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Title: Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks

Abstract

This project, renewal of a previous EMSP project of the same title, is in its first year of funding at the University of Illinois at Chicago. The purpose is to continue investigating rates and mechanisms of reactions between primary sediment minerals found in the Hanford subsurface and leaked waste tank solutions. The goals are to understand processes that result in (1) changes in porosity and permeability of the sediment and resultant changes in flow paths of the contaminant plumes, (2) formation of secondary precipitates that can take up contaminants in their structures, and (3) release of mineral components that can drive redox reactions affecting dissolved contaminant mobility. A post-doctoral scientist, Dr. Sherry Samson, has been hired and two masters of science students are beginning to conduct experimental research. One research project that is underway is focused on measurement of the dissolution rates of plagioclase feldspar in high pH, high nitrate, high Al-bearing solutions characteristic of the BX tank farms. The first set of experiments is being conduced at room temperature. Subsequent experiments will examine the role of temperature because tank solutions in many cases were near boiling when leakage is thought to have occurred and temperature gradients have been observedmore » beneath the SX and BX tank farms. The dissolution experiments are being conducted in stirred-flow kinetic reactors using powdered labradorite feldspar from Pueblo Park, New Mexico.« less

Authors:
;
Publication Date:
Research Org.:
University of Illinois at Chicago, Chicago, IL (US)
Sponsoring Org.:
USDOE Office of Science (SC) (US)
OSTI Identifier:
839366
Report Number(s):
EMSP-86898-2003
R&D Project: EMSP 86898; TRN: US0501911
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 1 Jun 2003
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 54 ENVIRONMENTAL SCIENCES; ANORTHOSITES; BOILING; DISSOLUTION; FELDSPARS; KINETICS; PERMEABILITY; PLUMES; POROSITY; REDOX REACTIONS; SEDIMENTS; SOILS; STORAGE FACILITIES; TANKS; TEMPERATURE GRADIENTS; WASTES

Citation Formats

Nagy, Kathryn L., and Sturchio, Neil C. Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks. United States: N. p., 2003. Web. doi:10.2172/839366.
Nagy, Kathryn L., & Sturchio, Neil C. Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks. United States. doi:10.2172/839366.
Nagy, Kathryn L., and Sturchio, Neil C. Sun . "Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks". United States. doi:10.2172/839366. https://www.osti.gov/servlets/purl/839366.
@article{osti_839366,
title = {Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks},
author = {Nagy, Kathryn L. and Sturchio, Neil C.},
abstractNote = {This project, renewal of a previous EMSP project of the same title, is in its first year of funding at the University of Illinois at Chicago. The purpose is to continue investigating rates and mechanisms of reactions between primary sediment minerals found in the Hanford subsurface and leaked waste tank solutions. The goals are to understand processes that result in (1) changes in porosity and permeability of the sediment and resultant changes in flow paths of the contaminant plumes, (2) formation of secondary precipitates that can take up contaminants in their structures, and (3) release of mineral components that can drive redox reactions affecting dissolved contaminant mobility. A post-doctoral scientist, Dr. Sherry Samson, has been hired and two masters of science students are beginning to conduct experimental research. One research project that is underway is focused on measurement of the dissolution rates of plagioclase feldspar in high pH, high nitrate, high Al-bearing solutions characteristic of the BX tank farms. The first set of experiments is being conduced at room temperature. Subsequent experiments will examine the role of temperature because tank solutions in many cases were near boiling when leakage is thought to have occurred and temperature gradients have been observed beneath the SX and BX tank farms. The dissolution experiments are being conducted in stirred-flow kinetic reactors using powdered labradorite feldspar from Pueblo Park, New Mexico.},
doi = {10.2172/839366},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jun 01 00:00:00 EDT 2003},
month = {Sun Jun 01 00:00:00 EDT 2003}
}

Technical Report:

