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Dive into the research topics where Michelle M. Valenta is active.

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Featured researches published by Michelle M. Valenta.


Archive | 2002

Characterization of Vadose Zone Sediment: Borehole 299-E33-45 Near BX-102 in the B-BX-BY Waste Management Area

R. Jeffrey Serne; Glendon W. Gee; Herbert T. Schaef; David C. Lanigan; Clark W. Lindenmeier; Michael J. Lindberg; Ray E. Clayton; Virginia L. Legore; Robert D. Orr; Igor V. Kutnyakov; Steven R. Baum; Keith N. Geiszler; Christopher F. Brown; Michelle M. Valenta

This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.22. The data was removed due to potential contamination introduced during the acid extraction process. The remaining text is unchanged from the original report issued in 2002. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area B-BX-BY. This report is the first in a series of four reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from borehole 299-E33-45 installed northeast of tank BX-102.


Archive | 2003

Characterization of Vadose Zone Sediment: RCRA Borehole 299-E33-338 Located Near the B-BX-BY Waste Management Area

Clark W. Lindenmeier; R. Jeffrey Serne; Bruce N. Bjornstad; Glendon W. Gee; Herbert T. Schaef; David C. Lanigan; Michael J. Lindberg; Ray E. Clayton; Virginia L. Legore; Igor V. Kutnyakov; Steven R. Baum; Keith N. Geiszler; Christopher F. Brown; Michelle M. Valenta; Lisa J. Royack

This report was revised in September 2008 to remove acid-extractable sodium data from Table 4.8. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in June 2003. The overall goals of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., are: 1) to define risks from past and future single-shell tank farm activities, 2) to identify and evaluate the efficacy of interim measures, and 3) to aid via collection of geotechnical information and data, future decisions that must be made by the U.S. Department of Energy (DOE) regarding the near-term operations, future waste retrieval, and final closure activities for the single-shell tank waste management areas. For a more complete discussion of the goals of the Tank Farm Vadose Zone Project, see the overall work plan, Phase 1 RCRA Facility Investigation/Corrective Measures Study Work Plan for the Single-Shell Tank Waste Management Areas (DOE 1999). Specific details on the rationale for activities performed at the B-BX-BY tank farm waste management area are found in CH2M HILL (2000).


Archive | 2008

Characterization of Vadose Zone Sediments Below the TX Tank Farm: Boreholes C3830, C3831, C3832 and RCRA Borehole 299-W10-27

R. Jeffrey Serne; Bruce N. Bjornstad; Duane G. Horton; David C. Lanigan; Clark W. Lindenmeier; Michael J. Lindberg; Ray E. Clayton; Virginia L. Legore; Robert D. Orr; Igor V. Kutnyakov; Steven R. Baum; Keith N. Geiszler; Michelle M. Valenta

This report was revised in September 2008 to remove acid-extractable sodium data from Tables 4.8, 4.28,4.43, and 4.59. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in April 2004. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area (WMA) T-TX-TY. This report is the first of two reports written to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from boreholes C3830, C3831, and C3832 in the TX Tank Farm, and from borehole 299-W-10-27 installed northeast of the TY Tank Farm.


Environmental Chemistry | 2007

Efficacy of soluble sodium tripolyphosphate amendments for the in-situ immobilisation of uranium

Dawn M. Wellman; Eric M. Pierce; Michelle M. Valenta

Environmental context. Contamination of groundwater and sediments by heavy metals and radioactive metals is a significant problem within the United States Department of Energy complex as a result of past nuclear operations. One way to remediate these metals is through reaction with phosphate compounds, which can immobilise the metals by forming highly stable metal phosphate compounds. Long-chain, water-soluble phosphate compounds provide a means to inject phosphate into subsurface contaminant plumes, to precipitate metal ions from solution. Results presented here illustrate that application of a soluble sodium tripolyphosphate to sediment contaminated with uranium will rapidly reduce the concentration of uranium in the pore water to concentrations near or below drinking water limits under water-saturated and unsaturated conditions. Abstract. A series of conventional water-saturated and pressurised unsaturated flow column experiments were conducted to evaluate the effects of using soluble polyphosphate amendments for in-situ, subsurface remediation of uranium. Experiments were conducted under mildly alkaline, calcareous conditions, representative of conditions commonly encountered at sites across the arid western United States. Results presented here illustrate that application of a soluble polyphosphate amendment to sediment contaminated with uranium will rapidly reduce the concentration of uranium released to the porewater to near or below drinking water limits under water-saturated and -unsaturated conditions. Column experiments conducted in the absence of polyphosphate illustrate sustained release of aqueous uranium at concentrations well above drinking water standards in excess of over 25 pore volumes under water-saturated conditions and over 50 pore volumes under unsaturated conditions. In the presence of tripolyphosphate, the concentration of aqueous uranium released from the sediment was below drinking water limits within 10 to 35 pore volumes under water-saturated and unsaturated conditions, respectively. Moreover, results indicate the necessity of conducting site-specific dynamic tests to tailor phosphate-based remediation technology to site specific geochemical and hydrological conditions.


