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Characterization of a low-level radioactive waste grout: Sampling and test results

Description: WHC manages and operates the grout treatment facility at Hanford as part of a DOE program to clean up wastes stored at federal nuclear production sites. PNL provides support to the grout disposal program through pilot-scale tests, performance assessments, and formulation verification activities. in 1988 and 1989, over one million gallons of a low-level radioactive liquid waste was processed through the facility to produce a grout waste that was then deposited in an underground vault. The liquid waste was phosphate/sulfate waste (PSW) generated in decontamination of the N Reactor. PNL sampled and tested the grout produced during the second half of the PSW campaign to support quality verification activities prior to grout vault closure. Samples of grout were obtained by inserting nested-tube samplers into the grout slurry in the vault. After the grout had cured, the inner tube of the sampler was removed and the grout samples extracted. Tests for compressive strength, sonic velocity, and leach testing were used to assess grout quality; results were compared to those from pilot-scale test grouts made with a simulated PSW. The grout produced during the second half of the PSW campaign exceeded compressive strength and leachability formulation criteria. The nested tube samplers were effective in collecting samples of grout although their use introduced greater variability into the compressive strength data.
Date: December 1, 1992
Creator: Martin, P.F.C. & Lokken, R.O.
Partner: UNT Libraries Government Documents Department

A case study: using a multi-grout barrier to control {sup 90}Sr release at ORNL

Description: During summer 1996, low-pressure permeation grouting was performed inside portions of four unlined, shallow waste disposal trenches at a radioactive waste burial ground that was opened in 1951 at the Oak Ridge National Laboratory (ORNL). The objective was to selectively control sources that release about 25 percent of all strontium 90 (90Sr) discharged from the ORNL complex. A unique grouting methodology was adapted to control interaction of wastes with natural runoff at this humid site. Driven sleeve pipes were injected 4 to 5 times with multiple formulae of type III portland cement- based grouts, ultra fine cement-based grouts, and acrylamide grouts. Multiple-hole grout injection was monitored continuously using real time monitoring equipment. Apparent Lugeon values were calculated during grouting operations and grout formulae were continually adjusted during injection to maximize permeation, durability, and economy. Over 500 cubic meters of combined grout types were emplaced. At the completion of production grouting, the effectiveness of grout spread and in situ hydraulic conductivity of the grouted mass were assessed. The average residual hydraulic conductivity measured in more than 20 check pipes was less than I x 10` cm/sec. Hydrologic monitoring has been established to determine the overall effectiveness of the project for 9OSr control.
Date: February 1, 1997
Creator: Long, J.D.; Huff, D.D. & Naudts, A.A.
Partner: UNT Libraries Government Documents Department

Lance water injection tests adjacent to the 281-3H retention basin at the Savannah River Site, Aiken, South Carolina

Description: A pilot-scale field demonstration of waste isolation using viscous- liquid containment barriers has been planned for the 281-3H retention basin at the Savannah River Site, Aiken, SC. The 281-3H basin is a shallow retention/seepage basin contaminated mainly by radionuclides. The viscous-liquid containment barrier utilizes the permeation of liquid grout to either entomb the contaminants within a monolithic grout structure or to isolate the waste by drastically reducing the permeability, of the soils around the plume. A clear understanding of the hydrogeologic setting of the retention basin is necessary for proper design of the viscous liquid barrier. To aid in the understanding of the hydrogeology of the 281-3H retention basin, and to obtain critical parameters necessary for grout injection design, a series of tests were undertaken in a region immediately adjacent to the basin. The objectives of the LWIT were: 1. To evaluate the general performance of the Lance Injection Technique for grout emplacement at the site, including the range and upper limits of injection pressures, the flow rates applicable for site conditions, as well as the mechanical forces needed for lance penetration. 2. To obtain detailed information on the injectability of the soils immediately adjacent to the H-area retention basin. 3. To identify any high permeability zones suitable for injection and evaluate their spatial distribution. 4. To perform ground penetrating radar (GPR) to gain information on the structure of the soil column and to compare the results with LWIT data. This report will focus on results pertinent to these objectives.
Date: September 1, 1996
Creator: Freifeld, B.; Myer, L.; Moridis, G.; Cook, P.; James, A.; Pellerin, L. et al.
Partner: UNT Libraries Government Documents Department

Performance assessment of grouted double-shell tank waste disposal at Hanford. Revision 1

