report · Tue Mar 01 04:00:00 EST 1983

DOI:https://doi.org/10.2172/6494366· OSTI ID:6494366

Westsik, Jr, J H; Harvey, C O; Kuhn, W L

The chemical durability of a simulated high-level waste glass when exposed to high-temperature geologic solutions was investigated. In this study, simulated high-level waste glass-beads (76 to 68 glass)l doped with technetium, uranium, neptunium, plutonium, curium and americium were leached in deionized water, Waste Isolation Pilot Plant salt brine B, and 0.03M sodium bicarbonate solution at 150 and 250/sup 0/C for 2, 4, 8, 16, and 32 days. The resulting solutions were analyzed for several nonradioactive glass components and for the radioactive dopants. The glass exhibited incongruent leaching behavior, i.e., the normalized releases (g-glass/m/sup 2/) based on the different elements spanned four orders of magnitude. Normalized releases based on boron, molybdenum, sodium, cesium, silicon, and technetium were the same within a factor of three. Most of the nonradioactive components of the glass were released more to the salt brine than to the other two solutions. However, silicon, boron, molybdenum, technetium, and the actinides had their lowest releases in the salt brine. Reaction-layer thickness on the glass surface and weight losses of the glass beads were also smallest in the brine solution. Actinide releases were highest in the sodium bicarbonate solution. Calcium, strontium and barium releases decreased with time and temperature; the releases of most other elements increased with time and temperature. Solubility appears to be limiting the release of most elements. The leachate pH is controlled by chemical species within the original leachant and by species released as the glass leached. Carbonate ion complexes with some elements including uranium, effectively increasing their release. The more soluble elements including sodium, boron, molybdenum and technetium provide an indication of the actual rate of reaction between the glass and water.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6494366
• Report Number(s): PNL-3172; ON: DE83008755
• Country of Publication: United States
• Language: English

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
ACTINIDES
ALKALI METAL COMPOUNDS
ALKALI METALS
AMERICIUM
BORON
BRINES
CARBON COMPOUNDS
CARBONATES
CESIUM
CURIUM
DISSOLUTION
ELEMENTS
GEOLOGIC DEPOSITS
GLASS
HIGH-LEVEL RADIOACTIVE WASTES
HYDROGEN COMPOUNDS
LEACHING
MANAGEMENT
MATERIALS
METALS
MOLYBDENUM
NEPTUNIUM
OXYGEN COMPOUNDS
PLUTONIUM
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTES
SALT DEPOSITS
SEMIMETALS
SEPARATION PROCESSES
SILICON
SIMULATION
SODIUM
SODIUM CARBONATES
SODIUM COMPOUNDS
TECHNETIUM
TEMPERATURE EFFECTS
TRANSITION ELEMENTS
TRANSPLUTONIUM ELEMENTS
TRANSURANIUM ELEMENTS
UNDERGROUND DISPOSAL
URANIUM
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES
WATER