Archive | 2011

Secondary Waste Form Development and Optimization—Cast Stone

S. K. Sundaram; Kent E. Parker; Michelle M. Valenta; Stan G. Pitman; Jaehun Chun; Chul-Woo Chung; Marcia L. Kimura; Carolyn A. Burns; Wooyong Um; Joseph H. Westsik

Washington River Protection Services is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF is a Resource Conservation and Recovery Act-permitted, multi-waste, treatment and storage unit and can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needs to be operational by 2018 to receive secondary liquid wastes generated during operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The STU to ETF will provide the additional capacity needed for ETF to process the increased volume of secondary wastes expected to be produced by WTP.


Archive | 2006

Characterization of Vadose Zone Sediments Below the C Tank Farm: Borehole C4297 and RCRA Borehole 299-E27-22

Christopher F. Brown; R. Jeffrey Serne; Bruce N. Bjornstad; Duane G. Horton; David C. Lanigan; Ray E. Clayton; Michelle M. Valenta; Igor V. Kutnyakov; Keith N. Geiszler; Steven R. Baum; Kent E. Parker; Michael J. Lindberg

The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc. tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within Waste Management Area (WMA) C. This report is the first of two reports written to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from borehole C4297, installed adjacent to Tank C-105, and from borehole 299-E27-22, installed directly north of the C Tank Farm. Sediments from borehole 299-E27-22 were considered to be background uncontaminated sediments against which to compare contaminated sediments for the C Tank Farm characterization effort. This report also presents our interpretation of the data in the context of sediment types, the vertical extent of contamination, the migration potential of the contaminants, and the likely source of the contamination in the vadose zone and groundwater below the C Tank Farm. The information presented in this report supports the A-AX, C and U Waste Management Area field investigation report(a) in preparation by CH2M HILL Hanford Group, Inc. A core log was generated for both boreholes and a geologic evaluation of all core samples was performed at the time of opening. Aliquots of sediment from the borehole core samples were analyzed and characterized in the laboratory for the following parameters: moisture content, gamma-emitting radionuclides, one-to-one water extracts (which provide soil pH, electrical conductivity, cation, trace metal, and anion data), total carbon and inorganic carbon content, and 8 M nitric acid extracts (which provide a measure of the total leachable sediment content of contaminants). Two key radiocontaminants, technetium-99 and uranium-238, along with other trace metals were determined in acid and water extracts by inductively coupled plasma mass spectrometry.


Archive | 2008

Characterization of Vadose Zone Sediment: Borehole 299-E33-46 Near B 110 in the B BX-BY Waste Management Area

R. Jeffrey Serne; Bruce N. Bjornstad; Glendon W. Gee; Herbert T. Schaef; David C. Lanigan; r. G. mccain; Clark W. Lindenmeier; Robert D. Orr; Virginia L. Legore; Ray E. Clayton; Michael J. Lindberg; I. V. Kutynakov; Steven R. Baum; Keith N. Geiszler; Michelle M. Valenta; Lisa J. Royack

This report was revised in September 2008 to remove acid-ectractable sodium data from Table 4.17. The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in December 2002. The overall goal of the of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities. To meet this goal, CH2M HILL Hanford Group, Inc., asked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediment from within the B-BX-BY Waste Management Area. This report is the third in a series of three reports to present the results of these analyses. Specifically, this report contains all the geologic, geochemical, and selected physical characterization data collected on vadose zone sediment recovered from a borehole installed approximately 4.5 m (15 ft) northeast of tank B- 110 (borehole 299-E33-46).


