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In situ construction of horizontal soil containment barrier at Fernald

Description: An innovative method of placing soil barriers to contain vertical flow is being prepared for demonstration by the Fernald Environmental Restoration Management Corporation (FERMCO), working in conjunction with the Department of Energy Office of Technology Development (DOE/OTD) and two principle subcontractors. The method employs proven directional drilling techniques, jet grouting technology and unique placement tooling to form horizontal soil barriers in situ. This is done without disturbance to existing land disposed wastes. This paper is a summary report on the current state of that demonstration, including: a discussion of the construction methods, the results of the initial tool tests, an overview of the Fernald site conditions and, the resulting path of tooling development for the second phase of tool testing.
Date: April 1, 1995
Creator: Ridenour, D.; Pettit, P.J. & Walker, J.
Partner: UNT Libraries Government Documents Department

Pressure grouting of fractured basalt flows

Description: This report describes a field trial of pressure grouting in basalt and the results of subsequent coring and permeability measurement activities. The objective was to show that the hydraulic conductivity of fractured basalt bedrock can be significantly reduced by pressure injection of cementitious materials. The effectiveness of the pressure grout procedure was evaluated by measuring the change in the hydraulic conductivity of the bedrock. The extent of grout penetration was established by analyzing postgrout injection drilling chips for the presence of a tracer in the grout and also by examining cores of the treated basalt. Downhole radar mapping was used to establish major lava flow patterns and follow water movement during a surface infiltration test. A site called Box Canyon, which is located northwest of the INEL, was chosen for this study due to the similarity of this surface outcrop geology to that of the underlying bedrock fracture system found at the Radioactive Waste Management Complex. This study showed that hydraulic conductivity of basalt can be reduced through pressure grouting of cementitious material.
Date: April 1, 1996
Creator: Shaw, P.; Weidner, J.; Phillips, S. & Alexander, J.
Partner: UNT Libraries Government Documents Department

A new and superior ultrafine cementitious grout

Description: Sealing fractures in nuclear waste repositories concerns all programs investigating deep burial as a means of disposal. Because the most likely mechanism for contaminant migration is by dissolution and movement through groundwater, sealing programs are seeking low-viscosity sealants that are chemically, mineralogically, and physically compatible with the host rock. This paper presents the results of collaborative work directed by Sandia National Laboratories (SNL) and supported by Whiteshell Laboratories, operated by Atomic Energy of Canada, Ltd. The work was undertaken in support of the Waste Isolation Pilot Plant (WIPP), an underground nuclear waste repository located in a salt formation east of Carlsbad, NM. This effort addresses the technology associated with long-term isolation of nuclear waste in a natural salt medium. The work presented is part of the WIPP plugging and sealing program, specifically the development and optimization of an ultrafine cementitious grout that can be injected to lower excessive, strain-induced hydraulic conductivity in the fractured rock termed the Disturbed Rock Zone (DRZ) surrounding underground excavations. Innovative equipment and procedures employed in the laboratory produced a usable cement-based grout; 90% of the particles were smaller than 8 microns and the average particle size was 4 microns. The process involved simultaneous wet pulverization and mixing. The grout was used for a successful in situ test underground at the WIPP. Injection of grout sealed microfractures as small as 6 microns (and in one rare instance, 3 microns) and lowered the gas transmissivity of the DRZ by up to three orders of magnitude. Following the WIPP test, additional work produced an improved version of the grout containing particles 90% smaller than 5 microns and averaging 2 microns. This grout will be produced in dry form, ready for the mixer.
Date: April 1, 1997
Creator: Ahrens, E.H.
Partner: UNT Libraries Government Documents Department

Remediation options for a chromium contaminated landfill using cementitious grouts

Description: In-situ remediation of a chemical waste landfill with excessive chromium levels is being investigated as part of the Mixed Waste Landfill Integrated Demonstration. This paper is concerned with the design of advanced cementitious grouts for in-situ stabilization of chromium contaminated soil and in-situ installation of subsurface containment barriers. Grouts have been developed to improve the performance and cost effectiveness of remediation compared with conventional materials. In addition to restoration of chromium contaminated soils, the developed grouts have applications in other environmental operations where superior properties are required.
Date: April 1, 1995
Creator: Allan, M.L. & Kukacka, L.E.
Partner: UNT Libraries Government Documents Department

