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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

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

Mathematical modeling of permeation grouting and subsurface barrier performance

Description: The injection of solution grouts into the subsurface can be used to form underground barriers for the containment of contaminants. The technology requires identifying suitable grout materials, specifically fluids which exhibit a large increase in viscosity after injection and eventually solidify after a controllable period, thus sealing permeable zones. The authors have developed a new fluid property module for the reservoir simulator TOUGH2 to model grout injection, taking into account the increase of liquid viscosity as a function of time and gel concentration. They have also incorporated into the simulator a model which calculates soil hydraulic properties after solidification of the gel within the pore space. The new fluid property module has been used to design and analyze laboratory experiments and field pilot tests in saturated and unsaturated formations under a variety of subsurface conditions. These applications include modeling barrier emplacement in highly heterogeneous soils in the vadose zone, grout injection into the saturated zone in combination with extraction wells for flow control, the design of verification strategies, and the analysis of barrier performance. In this paper the authors discuss the modeling approach and present simulation results of multiple grout injections into a heterogeneous, unsaturated formation.
Date: September 1, 1996
Creator: Finsterle, S.; Oldenburg, C.M.; James, A.L.; Pruess, K. & Moridis, G.J.
Partner: UNT Libraries Government Documents Department

Materials testing for in situ stabilization treatability study of INEEL mixed wastes soils

Description: This report describes the contaminant-specific materials testing phase of the In Situ Stabilization Comprehensive Environment Response, Compensation, and Liability Act (CERCLA) Treatability Study (TS). The purpose of materials testing is to measure the effectiveness of grouting agents to stabilize Idaho National Engineering and Environmental Laboratory (INEEL) Acid Pit soils and select a grout material for use in the Cold Test Demonstration and Acid Pit Stabilization Treatability Study within the Subsurface Disposal Area (SDA) at the Radioactive Waste Management Complex (RWMC). Test results will assist the selecting a grout material for the follow-on demonstrations described in Test Plan for the Cold Test Demonstration and Acid Pit Stabilization Phases of the In Situ Stabilization Treatability Study at the Radioactive Waste Management Complex.
Date: September 1, 1997
Creator: Heiser, J. & Fuhrmann, M.
Partner: UNT Libraries Government Documents Department

Low-pressure, single-point grout injection for tank heel sludge mixing and in-situ immobilization

Description: This report describes tests conducted in an approximately 9-ft diameter test tank situated outside the 336 building in Hanford`s 300 area. The tests were performed to measure the ability of jets of grout slurry to mobilize and mix simulated tank sludge. The technique is intended for in situ immobilization of tank waste heels. The current approach uses a single, rotated, larger-diameter nozzle driven at lower pressure. Due to the larger diameter, the potential for plugging is reduced and the effective radius around an injection point over which the jet is effective in mobilizing sludge from the tank bottom can be made larger. A total of three grout injection tests were conducted in a 9-ft diameter tank. In each case, a 2-in. layer of kaolin clay paste was placed on a dry tank floor to simulate a sludge heel. The clay was covered with 4 inches of water. The grout slurry, consisting of Portland cement, class F fly ash, and eater, was prepared and delivered by an offsite vendor. In the third test, the sludge in half of the tank was replaced by a layer of 20x50 mesh zeolite, and bentonite clay was added to the grout formulation. After injection, the grout was allowed to set and then the entire grout monolith was manually broken up and excavated using a jack hammer. Intact pieces of clay were visually apparent due to a sharp color contrast between the grout and clay. Remaining clay deposits were collected and weighed and suspended clay pieces within the monolith were photographed. The mobilization performance of the grout jets exceeded expectations.
Date: September 1, 1998
Creator: Whyatt, G.A. & Hymas, C.R.
Partner: UNT Libraries Government Documents Department

High volume-high value usage of flue gas desulfurization (FGD) by-products in underground mines: Phase 2 -- Field investigations. Quarterly report, January 1--March 31, 1998