Archive | 2011

Secondary Waste Form Screening Test Results—THOR® Fluidized Bed Steam Reforming Product in a Geopolymer Matrix

Richard P. Pires; Joseph H. Westsik; R. Jeffrey Serne; Shas V. Mattigod; Elizabeth C. Golovich; Michelle M. Valenta; Kent E. Parker

Screening tests are being conducted to evaluate waste forms for immobilizing secondary liquid wastes from the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Plans are underway to add a stabilization treatment unit to the Effluent Treatment Facility to provide the needed capacity for treating these wastes from WTP. The current baseline is to use a Cast Stone cementitious waste form to solidify the wastes. Through a literature survey, DuraLith alkali-aluminosilicate geopolymer, fluidized-bed steam reformation (FBSR) granular product encapsulated in a geopolymer matrix, and a Ceramicrete phosphate-bonded ceramic were identified both as candidate waste forms and alternatives to the baseline. These waste forms have been shown to meet waste disposal acceptance criteria, including compressive strength and universal treatment standards for Resource Conservation and Recovery Act (RCRA) metals (as measured by the toxicity characteristic leaching procedure [TCLP]). Thus, these non-cementitious waste forms should also be acceptable for land disposal. Information is needed on all four waste forms with respect to their capability to minimize the release of technetium. Technetium is a radionuclide predicted to be in the secondary liquid wastes in small quantities, but the Integrated Disposal Facility (IDF) risk assessment analyses show that technetium, even at low mass, produces the largest contribution to the estimated IDF disposal impacts to groundwater.


Archive | 2009

Characterization of Sediments from the Soil Desiccation Pilot Test (SDPT) Site in the BC Cribs and Trenches Area

Wooyong Um; Michael J. Truex; Michelle M. Valenta; Cristian Iovin; Igor V. Kutnyakov; Hyun-Shik Chang; Ray E. Clayton; R. Jeffrey Serne; Anderson L. Ward; Christopher F. Brown; Keith N. Geiszler; Eric T. Clayton; Steven R. Baum; David M. Smith

This technical report documents the results of laboratory geochemical and hydrologic measurements of sediments collected from new borehole 299-E13-65 (C7047) and comparison of the results with those of nearby borehole 299-13E-62 (C5923) both drilled in the BC Cribs and Trenches Area. The total and water-leachable concentrations of key contaminants will be used to update contaminant-distribution conceptual models and to provide more data for improving baseline risk predictions and remedial alternative selections. Improved understanding of subsurface conditions and methods to remediate these principal contaminants can be also used to evaluate the application of specific technologies to other contaminants across the Hanford Site.


Archive | 2007

Characterization of Vadose Zone Sediments from C Waste Management Area: Investigation of the C-152 Transfer Line Leak

Christopher F. Brown; R. Jeffrey Serne; Bruce N. Bjornstad; Michelle M. Valenta; David C. Lanigan; Ray E. Clayton; Keith N. Geiszler; Cristian Iovin; Eric T. Clayton; I. V. Kutynakov; Steven R. Baum; Michael J. Lindberg; Robert D. Orr

The sodium data was removed due to potential contamination introduced during the acid extraction process. The rest of the text remains unchanged from the original report issued in January 2007. The overall goal of the Tank Farm Vadose Zone Project, led by CH2M HILL Hanford Group, Inc., is to define risks from past and future single-shell tank farm activities at Hanford. To meet this goal, CH2M HILL Hanford Group, Inc., tasked scientists from Pacific Northwest National Laboratory to perform detailed analyses on vadose zone sediments from within waste management area (WMA) C. Specifically, this report contains all the geologic, geochemical, and selected physiochemical characterization data compiled on vadose zone sediment recovered from direct-push samples collected around the site of an unplanned release (UPR), UPR-200-E-82, adjacent to the 241-C-152 Diversion Box located in WMA C.

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R. Jeffrey Serne

Pacific Northwest National Laboratory

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Keith N. Geiszler

Pacific Northwest National Laboratory

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Christopher F. Brown

Pacific Northwest National Laboratory

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Steven R. Baum

Pacific Northwest National Laboratory

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Igor V. Kutnyakov

Pacific Northwest National Laboratory

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Michael J. Lindberg

Office of Scientific and Technical Information

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Ray E. Clayton

Pacific Northwest National Laboratory

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Bruce N. Bjornstad

Pacific Northwest National Laboratory

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Herbert T. Schaef

Pacific Northwest National Laboratory

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Virginia L. Legore

Pacific Northwest National Laboratory

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