Thermodynamic modeling of neptunium(V) solubility in concentrated Na-CO3-HCO3-Cl-ClO4-H-OH-H2O systems
Creators
- 1. Sandia National Labs., Albuquerque, NM (United States)
- 2. Lawrence Berkeley Lab., CA (United States)
Description
Safety assessments of nuclear waste repositories often require estimation of actinide solubilities as a function of groundwater composition. Although considerable amount of research has been done on the solubility and speciation of actinides, relatively little has been done to unify these data into a model applicable to concentrate brines. Numerous authors report data on the aqueous chemical properties of Np(V) in NaClO4, Na2CO3, and NaCl media, but a consistent thermodynamic model for predicting these properties is not available. To meet this need, a model was developed to describe the solubility of Np(V) in Na-Cl-ClO4-CO3 aqueous systems, based on the Pitzer activity coefficient formalism for concentrated electrolytes. Hydrolysis and/or carbonate complexation are the dominant aqueous reactions with neptunyl in these systems. Literature data for neptunyl extraction and solubility, and solubility data that the authors developed, are used to parameterize an integrated model for Np(V) solubility in the Np(V)-Na-CO3-HCO3-Cl-ClO4-H-OH-H2O system. The resulting model is tested against additional solubility data, and compared with Np(V) solubility experiments in complex synthetic brines
Availability note (English)
MF available from INIS under the Report Number; Also available from OSTI as DE95001605; NTIS; US Govt. Printing Office Dep.Files
26026668.pdf
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Additional details
Publishing Information
- Imprint Pagination
- 11 p.
- Report number
- SAND--94-0805C
Conference
- Title
- 18. international symposium on the scientific basis for nuclear waste management.
- Dates
- 23-27 Oct 1994.
- Place
- Kyoto (Japan).
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 26026668
- Subject category
- S12: MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; S54: ENVIRONMENTAL SCIENCES;
- Resource subtype / Literary indicator
- Conference, Numerical Data
- Descriptors DEI
- CHLORATES; ENVIRONMENTAL TRANSPORT; EXPERIMENTAL DATA; GROUND WATER; MATHEMATICAL MODELS; NEPTUNIUM COMPOUNDS; RADIOACTIVE WASTE DISPOSAL; SODIUM CARBONATES; SODIUM CHLORIDES; SODIUM COMPOUNDS; SODIUM HYDRIDES; SODIUM HYDROXIDES; SOLUBILITY; SOLVENT PROPERTIES; THERMODYNAMIC PROPERTIES; UNDERGROUND DISPOSAL
- Descriptors DEC
- ACTINIDE COMPOUNDS; ALKALI METAL COMPOUNDS; CARBON COMPOUNDS; CARBONATES; CHLORIDES; CHLORINE COMPOUNDS; DATA; HALIDES; HALOGEN COMPOUNDS; HYDRIDES; HYDROGEN COMPOUNDS; HYDROXIDES; INFORMATION; MANAGEMENT; MASS TRANSFER; NUMERICAL DATA; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; TRANSURANIUM COMPOUNDS; WASTE DISPOSAL; WASTE MANAGEMENT; WATER
Optional Information
- Contract/Grant/Project number
- Contract AC04-94AL85000
- Funding organization
- USDOE, Washington, DC (United States).
- Secondary number(s)
- CONF-941075--2.