Description: This document assesses the performance of the Grout Disposal Facility after closure. The facility and disposal environment are modeled to predict the long-term impacts of the disposal action. The document concludes that the disposal system provides reasonable assurance that doses to the public will remain within the performance objectives. This document is required for DOC Order 5820.2A.
Date: September 1, 1994
Creator: Shade, J.W., Kincaid, C.T.; Whyatt, G.A.; Rhoads, K.; Westsik, J.H. Jr.; Freshley, M.D.; Blanchard, K.A. et al.
Partner: UNT Libraries Government Documents Department

Thermally conductive cementitious grouts for geothermal heat pumps. Progress report FY 1998

Description: Research commenced in FY 97 to determine the suitability of superplasticized cement-sand grouts for backfilling vertical boreholes used with geothermal heat pump (GHP) systems. The overall objectives were to develop, evaluate and demonstrate cementitious grouts that could reduce the required bore length and improve the performance of GHPs. This report summarizes the accomplishments in FY 98. The developed thermally conductive grout consists of cement, water, a particular grade of silica sand, superplasticizer and a small amount of bentonite. While the primary function of the grout is to facilitate heat transfer between the U-loop and surrounding formation, it is also essential that the grout act as an effective borehole sealant. Two types of permeability (hydraulic conductivity) tests was conducted to evaluate the sealing performance of the cement-sand grout. Additional properties of the proposed grout that were investigated include bleeding, shrinkage, bond strength, freeze-thaw durability, compressive, flexural and tensile strengths, elastic modulus, Poisson`s ratio and ultrasonic pulse velocity.
Date: November 1, 1998
Creator: Allan, M.L. & Philippacopoulos, A.J.
Partner: UNT Libraries Government Documents Department

Demonstration of In-Situ Stabilization of Buried Waste at Pit G-11 at the Brookhaven National laboratory Glass Pits Disposal Site

Description: In 1989 BNL was added to the EPAs National Priorities List. The site is divided into seven operable units (OU). OU-I includes the former landfill area. The field task site is noted as the AOC 2C Glass Holes location. Beginning in the 1960s and continuing into the 1980s, BNL disposed of laboratory waste (glassware, chemicals and animal carcasses) in numerous shallow pits. The drivers for remediating the pits are; historical records that indicate hazardous materials may have been disposed of in the pits; ground water contamination down gradient of the pits; a test excavation of one of the glass holes that unearthed laboratory glass bottles with unidentified liquids still contained; and the fact that BNL rests atop an EPA designated sole-source aquifer. The specific site chosen for this demonstration was pit G-11. The requirements that lead to choosing this pit were; a well characterized pit and a relatively isolated pit where our construction operations would not impact on adjacent pits. The glass holes area, including pit G-11, was comprehensively surveyed using a suite of geophysical techniques (e.g., EM-31, EM-61, GPR). Prior to stabilizing the waste form a subsurface barrier was constructed to contain the entire waste pit. The pit contents were then stabilized using a cement grout applied via jet grouting. The stabilization was performed to make removal of the waste from the pit easier and safer in terms of worker exposure. The grouting process would mix and masticate the waste and grout and form a single monolithic waste form. This large monolith would then be subdivided into smaller 4 foot by 4 foot by 10-12 foot block using a demolition grout. The smaller blocks would then be easily removed from the site and disposed of in a CERCLA waste site.
Date: January 1, 1999
Creator: Dwyer, B.P.; Gilbert, J. & Heiser, J.
Partner: UNT Libraries Government Documents Department