Description: The factors that control the strength of FBC ash grout were the focus of work during this quarter. Samples were prepared at different water contents and placed into cylindrical PVC molds. At specified curing intervals, the grout cylinders were subjected to unconfined compressive strength testing as per procedures described in previous reports. Chemical, mineralogical, and microscopical analyses were also conducted on the samples. It was found that higher curing temperatures significantly increase the strength gain rate of the FBC ash grout, in agreement with earlier results. As expected, water content also exerts a strong influence on the strength of the grout. The compressive strength data obtained for the laboratory-prepared samples are in excellent agreement with strength data obtained on grout placed in auger holes during the field demonstrations. The data also indicate that the field samples suffered negligible deterioration over the course of the curing period in the auger holes. Analysis of the laboratory prepared grout samples using XRD revealed a mineralogy similar to the field samples. A correspondence between ettringite abundance and compressive strength was observed only during grout curing. The formation of minerals such as ettringite is apparently a good indication that curing reactions are progressing and that the grout strength is increasing, but mineral distribution by itself does not explain or predict final strength. The microscopy data, in combination with geotechnical and XRD data, suggest that the strength of the grout is largely a function of the density of an amorphous (or finely crystalline) material that comprises the majority of the cured grout. Therefore, an increase in density of this material results in an increase in grout strength.
Date: September 1, 1998
Partner: UNT Libraries Government Documents Department

Idaho Nuclear Technology and Engineering Center Low-Activity Waste Process Technology Program FY-99 Status Report

Description: The Low-Activity Waste Process Technology Program at the Idaho Nuclear Technology and Engineering Center (INTEC) anticipates that large volumes of low-level/low-activity wastes will need to be grouted prior to near-surface disposal. During fiscal year 1999, grout formulations were studied for transuranic waste derived from INTEC liquid sodium-bearing waste and for projected newly generated low-level liquid waste. Additional studies were completed on radionuclide leaching, microbial degradation, waste neutralization, and a small mockup for grouting the INTEC underground storage tank residual heels.
Date: September 30, 1999
Creator: Herbst, A. K.; McCray, J. A.; Kirkham, R. J.; Pao, J. & Hinckley, S. H.
Partner: UNT Libraries Government Documents Department

Numerical Simulations of Leakage from Underground LPG Storage Caverns

Description: To secure a stable supply of petroleum gas, underground storage caverns for liquified petroleum gas (LPG) are commonly used in many countries worldwide. Storing LPG in underground caverns requires that the surrounding rock mass remain saturated with groundwater and that the water pressure be higher than the liquid pressure inside the cavern. In previous studies, gas containment criteria for underground gas storage based on hydraulic gradient and pressure have been discussed, but these studies do not consider the physicochemical characteristics and behavior of LPG such as vaporization and dissolution in groundwater. Therefore, while these studies are very useful for designing storage caverns, they do not provide better understanding of the either the environmental effects of gas contamination or the behavior of vaporized LPG. In this study, we have performed three-phase fluid flow simulations of gas leakage from underground LPG storage caverns, using the multiphase multicomponent nonisothermal simulator TMVOC (Pruess and Battistelli, 2002), which is capable of solving the three-phase nonisothermal flow of water, gas, and a multicomponent mixture of volatile organic chemicals (VOCs) in multidimensional heterogeneous porous media. A two-dimensional cross-sectional model resembling an actual underground LPG facility in Japan was developed, and gas leakage phenomena were simulated for three different permeability models: (1) a homogeneous model, (2) a single-fault model, and (3) a heterogeneous model. In addition, the behavior of stored LPG was studied for the special case of a water curtain suddenly losing its function because of operational problems, or because of long-term effects such as clogging of boreholes. The results of the study indicate the following: (1) The water curtain system is a very powerful means for preventing gas leakage from underground storage facilities. By operating with appropriate pressure and layout, gas containment can be ensured. (2) However , in highly heterogeneous media such as fractured rock ...
Date: September 1, 2004
Creator: Yamamoto, Hajime & Pruess, Karsten
Partner: UNT Libraries Government Documents Department

Supplemental Radiological Survey Plan for the Lease of the Rooms Associated with C107 of Building K-1006 at the East Tennessee Technology Park, Oak Ridge, Tennessee

