Estimates of the solubilities of waste element radionuclides in waste isolation pilot plant brines: A report by the expert panel on the source term
- Sandia National Labs., Albuquerque, NM (United States)
Evaluation of the long-term performance of the WIPP includes estimation of the cumulative releases of radionuclide elements to the accessible environment. Nonradioactive lead is added because of the large quantity expected in WIPP wastes. To estimate the solubilities of these elements in WIPP brines, the Panel used the following approach. Existing thermodynamic data were used to identify the most likely aqueous species in solution through the construction of aqueous speciation diagrams. Existing thermodynamic data and expert judgment were used to identify potential solubility-limiting solid phases. Thermodynamic data were used to calculate the activities of the radionuclide aqueous species in equilibrium with each solid. Activity coefficients of the radionuclide-bearing aqueous species were estimated using Pitzer`s equations. These activity coefficients were then used to calculate the concentration of each radionuclide at the 0.1 and 0.9 fractiles. The 0.5 fractile was chosen to represent experimental data with activity coefficient corrections as described above. Expert judgment was used to develop the 0.0, 0.25, 0.75, and 1.0 fractiles by considering the sensitivity of solubility to the potential variability in the composition of brine and gas, and the extent of waste contaminants, and extending the probability distributions accordingly. The results were used in the 1991 and 1992 performance assessment calculations. 68 refs.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 373829
- Report Number(s):
- SAND-96-0098; ON: DE96014899; TRN: 96:025621
- Resource Relation:
- Other Information: PBD: May 1996
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
WIPP
SOURCE TERMS
RADIOISOTOPES
SOLUBILITY
PERFORMANCE
SAFETY ANALYSIS
RADIONUCLIDE MIGRATION
FORECASTING
BRINES
WATER CHEMISTRY
ALPHA-BEARING WASTES
RADIOACTIVE WASTE DISPOSAL
RADIUM
THORIUM
URANIUM
NEPTUNIUM
PLUTONIUM
AMERICIUM
CURIUM
LEAD
THERMODYNAMIC PROPERTIES
PHASE STUDIES
CONCENTRATION RATIO
PROBABILISTIC ESTIMATION
CALCULATION METHODS
EVALUATED DATA