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

Characterization Plan for the Old Hydrofracture Facility

Description: US Department of Energy (DOE) facilities are required to comply fully with all federal and state regulations. In response to this requirement, the Oak Ridge National Laboratory (ORNL) has established the remedial action program, to provide comprehensive management of areas where past research, development, and waste management activities have been conducted and have resulted in residual contamination of facilities or the environment. One of the objectives of this program is to define the extent of contamination at these sites. The intent is to document the known environmental characteristics of the sites and identify the additional actions, such as sampling, analytical measurements, and modeling, necessary to confirm contamination and the possible migration of contaminants from the sites. One of these sites is the Old Hydrofracture Facility (OHF). The OHF was used for the permanent disposal of liquid radioactive waste in impermeable shale formations at depths ranging from about 230 to 300 m (750 to 1000 ft), from 1964 to 1979. The liquid waste was blended into a pumpable grout by mixing it with cement and special clays used to immobilize radionuclides against groundwater transport. This report summarizes the results of several studies at ORNL that have measured the concentration of radionuclides and, to some extent, concentrations of hazardous chemicals in the sediment of the impoundment, as well as the concentrations in soils and groundwater near the facility. The report addresses only the contamination of and the potential releases to the environment that might result from the facility per se and makes not attempt to address potential releases that might result from permanent disposal of wastes (i.e., the grout sheets) during its operation. Outlined in the report are the additional actions needed to obtain the information required to confirm the extent of contamination within the facility. The major efforts include the measurement ...
Date: January 1, 1999
Creator: Francis, C.W.
Partner: UNT Libraries Government Documents Department

Alternative disposal options for alpha-mixed low-level waste

Description: This paper presents several disposal options for the Department of Energy alpha-mixed low-level waste. The mixed nature of the waste favors thermally treating the waste to either an iron-enriched basalt or glass waste form, at which point a multitude of reasonable disposal options, including in-state disposal, are a possibility. Most notably, these waste forms will meet the land-ban restrictions. However, the thermal treatment of this waste involves considerable waste handling and complicated/expensive offgas systems with secondary waste management problems. In the United States, public perception of offgas systems in the radioactive incinerator area is unfavorable. The alternatives presented here are nonthermal in nature and involve homogenizing the waste with cryogenic techniques followed by complete encapsulation with a variety of chemical/grouting agents into retrievable waste forms. Once encapsulated, the waste forms are suitable for transport out of the state or for actual in-state disposal. This paper investigates variances that would have to be obtained and contrasts the alternative encapsulation idea with the thermal treatment option.
Date: December 1, 1995
Creator: Loomis, G.G. & Sherick, M.J.
Partner: UNT Libraries Government Documents Department

HWMA closure plan for the Waste Calcining Facility at the Idaho National Engineering Laboratory

Description: The Waste Calcining Facility (WCF) calcined and evaporated aqueous wastes generated from the reprocessing of spent nuclear fuel. The calciner operated from 1963 to 1981, primarily processing high level waste from the first cycle of spent fuel extraction. Following the calciner shutdown the evaporator system concentrated high activity aqueous waste from 1983 until 1987. In 1988, US Department of Energy Idaho Operations Office (DOE-ID) requested interim status for the evaporator system, in anticipation of future use of the evaporator system. The evaporator system has not been operated since it received interim status. At the present time, DOE-ID is completing construction on a new evaporator at the New Waste Calcining Facility (NWCF) and the evaporator at the WCF is not needed. The decision to not use the WCF evaporator requires Lockheed Idaho Technologies Company (LITCO) and DOE-ID to close these units. After a detailed evaluation of closure options, LITCO and DOE-ID have determined the safest option is to fill the voids (grout the vessels, cells and waste pile) and close the WCF to meet the requirements applicable to landfills. The WCF will be covered with a concrete cap that will meet the closure standards. In addition, it was decided to apply these closure standards to the calcining system since it is contained within the WCF building. The paper describes the site, waste inventory, closure activities, and post-closure care plans.
Date: May 1, 1996
Partner: UNT Libraries Government Documents Department

Ultrafine cement grout for sealing underground nuclear waste repositories

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 their host. This paper presents the results of collaborative work between Whitesell Laboratories, operated by Atomic Energy of Canada, Ltd., and Sandia National Laboratories; the work was undertaken in support of the Waste Isolation Pilot Plant (WIPP). 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 plugging and sealing program, specifically the development and optimization of Ultrafine cementitious grout that can be injected to adequately lower excessive, strain-induced permeability in the Distributed Rock Zone (DRZ) surrounding underground excavations. Innovative equipment and procedures employed in the laboratory produced a usable cement-based grout whose particles are 90% smaller than 8 microns and average 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 8 microns and lowered the gas permeability of the DRZ by three orders of magnitude. Following the WIPP test, additional work produced an improved version of the grout containing particles 90% smaller than 6 microns and averaging 2 microns. This grout can be produced in the dry form at a competitive cost ready to mix.
Date: February 1, 1996
Creator: Ahrens, E.H. & Onofrei, M.
Partner: UNT Libraries Government Documents Department

A field test of a waste containment technology using a new generation of injectable barrier liquids