Fiscal year 1996 well plugging and abandonment program Y-12 Plant, Oak Ridge, Tennessee

Description: This report is a synopsis of the progress of the well plugging and abandonment program at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee, from August 1995 through August 1996. A total of 27 wells, piezometers, and borings were plugged and abandoned during the period of time covered in this report. All wells and borings were plugged and abandoned in accordance with the Monitoring Well Plugging and Abandonment Plan for the U.S. Department of Energy, Y-12 Plant, Oak Ridge, Tennessee (HSW, Inc. 1991).
Date: April 1, 1997
Partner: UNT Libraries Government Documents Department

Tank closure reducing grout

Description: A reducing grout has been developed for closing high level waste tanks at the Savannah River Site in Aiken, South Carolina. The grout has a low redox potential, which minimizes the mobility of Sr{sup 90}, the radionuclide with the highest dose potential after closure. The grout also has a high pH which reduces the solubility of the plutonium isotopes. The grout has a high compressive strength and low permeability, which enhances its ability to limit the migration of contaminants after closure. The grout was designed and tested by Construction Technology Laboratories, Inc. Placement methods were developed by the Savannah River Site personnel.
Date: April 18, 1997
Creator: Caldwell, T. B.
Partner: UNT Libraries Government Documents Department

Grout performance in support of in situ grouting of the TH4 tank sludge

Description: The cold demonstration test proved that less water was required to pump the in situ grout formulation than had been previously tested in the laboratory. The previous in situ grout formulation was restandardized with the same relative amounts of dry blend ingredients, albeit adding a fluidized admixture, but specifying less water for the slurry mix that must by pumped through the nozzles at high pressure. Also, the target GAAT tank for demonstrating this is situ grouting technique has been shifted to Tank TH4. A chemical surrogate sludge for TH4 was developed and tested in the laboratory, meeting expectations for leach resistance and strenght at 35 wt % sludge loading. It addition, a sample of hot TH4 sludge was also tested at 35 wt % sludge loading and proved to have superior strength and leach resistance compared with the surrogate test.
Date: April 1999
Creator: Hunt, R. D.; Kauschinger, J. L. & Spence, R. D.
Partner: UNT Libraries Government Documents Department

Treatability study Number PDC-1-O-T. Final report

Description: Los Alamos National Laboratory provided treatability study samples from four waste streams, designated Stream {number_sign}1, Stream {number_sign}3, Stream {number_sign}6, and Stream {number_sign}7. Stream {number_sign}1 consisted of one 55-gallon drum of personal protective equipment (PPE), rags, and neutralizing agent (bicarbonate) generated during the cleanup of a sodium dichromate solution spill. Stream {number_sign}3 was one 55-gallon drum of paper, rags, lab utensils, tools, and tape from the decontamination of a glovebox. The sample of Stream {number_sign}6 was packaged in three 30-gallon drums and a 100 ft{sup 3} wooden box. It consisted of plastic sheeting, PPE, and paper generated from the cleanup of mock explosive (barium nitrate) from depleted uranium parts. Stream {number_sign}7 was scrap metal (copper, stainless and carbon steel joined with silver solder) from the disassembly of gas manifolds. The objective of the treatability study is to determine: (1) whether the Perma-Fix stabilization/solidification process can treat the waste sample to meet Land Disposal Restrictions and the Waste Acceptance Criteria for LANL Technical Area 54, Area G, and (2) optimum loading and resulting weight and volume of finished waste form. The stabilized waste was mixed into grout that had been poured into a lined drum. After each original container of waste was processed, the liner was closed and a new liner was placed in the same drum on top of the previous closed liner. This allowed an overall reduction in waste volume but kept waste segregated to minimize the amount of rework in case analytical results indicated any batch did not meet treatment standards. Samples of treated waste from each waste stream were analyzed by Perma-Fix Analytical Services to get a preliminary approximation of TCLP metals. Splits of these samples were sent to American Environmental Network`s mixed waste analytical lab in Cary, NC for confirmation analysis. Results were all below applicable limits.
Date: April 22, 1998
Partner: UNT Libraries Government Documents Department

Early containment of high-alkaline solution simulating low-level radioactive waste stream in clay-bearing blended cement

