12 Matching Results

Search Results

Advanced search parameters have been applied.

Microbial degradation of low-level radioactive waste. Final report

Description: The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Information has been presented by a number of researchers, which indicated that those tests may be inappropriate for examining microbial degradation of cement-solidified LLW. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program was to develop modified microbial degradation test procedures that would be more appropriate than the existing procedures for evaluation of the effects of microbiologically influenced chemical attack on cement-solidified LLW. The procedures that have been developed in this work are presented and discussed. Groups of microorganisms indigenous to LLW disposal sites were employed that can metabolically convert organic and inorganic substrates into organic and mineral acids. Such acids aggressively react with cement and can ultimately lead to structural failure. Results on the application of mechanisms inherent in microbially influenced degradation of cement-based material are the focus of this final report. Data-validated evidence of the potential for microbially influenced deterioration of cement-solidified LLW and subsequent release of radionuclides developed during this study are presented.
Date: June 1, 1996
Creator: Rogers, R.D.; Hamilton, M.A.; Veeh, R.H. & McConnell, J.W. Jr
Partner: UNT Libraries Government Documents Department

Preliminary study on improvement of cementitious grout thermal conductivity for geothermal heat pump applications

Description: Preliminary studies were preformed to determine whether thermal conductivity of cementitious grouts used to backfill heat exchanger loops for geothermal heat pumps could be improved, thus improving efficiency. Grouts containing selected additives were compares with conventional bentonite and cement grouts. Significant enhancement of grout alumina grit, steel fibers, and silicon carbide increased the thermal conductivity when compared to unfilled, high solids bentonite grouts and conventional cement grouts. Furthermore, the developed grouts retained high thermal conductivity in the dry state, where as conventional bentonite and cement grouts tend to act as insulators if moisture is lost. The cementitious grouts studied can be mixed and placed using conventional grouting equipment.
Date: June 1, 1996
Creator: Allan, M.L.
Partner: UNT Libraries Government Documents Department

Success in horizontal barrier developments

Description: A successful proof of concept demonstration has been conducted of operational methods and tooling for the in situ construction of underground horizontal barriers for the control and containment of groundwater and contamination. The method involves jet grouting with specially adapted tools guided between twin, parallel wells for the placement of a grout beneath a waste site. The objective of the work is to develop reliable methods of constructing extensive, competent horizontal barriers underneath waste sites without excavating or penetrating the waste during the process.
Date: June 1, 1996
Creator: Pettit, P.J.; Ridenour, D.E. & Jalovec, J.
Partner: UNT Libraries Government Documents Department

Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste

Description: The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting.
Date: June 1, 1996
Creator: Allan, M.L.
Partner: UNT Libraries Government Documents Department

Task technical and QA plan: Thermal effects study: To evaluate saltstone properties associated with performance criteria as a function of extended exposure to temperatures typical of adiabatic curing

Description: The task to evaluate saltstone properties associated with performance criteria as a function of extended exposure to temperatures typical of adiabatic curing is described in this document and involves extension of previous qualification studies for DWPF Saltstone formulations.
Date: June 15, 1990
Creator: Orebaugh, E. G.
Partner: UNT Libraries Government Documents Department

Developing waste disposal options in the underground storage tank - integrated demonstration program

Description: The principal objective of the Underground Storage Tank - Integrated Demonstration (UST-ID Program is the demonstration and continued development of technologies suitable for the remediation of USTs. The most promising new technologies from industry, universities, national laboratories, and other government agencies are selected for demonstration, testing, and evaluation. The objective is the eventual transfer of new technologies as part of a system to full-scale remediation at US Department of Energy (DOE) sites and alternately into the private sector. Technologies under development in the UST-ID Program are targeted toward use in remediation actions at the following five DOE participant sites: Hanford, Fernald, Idaho, Oak Ridge, and Savannah River. Combined, these participant sites have more than 300 USTs containing more than 381,800 m{sup 3} (100 Mgal) of high-level and low-level radioactive liquid waste. This paper focuses on the Low-Level Waste Disposal area of the UST-ID, summarizing the two currently funded technology development projects: the Nitrate to Ammonia and Ceramic (NAC) Process and Polyethylene Encapsulation. Both technologies are considered options to the-current baseline disposal approaches being developed at the participant sites. For the Hanford Site, this baseline is a grout waste form that is nearing implementation for disposal of low-level liquid tank wastes.
Date: June 1, 1993
Creator: Cruse, J. M. & Gilchrist, R. L.
Partner: UNT Libraries Government Documents Department

Underground storage tank integrated demonstration: Evaluation of pretreatment options for Hanford tank wastes

Description: Separation science plays a central role inn the pretreatment and disposal of nuclear wastes. The potential benefits of applying chemical separations in the pretreatment of the radioactive wastes stored at the various US Department of Energy sites cover both economic and environmental incentives. This is especially true at the Hanford Site, where the huge volume (>60 Mgal) of radioactive wastes stored in underground tanks could be partitioned into a very small volume of high-level waste (HLW) and a relatively large volume of low-level waste (LLW). The cost associated with vitrifying and disposing of just the HLW fraction in a geologic repository would be much less than those associated with vitrifying and disposing of all the wastes directly. Futhermore, the quality of the LLW form (e.g., grout) would be improved due to the lower inventory of radionuclides present in the LLW stream. In this report, we present the results of an evaluation of the pretreatment options for sludge taken from two different single-shell tanks at the Hanford Site-Tanks 241-B-110 and 241-U-110 (referred to as B-110 and U-110, respectively). The pretreatment options examined for these wastes included (1) leaching of transuranic (TRU) elements from the sludge, and (2) dissolution of the sludge followed by extraction of TRUs and {sup 90}Sr. In addition, the TRU leaching approach was examined for a third tank waste type, neutralized cladding removal waste.
Date: June 1, 1993
Creator: Lumetta, G. J.; Wagner, M. J.; Colton, N. G. & Jones, E. O.
Partner: UNT Libraries Government Documents Department