Description: A first stage field injection of a new generation of barrier liquids was successfully completed. Two types of barrier liquids, colloidal silica (CS) and polysiloxane (PSX), were injected into heterogeneous unsaturated deposits of sand, silt, and gravel typical of many of the arid DOE cleanup sites and particularly analogous to the conditions of the Hanford Site. Successful injection by commercially available chemical grouting equipment and the tube-a-manchette technique was demonstrated. Excavation of the grout bulbs permitted visual evaluation of the soil permeation by the grout, as well as sample collection. Both grouts effectively permeated all of the formation. The PSX visually appeared to perform better, producing a more uniform and symmetric permeation regardless of heterogeneity, filling large as well as small pores and providing more structural strength than the CS. Numerical simulation of the injection tests incorporated a stochastic field to represent site heterogeneity and was able to replicate the general test behavior. Tiltmeters were used successfully to monitor surface displacements during grout injection.
Date: August 1, 1996
Creator: Moridis, G.; Apps, J.; Persoff, P.; Myer, L.; Muller, S.; Pruess, K. et al.
Partner: UNT Libraries Government Documents Department

Physical barriers formed from gelling liquids: 1. numerical design of laboratory and field experiments

Description: The emplacement of liquids under controlled viscosity conditions is investigated by means of numerical simulations. Design calculations are performed for a laboratory experiment on a decimeter scale, and a field experiment on a meter scale. The purpose of the laboratory experiment is to study the behavior of multiple gout plumes when injected in a porous medium. The calculations for the field trial aim at designing a grout injection test from a vertical well in order to create a grout plume of a significant extent in the subsurface.
Date: January 1, 1994
Creator: Finsterle, S.; Moridis, G.J.; Pruess, K. & Persoff, P.
Partner: UNT Libraries Government Documents Department

Durability of double-shell tank waste grouts

Description: This report summarizes results of studies conducted in FY89 to assess the durability of grouted DST waste. This is in support of WHC`s grout disposal program to determine the physical/chemical properties of simulated DST grouts cured for extended time periods at elevated temperatures. This report presents results of tests on simulated DST grout samples cured up to 6 months at 75 to 95 C. All the testing and characterization were done on a single formulation of DS slurry feed grout. The simulated waste was the same as in the Nov. 1988 pilot- scale test of grout processing. The dry blend (47 wt% slag, 47 wt% class F fly ash, 6 wt% type I/II portland cement) was mixed with the simulated waste at a mix ratio of 9 lb/gal. Resultant grout slurry was cast into molds and cured at 100% RH at 75, 85, and 95 C. Leach resistance and compressive strength decreased with curing times and temperatures. The samples absorbed water during curing (up to 9 wt%) as a result of osmotic pressures caused by the high salt content within the grout, and this may have caused microcracking and reduced strength. Cracking due to increased internal pressures from salt crystallization also may have occurred as the samples cooled from curing.
Date: December 1, 1992
Creator: Lokken, R.O.; Martin, P.F.C. & Shade, J.W.
Partner: UNT Libraries Government Documents Department

Removal action report on Waste Area Grouping 4 seeps 4 and 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: This report documents removal action activities for a Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) non-time-critical removal action as described in the Action Memorandum prepared in 1996. The technical objective of this removal action was to reduce the release of strontium 90 ({sup 90}Sr) into an ephemeral tributary to White Oak Creek from Waste Area Grouping 4 (WAG 4) seeps, as measured at Monitoring Station (MS) 1 at ORNL, Oak Ridge, TN. Design was initiated in early January 1996 and grouting activities were completed in late October 9996. Portions of four waste disposal trenches were injected using low-temperature permeation grouting technology with multiple formulations of grouts to reduce the in situ hydraulic conductivity of the waste materials and ultimately reduce the off-site transport of {sup 90}Sr.
Date: December 1, 1996
Partner: UNT Libraries Government Documents Department