Description: Portland cement blended with fly ash and attapulgite clay was mixed with high-alkaline solution simulating low-level radioactive waste stream at a one-to-one weight ratio. Mixtures were adiabatically and isothermally cured at various temperatures and analyzed for phase composition, total alkalinity, pore solution chemistry, and transport properties as measured by impedance spectroscopy. Total alkalinity is characterized by two main drops. The early one corresponds to a rapid removal of phosphorous, aluminum, sodium, and to a lesser extent potassium solution. The second drop from about 10 h to 3 days is mainly associated with the removal of aluminum, silicon, and sodium. Thereafter, the total alkalinity continues descending, but at a lower rate. All pastes display a rapid flow loss that is attributed to an early precipitation of hydrated products. Hemicarbonate appears as early as one hour after mixing and is probably followed by apatite precipitation. However, the former is unstable and decomposes at a rate that is inversely related to the curing temperature. At high temperatures, zeolite appears at about 10 h after mixing. At 30 days, the stabilized crystalline composition Includes zeolite, apatite and other minor amounts of CaCO{sub 3}, quartz, and monosulfate Impedance spectra conform with the chemical and mineralogical data. The normalized conductivity of the pastes shows an early drop, which is followed by a main decrease from about 12 h to three days. At three days, the permeability of the cement-based waste as calculated by Katz-Thompson equation is over three orders of magnitude lower than that of ordinary portland cement paste. However, a further decrease in the calculated permeability is questionable. Chemical stabilization is favorable through incorporation of waste species into apatite and zeolite.
Date: April 1, 1995
Creator: Kruger, A.A.; Olson, R.A. & Tennis, P.D.
Partner: UNT Libraries Government Documents Department

Process modeling for the Integrated Nonthermal Treatment System (INTS) study

Description: This report describes the process modeling done in support of the Integrated Nonthermal Treatment System (INTS) study. This study was performed to supplement the Integrated Thermal Treatment System (ITTS) study and comprises five conceptual treatment systems that treat DOE contract-handled mixed low-level wastes (MLLW) at temperatures of less than 350{degrees}F. ASPEN PLUS, a chemical process simulator, was used to model the systems. Nonthermal treatment systems were developed as part of the INTS study and include sufficient processing steps to treat the entire inventory of MLLW. The final result of the modeling is a process flowsheet with a detailed mass and energy balance. In contrast to the ITTS study, which modeled only the main treatment system, the INTS study modeled each of the various processing steps with ASPEN PLUS, release 9.1-1. Trace constituents, such as radionuclides and minor pollutant species, were not included in the calculations.
Date: April 1, 1997
Creator: Brown, B.W.
Partner: UNT Libraries Government Documents Department

Sludge displacement verification for reducing grout report

Description: To support the closure of HLW tanks at SRS, a reducing grout was developed that is formulated to reduce the mobility of radionuclides left in each tank. During non-radioactive flow tests of the grout, it was discovered that, in addition to its desired properties, the grout has the ability to move residual waste a considerable distance across the tank floor.
Date: April 10, 1997
Creator: Caldwell, T. B. & Langton, C. A.
Partner: UNT Libraries Government Documents Department

GEOTHERMAL HEAT PUMP GROUTING MATERIALS

Description: The thermal conductivity of cementitious grouts has been investigated in order to determine suitability of these materials for grouting vertical boreholes used with geothermal heat pumps. The roles of mix variables such as water/cement ratio, sand/cement ratio and superplasticizer dosage were measured. The cement-sand grouts were also tested for rheological characteristics, bleeding, permeability, bond to HDPE pipe, shrinkage, coefficient of thermal expansion, exotherm, durability and environmental impact. This paper summarizes the thermal conductivity, permeability, bonding and exotherm data for selected cementitious grouts. The theoretical reduction in bore length that could be achieved with the BNL-developed cement-sand grouts is examined. Finally, the FY 98 research and field trials are discussed.
Date: April 1, 1998
Creator: ALLAN,M.
Partner: UNT Libraries Government Documents Department