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  • Since the late 1950s, leaks from 67 single-shell tanks at the Hanford Site have released about 1 million curies to the underlying sediments. At issue is the distribution of contaminants beneath the tanks, and the processes that led to their current disposition and will control their future mobility. The high ionic strength, high pH, and high aluminum concentrations in the tank liquids can significantly alter the vadose zone sediments through dissolution of primary minerals and precipitation of secondary minerals. Dissolution and precipitation directly influence (1) the flow paths that control contaminant transport and (2) the reactivity of the solid matrixmore » that controls contaminant mobility. The impact of these processes, however, depends on mineral reaction kinetics and the dynamic interaction of the reactions with the flow field and contaminant sorption, neither of which are well-known for this extreme chemical system. Data obtained will be directly useful to other EMSP projects addressing contaminant mobility in the vadose zone. We are addressing three specific issues: (1) Recognized factors that control the kinetics of dissolution and precipitation must be quantified for the unnatural system of tank solutions mixing with soils, including effects of high pH, high ionic strength (especially NaNO3 solutions), temperature, and saturation state. (2) A clear understanding of the roles of nucleation mechanism, nucleation sites on soils minerals, and the role of reactive surface area in simultaneous dissolution and precipitation reactions are the key unknown components in comprehending this contaminated soil system. (3) Results obtained will help build a mechanistic understanding of how tank fluids migrate through the vadose zone. Local changes in porosity and permeability will dictate preferential flow paths which directly regulate the transport of later arriving chemical species. Changes in mineral surface area affect sorption site distribution. A comprehensive model is needed that integrates these feedback mechanisms with all the critically available data.« less
  • Objective: The primary goals of this project are to (1) quantify the kinetics and thermodynamics of dominant mineral dissolution and precipitation reactions considered to result in significant uptake of contaminants upon mixing of leaked tank fluids and Hanford soil and soil solutions; (2) quantify the kinetics of subsequent reactions that might enhance the mobility of the contaminants; and, (3) quantify the uptake of radionuclide contaminants in the secondary precipitates.
  • The purpose of the project was to investigate rates and mechanisms of reactions between primary sediment minerals and key components of waste tank solutions that leaked into the subsurface at the Hanford Site. Results were expected to enhance understanding of processes that cause (1) changes in porosity and permeability of the sediment and resultant changes in flow paths of the contaminant plumes, (2) formation of secondary precipitates that can take up contaminants in their structures, and (3) release of mineral components that can drive redox reactions affecting dissolved contaminant mobility. Measured rates can also be used directly in reactive transportmore » models. Project tasks included (1) measurement of the dissolution rates of biotite mica from low to high pH and over a range of temperature relevant to the Hanford subsurface, (2) measurement of dissolution rates of quartz at high pH and in the presence of dissolved alumina, (3) measurement of the dissolution rates of plagioclase feldspar in high pH, high nitrate, high Al-bearing solutions characteristic of the BX tank farms, (4) incorporation of perrhenate in iron-oxide minerals as a function of pH, and (5) initiation of experiments to measure the formation of uranium(VI)-silicate phases under ambient conditions. Task 2 was started under a previous grant from the Environmental Management Science Program and Task 4 was partially supported by a grant to the PI from the Geosciences Program, Office of Basic Energy Sciences. Task 5 was continued under a subsequent grant from the Environmental Remediation Sciences Program, Office of Biological and Environmental Research.« less
  • The 241-SY-101 tank is a double-shell waste storage tank buried in the 241-SY tank farm in the 200 West Area of the Hanford Site. This analysis addresses the effects of seismic soil-structure interaction on the tank structure and includes a parametric soil-structure interaction study addressing three configurations: two-dimensional soil structure, a two-dimensional structure-soil-structure, and a three-dimensional soil-structure interaction. This study was designed to determine an optimal method for addressing seismic-soil effects on underground storage tanks. The computer programs calculate seismic-soil pressures on the double-steel tank walls and seismic acceleration response spectra in the tank. The results of this soil-structure interactionmore » parametric study as produced by the computer programs are given in terms of seismic soil pressures and response spectra. The conclusions of this soil-structure interaction evaluation are that dynamically calculated soil pressures in the 241-SY-101 tank are significantly reduced from those using standard hand calculation methods and that seismic evaluation of underground double-shell waste storage tanks must consider soil-structure interaction effects in order to predict conservative structural response. Appendixes supporting this study are available in Volume 2 of this report.« less
  • The 241-SY-101 tank is a double-shell waste storage tank buried in the 241-SY tank farm in the 200 West Area of the Hanford Site. This analysis addresses the effects of seismic soil-structure interaction on the tank structure and includes a parametric soil-structure interaction study addressing three configurations: two-dimensional soil structure, a two-dimensional structure-soil-structure, and a three-dimensional soil-structure interaction. This study was designed to determine an optimal method for addressing seismic-soil effects on underground storage tanks. The computer programs calculate seismic-soil pressures on the double-shell tank walls and and seismic acceleration response spectra in the tank. The results of this soil-structuremore » interaction parametric study as produced by the computer programs are given in terms of seismic soil pressures and response spectra. The conclusions of this soil-structure interaction evaluation are that dynamically calculated soil pressures in the 241-SY-101 tank are significantly reduce from those using standard hand calculation methods and that seismic evaluation of underground double-shell waste storage tanks must consider soil-structure interaction effects in order to predict conservative structural response. Appendixes supporting this study are available in Volume 2 of this report.« less