Solidifications/stabilization treatability study of a mixed waste sludge

Description: The Department of Energy Oak Ridge Operations Office signed a Federal Facility Compliance Agreement with the US Environmental Protection Agency Region IV regarding mixed wastes from the Oak Ridge Reservation (ORR) subject to the land disposal restriction provisions of the Resource Conservation and Recovery Act (RCRA). This agreement required treatability studies of solidification/stabilization (S/S) on mixed wastes from the ORR. This paper reports the results of the cementitious S/S studies conducted on a waste water treatment sludge generated from biodenitrification and heavy metals precipitation. For the cementitious waste forms, the additives tested were Portland cement, ground granulated blast furnace slag, Class F fly ash, and perlite. The properties measured on the treated waste were density, free-standing liquid, unconfined compressive strength, and TCLP performance. Spiking up to 10,000, 10,000, and 4,400 mg/kg of nickel, lead, and cadmium, respectively, was conducted to test waste composition variability and the stabilization limitations of the binding agents. The results indicated that nickel, lead and cadmium were stabilized fairly well in the high pH hydroxide-carbonate- ``bug bones`` sludge, but also clearly confirmed the established stabilization potential of cementitious S/S for these RCRA metals.
Date: March 1, 1996
Creator: Spence, R.D. & Stine, E.F.
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 design study for a medium-scale field demonstration of the viscous barrier technology

Description: This report is the design study for a medium-scale field demonstration of Lawrence Berkeley National Laboratory`s new subsurface containment technology for waste isolation using a new generation of barrier liquids. The test site is located in central California in a quarry owned by the Los Banos Gravel Company in Los Banos, California, in heterogeneous unsaturated deposits of sand, silt, and -ravel typical of many of the and DOE cleanup sites and particularly analogous to the Hanford site. The coals of the field demonstration are (a) to demonstrate the ability to create a continuous subsurface barrier isolating a medium-scale volume (30 ft long by 30 ft wide by 20 ft deep, i.e. 1/10th to 1/8th the size of a buried tank at the Hanford Reservation) in the subsurface, and (b) to demonstrate the continuity, performance, and integrity of the barrier.
Date: September 1, 1996
Creator: Moridis, G.; Yen, P.; Persoff, P.; Finsterle, S.; Williams, P.; Myer, L. et al.
Partner: UNT Libraries Government Documents Department

Grout and glass performance in support of stabilization/solidification of ORNL tank sludges

Description: Wastewater at Oak Ridge National Laboratory (ORNL) is collected, evaporated, and stored in the Melton Valley Storage Tanks (MVST) and Bethel Valley Evaporator Storage Tanks (BVEST) pending treatment for disposal. In addition, some sludges and supernatants also requiring treatment remain in two inactive tank systems: the gunite and associated tanks (GAAT) and the old hydrofracture (OHF) tank. The waste consists of two phases: sludge and supernatant. The sludges contain a high amount of radioactivity, and some are classified as TRU sludges. Some Resource Conservation and Recovery Act (RCRA) metal concentrations are high enough to be defined as RCRA hazardous; therefore, these sludges are presumed to be mixed TRU waste. Grouting and vitrification are currently two likely stabilization/solidification alternatives for mixed wastes. Grouting has been used to stabilize/solidify hazardous and low-level radioactive waste for decades. Vitrification has been developed as a high-level radioactive alternative for decades and has been under development recently as an alternative disposal technology for mixed waste. The objective of this project is to define an envelope, or operating window, for grout and glass formulations for ORNL tank sludges. Formulations will be defined for the average composition of each of the major tank farms (BVEST/MVST, GAAT, and OHF) and for an overall average composition of all tank farms. This objective is to be accomplished using surrogates of the tank sludges with hot testing of actual tank sludges to check the efficacy of the surrogates.
Date: September 1, 1998
Creator: Spence, R.D.; Mattus, C.H. & Mattus, A.J.
Partner: UNT Libraries Government Documents Department

Disposal of fluidized-bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly technical progress report, December 1994--February 1995

Description: Research continued on the disposal of fluidized-bed combustion products in underground mines in order to control acid mine drainage and ground subsidence. This quarter, the installation of a coal ash grout into an underground mine void was accomplished. A mixture of 10% portland cement was added to the ash. Problems arose with the clumping of the grout.
Date: March 1, 1995
Partner: UNT Libraries Government Documents Department

Formulation verification study results for Tank 106-AN waste

Description: Because of the excessive heat generated during hydration of double- shell tank waste grouts using 47 wt% blast furnace slag/47 wt% class F fly ash/6 wt% type I/II Portland cement, a modified formulation was recommended for testing of Tank 106-AN grout. The recommended dry blend is: 40 wt% agricultural grade CaCO{sub 3} (ground limestone), 28 wt% blast furnace slag, 28 wt% class F fly ash, and 4 wt% type I/II cement. Verification studies with this dry blend showed that the only criterion not met in all cases was for drainable liquid.
Date: December 1, 1992
Creator: Lokken, R.O.
Partner: UNT Libraries Government Documents Department