Code requirements for concrete repository and processing facilities

Description: The design and construction of facilities and structures for the processing and safe long-term storage of low- and high-level radioactive wastes will likely employ structural concrete. This concrete will be used for many purposes including structural support, shielding, and environmental protection. At the present time, there are no design costs, standards or guidelines for repositories, waste containers, or processing facilities. Recently, the design and construction guidelines contained in American Concrete Institute (ACI), Code Requirements for Nuclear Safety Related Concrete Structures (ACI 349), have been cited for low-level waste (LLW) repositories. Conceptual design of various high-level (HLW) repository surface structures have also cited the ACI 349 Code. However, the present Code was developed for nuclear power generating facilities and its application to radioactive waste repositories was not intended. For low and medium level radioactive wastes, concrete has a greater role and use in processing facilities, engineered barriers, and repository structures. Because of varied uses and performance/safety requirements this review of the current ACI 349 Code document was required to accommodate these special classes of structures.
Date: April 1, 1993
Creator: Hookham, C. J. & Palaniswamy, R.
Partner: UNT Libraries Government Documents Department

The Hybrid Treatment Process for treatment of mixed radioactive and hazardous wastes

Description: This paper describes a new process for treating mixed hazardous and radioactive waste, commonly called mixed waste. The process is called the Hybrid Treatment Process (HTP), so named because it is built on the 20 years of experience with vitrification of wastes in melters, and the 12 years of experience with treatment of wastes by the in situ vitrification (ISV) process.
Date: April 1, 1992
Creator: Ross, W. A. & Kindle, C. H.
Partner: UNT Libraries Government Documents Department

Determination of the biodegradation rate of asphalt for the Hanford grout vaults. Hanford Grout Technology Program

Description: Testing was initiated in March 1991 and completed in November 1992 to determine the rate at which asphalt is biodegraded by microorganisms native to the Hanford Site soils. The asphalt tested (AR-6000, US Oil, Tacoma, Washington) is to be used in the construction of a diffusion barrier for the Hanford grout vaults. Experiments to determine asphalt biodegradation rates were conducted using three separate test sets. These test sets were initiated in March 1991, January 1992, and June 1992 and ran for periods of 6 months, 11 months, and 6 months, respectively. The experimental method used was one originally developed by Bartha and Pramer (1965), and further refined by Bowerman et al. (1985), that determined the asphalt biodegradation rate through the measurement of carbon dioxide evolved.
Date: April 1, 1993
Creator: Luey, J. & Li, S. W.
Partner: UNT Libraries Government Documents Department

Leach testing of in situ stabilization grouts containing additives to sequester contaminants

Description: This document discusses laboratory testing performed by Pacific Northwest Laboratory (PNL) for Westinghouse Hanford Company (WHC) of special grout formulations that incorporate specific sequestering agents to help improve the ability of the cement to resist contaminant leaching. To enhance the sequestering of contaminants we chose five additives to introduce (singly) to the control cement. The additives were Florida pebble phosphate, clinoptilolite (a natural zeolite), ferrous sulfide (a reductant), a mixed bed organic ion exchange resin and a proprietary anion-adsorbing mixed metal oxide. These additives were added one per test to the standard formulation and used to encapsulate a diluted high-salt alkaline liquid waste that is produced after various processes to remove uranium and plutonium from spent nuclear fuel. This report documents the testing of these additives.
Date: April 1, 1993
Creator: Serne, R. J.; Ames, L. L.; Martin, P. F. C.; LeGore, V. L.; Lindenmeier, C. W. & Phillips, S. J.
Partner: UNT Libraries Government Documents Department

Feasibility of permeation grouting for constructing subsurface barriers

Description: Efforts are being made to devise technologies that provide interim containment of waste sites while final remediation alternatives are developed. Permeation grouting, a technique used extensively in the civil and mining engineering industry has been investigated as a method for emplacing a subsurface containment barrier beneath existing waste sites. Conceptually an underlying barrier is placed by injecting grout into the formation at less than fracturing pressure from a series of directionally drilled boreholes beneath the waste site. This study evaluated the penetration and performance characteristics in varying soil conditions of four different grout materials (two microfine cements, mineral wax, and sodium silicate) at a field scale. Field testing consisted of grout injection via sleeve (tube-a`-manchette) pipe into both vertical and horizontal borehole configurations at the Mixed Waste Landfill Integrated Demonstration site at Sandia National Laboratories. Prior to, during, and after grout injection non-intrusive geophysical techniques were used to map grout flow. Following the tests, the site was excavated to reveal details of the grout permeation, and grouted soil samples were cored for laboratory characterization. The non-intrusive and intrusive grout mapping showed preferential flow patterns, i.e., the grout tended to follow the path of least resistance. Preliminary testing indicates that permeation grouting is a feasible method for emplacing a low permeability subsurface barrier in the semi-arid unconsolidated alluvial soils common to the Southwest. Despite the success of this project, difficulties in predicting grout flow in heterogeneous soils and non-intrusive methods for imaging grout location and continuity are issues that need more attention.
Date: April 1, 1994
Creator: Dwyer, B. P.
Partner: UNT Libraries Government Documents Department