Characterization results for 106-AN grout produced in a pilot-scale test

Description: The Grout Treatment Facility (GTF) at Hanford. Washington, will process the low-level fraction of selected double-shell tank (DST) wastes into a cementitious waste form. This facility, which is operated by Westinghouse Hanford Company (WHC), mixes liquid waste with cementitious materials to produce a waste form that immobilizes hazardous constituents through chemical reactions and/or microencapsulation. Over one million gallons of phosphate/sulfate waste were solidified in the first production campaign with this facility. The next tank waste scheduled for treatment is 106-AN (the waste from Tank 241-AN-106). After laboratory studies were conducted to select the grout formulation, tests using the 1/4-scale pilot facilities at the Pacific Northwest Laboratory (PNL) were conducted as part of the formulation verification process. The major objectives of these pilot-scale tests were to determine if the proposed grout formulation could be processed in the pilotscale equipment. to collect thermal information to help determine the best way to manage the grout hydration heat, and to characterize the solidified grout.
Date: June 1, 1993
Creator: Lokken, R. O.; Bagaasen, L. M.; Martin, P. F. C.; Palmer, S. E. & Anderson, C. M.
Partner: UNT Libraries Government Documents Department

Formulation verification study results for 241-AN-106 waste grout

Description: Tests were conducted to determine whether the reference formulation and variations around the formulation are adequate for solidifying 241-AN-106 (106-AN) waste into a grout waste form. The reference formulation consists of 21 wt% type I/II Portland cement, 68 wt% fly ash, and 11 wt% attapulgite clay. The mix ratio is 8.4 lb/gal. Variations in dry blend component ratios, mix ratio, and waste concentration were assessed by using a statistically designed experimental matrix consisting of 44 grout compositions. Based on the results of the statistically designed variability study, the 106-AN grout formulations tested met all the formulation criteria except for the heat of hydration.
Date: June 1, 1993
Creator: Lokken, R. O.; Martin, P. F. C.; Morrison, L. C.; Palmer, S. E. & Anderson, C. M.
Partner: UNT Libraries Government Documents Department

Task technical and QA plan: Thermal effects study: To evaluate saltstone properties associated with performance criteria as a function of extended exposure to temperatures typical of adiabatic curing

Description: The task to evaluate saltstone properties associated with performance criteria as a function of extended exposure to temperatures typical of adiabatic curing is described in this document and involves extension of previous qualification studies for DWPF Saltstone formulations.
Date: June 15, 1990
Creator: Orebaugh, E.G.
Partner: UNT Libraries Government Documents Department

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

Description: During Phase I (first 18 months) the project is segregated into four areas of reporting: (A) Grout Formulation, (B) Grout Characterization, (C) Water Quality Monitoring, (D) Subsidence Control & Contaminant Transport. The first component involves formulating a grout mixture with appropriate flowability to be used in filling complex mine voids. The Grout Characterization component involves background monitoring of water quality and precipitation at the Phase III (Longridge) mine site. This report separately progress on all components of the program in order of project subtask.
Date: June 1, 1994
Partner: UNT Libraries Government Documents Department

Properties of salt-saturated concrete and grout after six years in situ at the Waste Isolation Pilot Plant

Description: Samples of concrete and grout were recovered from short boreholes in the repository floor at the Waste Isolation Pilot Plant more than six years after the concrete and grout were placed. Plugs from the Plug Test Matrix of the Plugging and Sealing Program of Sandia National Laboratories were overcored to include a shell of host rock. The cores were analyzed at the Waterways Experiment Station to assess their condition after six years of service, having potentially been exposed to those aspects of their service environment (salt, brine, fracturing, anhydrite, etc.) that could cause deterioration. Measured values of compressive strength and pulse velocity of both the grout and the concrete equaled or exceeded values from tests performed on laboratory-tested samples of the same mixtures at ages of one month to one year after casting. The phase assemblages had changed very little. Materials performed as intended and showed virtually no chemical or physical evidence of deterioration. The lowest values for strength and pulse velocity were measured for samples taken from the Disturbed Rock Zone, indicating the influence of cracking in this zone on the properties of enclosed seal materials. There was evidence of movement of brine in the system. Crystalline phases containing magnesium, potassium, sulfate, and other ions had been deposited on free surfaces in fractures and pilot holes. There was a reaction rim in the anhydrite immediately surrounding each recovered borehole plug, suggesting interaction between grout or concrete and host rock. However, the chemical changes apparent in this reaction rim were not reflected in the chemical composition of the adjacent concrete or grout. The grout and concrete studied here showed no signs of the deterioration found to have occurred in some parts of the concrete liner of the Waste Isolation Pilot Plant waste handling shaft.
Date: June 1, 1993
Creator: Wakeley, L. D.; Harrington, P. T. & Weiss, C. A. Jr.
Partner: UNT Libraries Government Documents Department