Durability of double-shell slurry feed grouts: FY-90 results

Description: Plans for disposal of the low-level fraction of selected double-shell tank wastes at Hanford include grouting. Grout disposal is the process of mixing low-level liquid waste with cementitious powders and pumping the slurry to near-surface, underground concrete vaults; hydration results in the formation of a solid product that binds/encapsulates the radioactive/hazardous constituents. In this durability program, previous studies have indicated a strong impact from curing temperature/time on strength and leach resistance of DSSF grouts. The current studies were expanded to determine whether these impacts could be attributed to other factors, such as dry blend composition and waste concentration. Major conclusions: grouts from dry blends with 40 wt% limestone had lower strengths; compressive strengths and leach resistance decreased with increased curing temperature/time; leach resistance increased for grouts prepared with dilute DSSF; nitrate leach resistance increased with high slag/cement ratios, dilute DSSF, and low curing temperatures; amount of drainable liquids for grouts using diluted DSSF was lowest when slag content was high; the 2 most significant factors affecting grout properties were the slag/cement ratio and waste dilution (slag-waste reactions appear to dominate the properties of DSSF grouts).
Date: December 1, 1992
Creator: Lokken, R.O. & Martin, P.F.C.
Partner: UNT Libraries Government Documents Department

Heat of hydration of double-shell slurry feed grouts

Description: Samples of double-shell slurry feed (DSSF) grout (used in solidifying the waste stored in DS tanks at Hanford) were prepared and tested in adiabatic calorimeters to determine the effect of waste concentration and dry blend variations on the heat of hydration. Changes in DSSF waste concentration had the greatest impact on the overall heat of hydration of the grouts. Grouts prepared with dilute (100 times) DSSF had temperature rises up to 37 C less than with grouts prepared that for undiluted DSSF (15 C vs 52 C). All the grouts prepared with undiluted DSSF had temperature rises that exceeded 45 C. Partial neutralization of the DSSF with acids resulted in delayed reactions and lower temperature rises than that occurring in the reference grout. The temperature rise of a DSSF grout prepared with waste partially neutralized with HCl was 28 C after 300 hr hydration. Temperature rise for a grout made with DSSF partially neutralized with H3PO4 was 43 C. These values compare with a temperature rise of >52 C for a grout made with untreated DSSF. Decreasing the mix ratio from 9 lb/gal to 7.5 lb/gal did not significantly reduce the adiabatic temperature rise of grouts prepared with partially neutralized DSSF waste.
Date: December 1, 1992
Creator: Lokken, R.O.
Partner: UNT Libraries Government Documents Department

Completion report for the isolation and remediation of inactive liquid low-level radioactive waste tanks 7562, H-209, and T-30 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: A human health risk analysis was conducted on inactive tanks 7562, H-209 and T-30 to determine the method for remediating the tanks. Risk analysis results indicated that the health risk associated with these tanks were within or below the EPA range of concern of 1 {times} 10{sup {minus}4} to 1 {times} 10{sup {minus}6}. On the basis of these results, and with regulator approval, it was determined that either no action or in-place stabilization of the tanks would satisfy risk-based remediation goals. Therefore, a decision was made and approved by DOE to remediate these tanks in-place as a maintenance action. Tanks H-209 and T-30 were isolated from associated piping, electrical systems, and instrumentation and grouted in-place. Due to regulatory concerns over the location of tank 7562 relative to an area of subsurface soil contamination, tank 7562 was isolated from associated piping and instrumentation and left in-place empty. Completion of these maintenance actions has met the intent of the Federal Facility Agreement (FFA) for remediation of inactive tanks H-209 and T-30. EPA and Tennessee Department of Environment and Conservation (TDEC) will be requested to approve a change to the FFA removing tanks H-209 and T-30 from the Appendix F list of inactive tanks. The request for removal of tank 7562 from Appendix F will be submitted pending final disposition of the tank. Since the associated tank piping systems remain in-place, it will further be requested that these systems be included as individual sites in Appendix C of the FFA for future remedial consideration.
Date: December 1, 1996
Partner: UNT Libraries Government Documents Department