Polyethylene encapsulation of single shell tank low-level wastes

Description: Polyethylene encapsulation is being explored for potential use in treating nitrate salts and sludges at US Department of Energy (US DOE) underground storage tank facilities. Some of these wastes contain high concentrations of fission products and are expected to maintain equilibrium temperatures of 50--70{degrees}C for many years. The potential effects of elevated temperature and high radiation conditions on key waste form properties (e.g., mechanical integrity, leachability) are examined. After 6 months of thermal conditioning, waste form tests specimens show no degradation in mechanical integrity. Leaching at elevated temperature resulted in a small increase in leach rate (a factor of less than two), while diffusion remained the dominant mechanism of release. Full-scale polyethylene waste forms containing 50--70 wt % nitrate salt can be expected to leach a total of 5--17% of the original contaminant source term after 300 years of leaching under worst-case conditions (fully saturated at 70{degrees}C).
Date: April 1, 1993
Creator: Kalb, P. D.; Fuhrmann, M. & Colombo, P.
Partner: UNT Libraries Government Documents Department

In situ electrochemical characterization of grouted radioactive waste

Description: At the Hanford Site, twenty-eight double-shell tanks (DST) and one hundred and forty nine single-shell tanks (SST) are used for storage of radioactive liquid and sludge wastes and sat cake. A fundamental goal of the Westinghouse Hanford Company is to end the current storage practice for liquid wastes and to permanently dispose of the waste. The Hanford Defense Waste Environmental Impact Statement and subsequent record of decision has identified a cement-based waste form for disposal of DST low-level liquid waste. The low level radioactive fractions of these wastes will be immobilized in a cementitious grout at the Hanford Grout Processing Facility and disposed of in concrete vaults of the Grout Disposal Facility. Prior to closing each vault, postcuring verification will show that the final product meets the performance requirements. Any long term disposal system of radioactive waste will require monitoring to warn against structural deterioration and/or leach of the radioactive or hazardous components into the environment. We are investigating the possibility of monitoring the degree of immobilization of the waste by embedding a grid of long-lasting electrodes in grout. This work describes our ongoing attempts to understand the physics and chemistry of charge carriers in the grout under various load conditions.
Date: April 1, 1993
Creator: Gu, Jingyan; Shen, Wu-Mian; Tomkiewicz, Micha & Kruger, A. A.
Partner: UNT Libraries Government Documents Department

Leach testing of in situ stabilization grouts containing additives to sequester contaminants

Description: This document discusses laboratory testing performed by Pacific Northwest Laboratory (PNL) for Westinghouse Hanford Company (WHC) of special grout formulations that incorporate specific sequestering agents to help improve the ability of the cement to resist contaminant leaching. To enhance the sequestering of contaminants we chose five additives to introduce (singly) to the control cement. The additives were Florida pebble phosphate, clinoptilolite (a natural zeolite), ferrous sulfide (a reductant), a mixed bed organic ion exchange resin and a proprietary anion-adsorbing mixed metal oxide. These additives were added one per test to the standard formulation and used to encapsulate a diluted high-salt alkaline liquid waste that is produced after various processes to remove uranium and plutonium from spent nuclear fuel. This report documents the testing of these additives.
Date: April 1, 1993
Creator: Serne, R.J.; Ames, L.L.; Martin, P.F.C.; LeGore, V.L.; Lindenmeier, C.W. (Pacific Northwest Lab., Richland, WA (United States)) & Phillips, S.J. (Westinghouse Hanford Co., Richland, WA (United States))
Partner: UNT Libraries Government Documents Department

The Hybrid Treatment Process for treatment of mixed radioactive and hazardous wastes

Description: This paper describes a new process for treating mixed hazardous and radioactive waste, commonly called mixed waste. The process is called the Hybrid Treatment Process (HTP), so named because it is built on the 20 years of experience with vitrification of wastes in melters, and the 12 years of experience with treatment of wastes by the in situ vitrification (ISV) process.
Date: April 1, 1992
Creator: Ross, W.A. & Kindle, C.H.
Partner: UNT Libraries Government Documents Department