Description: In 1998, a portion of Bldg. K-1006 was leased to the Community Reuse Organization of East Tennessee (CROET) as part of the reindustrialization efforts at the East Tennessee Technology Park (ETTP). The facility was subleased and is being used as an analytical laboratory. The 1998 lease did not include rooms C107, C107-A, C107-B, C107-C, and C107-D. The lease of these rooms is now desired. These rooms comprise the area to be surveyed. The building was constructed as a laboratory facility to support the gaseous diffusion uranium enrichment process. It also contains offices and administrative spaces for laboratory personnel. After the gaseous diffusion process was shut down in the mid-1980s, the building was used to provide research and development support to ETTP environmental, safety, and health programs; the Toxic Substances Control Act Incinerator; the Central Neutralization Facility; and other multi-site waste treatment activities. It also served as the chemistry laboratory for the Environmental Technology Technical Services Organization. The activities currently conducted in Bldg. K-1006 utilize a variety of analytical techniques. Some of the major techniques being employed are X-ray analysis, electron microanalysis, and spectrochemical analysis. In 1998, a portion of Bldg. K-1006 was leased to CROET as part of the reindustrialization efforts at ETTP. The facility was subleased and is being used as an analytical laboratory. The 1998 lease did not include Rooms C107, C107-A, C107-B, C107-C, and C107-D. Some demolition of furniture and decontamination activities has taken place for Rooms C 107 and C 107-B since the last radiological survey of those rooms. In March 2009, a final remedial action (RA) was performed for the Bldg. K-1006 north basement sump. The Bldg. K-1006 north basement sump is a nominal 30-in.-diameter, 36-in.-deep concrete structure in the north corner of room C107B. The building receives groundwater in-leakage that is periodically pumped to ...
Date: September 1, 2010
Creator: M.F., Blevins
Partner: UNT Libraries Government Documents Department

In-situ stabilization of radioactively contaminated low-level solid wastes buried in shallow trenches: an assessment

Description: The potential effectiveness of materials for in-situ encapsulation of low-level, radioactively contaminated solid waste buried in shallow trenches is enumerated. Cement, clay materials, and miscellaneous sorbents, aqueous and nonaqueous gelling fluids and their combinations are available to solidify contaminated free water in trenches, to fill open voids, and to minimize radionuclide mobility. The success of the grouting technique will depend on the availability of reliable geohydrologic data and laboratory development of a mix with enhanced sorption capacity for dominant radionuclides present in the trenches. A cement-bentonite-based grout mix with low consistency for pumping, several hours controlled rate of hardening, negligible bleeding, and more than 170 kPa (25 psi) compressive strength are a few of the suggested parameters in laboratory mix development. Cost estimates of a cement-bentonite-based grout mix indicate that effective and durable encapsulation can be accomplished at a reasonable cost (about $113 per cubic meter). However, extensive implementation of the method suggests the need for a field demonstration of the method. 53 references.
Date: September 1, 1980
Creator: Arora, H.S.; Tamura, T. & Boegly, W.J.
Partner: UNT Libraries Government Documents Department

Flowability of bulk solids used in shale fracturing grouts as determined by the Jenike and Johanson method

Description: Smooth operation of the shale fracturing facility at Oak Ridge National Laboratory requires that an even, uninterrupted flow of dry solids be delivered to a mixer at a rate of approximately 1200 lb/min. Some operational difficulties have been experienced with the dry solids system at the existing facility. Occasionally the solids flow from a bin was difficult to initiate or was irregular, particularly when the storage bin was nearly empty. A new shale fracturing facility is now being designed with a solids handling system that will eliminate the current problems. This report describes the tests made to obtain the necessary information about bulk-flow properties of the dry solids that are required for the facility modifications. Flow properties of fly ash, attapulgite, pottery clay, and a blended solids mix were determined in a Jenike and Johanson Flowfactor Tester. Tests with this unit involve the consolidation of a solid at a given pressure and the measurement of the force required to create a shear plane. The procedure is repeated several times at different consolidating pressures to determine a locus of points that can be displayed graphically. Results indicate that a bottom-hopper opening of about 4 ft will be required on the new, bulk storage bins if mass flow is to be achieved. It was also found that the existing bins are quite unsuitable for either their present function or their proposed function. Since these bins have served moderately well for 14 years, the effect of aeration is obviously major; these tests indicate only an upper limit to the size of the hopper opening that will be required. Pottery clay and attapulgite were found to have flow characteristics considerably inferior to blended solids. It is known, however, that attapulgite clay will flow from the existing bins, and modification of the bin bottoms to ...
Date: September 1, 1979
Creator: McDaniel, E.W. & Weeren, H.O.
Partner: UNT Libraries Government Documents Department

Hanford waste vitrification systems risk assessment

Description: A systematic Risk Assessment was performed to identify the technical, regulatory, and programmatic uncertainties and to quantify the risks to the Hanford Site double-shell tank waste vitrification program baseline (as defined in December 1990). Mitigating strategies to reduce the overall program risk were proposed. All major program elements were evaluated, including double-shell tank waste characterization, Tank Farms, retrieval, pretreatment, vitrification, and grouting. Computer-based techniques were used to quantify risks to proceeding with construction of the Hanford Waste Vitrification Plant on the present baseline schedule. Risks to the potential vitrification of single-shell tank wastes and cesium and strontium capsules were also assessed. 62 refs., 38 figs., 26 tabs.
Date: September 1, 1991
Creator: Miller, W.C.; Hamilton, D.W.; Holton, L.K. & Bailey, J.W.
Partner: UNT Libraries Government Documents Department

Complex concentrate pretreatment FY 1986 progress report

Description: After of the transuranic elements are removed from complex concentrate waste by the TRUEX process, the remaining waste will be grouted for final storage. The purpose of this project, conducted at the Pacific Northwest Laboratory (PNL), is to support a future decision to grout the complexant waste without destroying the organic contents. In work performed this year, it has been demonstrated that grouts with acceptable parameters for the Transportable Grout Facility can be made using actual waste. The acceptability of these grouts from a regulatory view seems to be less of a problem than was thought at this time last year. None of the organics found in the waste are included on the US Environmental Protection Agency's Hazardous Chemicals List. 7 refs., 12 figs., 4 tabs.
Date: September 1, 1986
Creator: lokken, R O; Scheele, R D; Strachan, D M & Toste, A P
Partner: UNT Libraries Government Documents Department

Preliminary decommissioning study reports

Description: The Old Hydrofracture Facility (OHF) is one of approximately 76 facilities currently managed by the Oak Ridge National Laboratory (ORNL) Surplus Facilities Management Program (SFMP). This program, as part of the Department of Energy (DOE) national SFMP, is responsible for the maintenance and surveillance and the final decommissioning of radioactively contaminated surplus ORNL facilities. A long-range planning effort is being conducted that will outline the scope and objectives of the ORNL program and establish decommissioning priorities based on health and safety concerns, budget constraints, and other progammatic constraints. IN support of this SFMP planning activity, preliminary engineering assessments are being conducted for each of the ORNL surplus facilities currently managed under the program. These efforts are designed to: (1) provide an initial assessment of the potential decommissioning alternatives, (2) choose a preferred alternative and provide a justification for that choice, and (3) provide a preliminary description of the decommissioning plan, including cost and schedule estimates. This report presents the results of the preliminary analysis for the OHF.
Date: September 1, 1984
Creator: Reed, W.R.
Partner: UNT Libraries Government Documents Department

Leach test of cladding removal waste grout using Hanford groundwater

Description: This report describes laboratory experiments performed during 1986-1990 designed to produce empirical leach rate data for cladding removal waste (CRW) grout. At the completion of the laboratory work, funding was not available for report completion, and only now during final grout closeout activities is the report published. The leach rates serve as inputs to computer codes used in assessing the potential risk from the migration of waste species from disposed grout. This report discusses chemical analyses conducted on samples of CRW grout, and the results of geochemical computer code calculations that help identify mechanisms involved in the leaching process. The semi-infinite solid diffusion model was selected as the most representative model for describing leaching of grouts. The use of this model with empirically derived leach constants yields conservative predictions of waste release rates, provided no significant changes occur in the grout leach processes over long time periods. The test methods included three types of leach tests--the American Nuclear Society (ANS) 16.1 intermittent solution exchange test, a static leach test, and a once-through flow column test. The synthetic CRW used in the tests was prepared in five batches using simulated liquid waste spiked with several radionuclides: iodine ({sup 125}I), carbon ({sup 14}C), technetium ({sup 99}Tc), cesium ({sup 137}Cs), strontium ({sup 85}Sr), americium ({sup 241}Am), and plutonium ({sup 238}Pu). The grout was formed by mixing the simulated liquid waste with dry blend containing Type I and Type II Portland cement, class F fly ash, Indian Red Pottery clay, and calcium hydroxide. The mixture was allowed to set and cure at room temperature in closed containers for at least 46 days before it was tested.
Date: September 1, 1995
Creator: Serne, R.J.; Martin, W.J. & Legore, V.L.
Partner: UNT Libraries Government Documents Department

A New Parameter to Assess Hydromechanical Effect in Single-hole Hydraulic Testing and Grouting

Description: Grouting or filling of the open voids in fractured rock is done by introducing a fluid, a grout, through boreholes under pressure. The grout may be either a Newtonian fluid or a Bingham fluid. The penetration of the grout and the resulting pressure profile may give rise to hydromechanical effects, which depends on factors such as the fracture aperture, pressure at the borehole and the rheological properties of the grout. In this paper, we postulate that a new parameter, {angstrom}, which is the integral of the fluid pressure change in the fracture plane, is an appropriate measure to describe the change in fracture aperture volume due to a change in effective stress. In many cases, analytic expressions are available to calculate pressure profiles for relevant input data and the {angstrom} parameter. The approach is verified against a fully coupled hydromechanical simulator for the case of a Newtonian fluid. Results of the verification exercise show that the new approach is reasonable and that the {angstrom}-parameter is a good measure for the fracture volume change: i.e., the larger the {angstrom}-parameter, the larger the fracture volume change, in an almost linear fashion. To demonstrate the application of the approach, short duration hydraulic tests and constant pressure grouting are studied. Concluded is that using analytic expressions for penetration lengths and pressure profiles to calculate the {angstrom} parameter provides a possibility to describe a complex situation and compare, discuss and weigh the impact of hydromechanical couplings for different alternatives. Further, the analyses identify an effect of high-pressure grouting, where uncontrolled grouting of larger fractures and insufficient (or less-than-expected) sealing of finer fractures is a potential result.
Date: September 1, 2007
Creator: Rutqvist, Jonny; Fransson, A.; Tsang, C.-F.; Rutqvist, J. & Gustafson, G.
Partner: UNT Libraries Government Documents Department


Description: The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar into Tank 50. Saltstone samples were prepared with an 'MCU' type salt solution spiked with ammonia. The ammonia released from the saltstone was captured and analyzed. The ammonia concentration found in the headspace of samples maintained at 95 C and 1 atm was, to 95% confidence, less than or equal to 3.9 mg/L. Tank 50 is fed by several influent streams. The salt solution from Tank 50 is pumped to the salt feed tank (SFT) in the Saltstone Production Facility (SPF). The premix materials cement, slag and fly ash are blended together prior to transfer to the grout mixer. The premix is fed to the grout mixer in the SPF and the salt solution is incorporated into the premix in the grout mixer, yielding saltstone slurry. The saltstone slurry drops into a hopper and then is pumped to the vault. The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar{reg_sign} L into Tank 50. Waste Solidification-Engineering requested that the Savannah River National Laboratory (SRNL) perform testing to characterize the release of ammonia in curing saltstone at 95 C. The test temperature represents the maximum allowable temperature in the Saltstone Disposal Facility (SDF). Ammonia may be present in the salt solution and premix materials, or may be produced by chemical reactions when the premix and salt solution are combined. A final report (SRNS-STI-2008-00120, Rev. 0) will be issued that will cover in more depth the information presented in this report.
Date: September 26, 2008
Creator: Zamecnik, J & Alex Cozzi, A
Partner: UNT Libraries Government Documents Department

Hanford Tank 241-C-106: Impact of Cement Reactions on Release of Contaminants from Residual Waste

Description: The CH2M HILL Hanford Group, Inc. (CH2M HILL) is producing risk/performance assessments to support the closure of single-shell tanks at the U.S. Department of Energy's Hanford Site. As part of this effort, staff at Pacific Northwest National Laboratory were asked to develop release models for contaminants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. Initial work to produce release models was conducted on residual tank sludge using pure water as the leaching agent. The results were reported in an earlier report. The decision has now been made to close the tanks after waste retrieval with a cementitious grout to minimize infiltration and maintain the physical integrity of the tanks. This report describes testing of the residual waste with a leaching solution that simulates the composition of water passing through the grout and contacting the residual waste at the bottom of the tank.
Date: September 1, 2006
Creator: Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F. & Schaef, Herbert T.
Partner: UNT Libraries Government Documents Department

Radionuclide Retention in Concrete Waste Forms

Description: Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.
Date: September 30, 2010
Creator: Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M. & Wood, Marcus I.
Partner: UNT Libraries Government Documents Department