A remote characterization system for subsurface mapping of buried waste sites

Mapping of buried objects and regions of chemical and radiological contamination is required at US Department of Energy (DOE) buried waste sites. The DOE Office of Technology Development Robotics Integrated Program has initiated a project to develop and demonstrate a remotely controlled subsurface sensing system, called the Remote Characterization System (RCS). This project, a collaborative effort by five of the National Laboratories, involves the development of a unique low-signature survey vehicle, a base station, radio telemetry data links, satellite-based vehicle tracking, stereo vision, and sensors for non-invasive inspection of the surface and subsurface. To minimize interference with on-board sensors, the survey vehicle has been constructed predominatantly of non-metallic materials. The vehicle is self-propelled and will be guided by an operator located at a remote base station. The RCS sensors will be environmentally sealed and internally cooled to preclude contamination during use. Ground-penetrating radar, magnetometers, and conductivity devices are planned for geophysical surveys. Chemical and radiological sensors will be provided to locate hot spots and to provide isotopic concentration data

Report on geological surveys in the 300-FF-1 operable unit

This report describes a set of geophysical surveys performed by the Pacific Northwest Laboratory at selected locations within the 300-FF-1 Operable Unit at Hanford. Field work and preliminary data processing activities were initiated in September 1989. These actions were terminated by the Westinghouse Hanford Company before completion in December 1989. Work was reinitiated in October 1990, to complete the processing of the data that had already been collected and to report the results. Because the field work was only partially completed, the task objectives, as presented in the Statement of Work, could not be fully met. This report is, therefore, a progress report covering the work performed through December 11, 1989. This task involved (1) ground-penetrating radar surveys of the 618-4 and 618-5 Burial Grounds, and (2) ground-penetrating radar and electromagnetic induction surveys along the assumed routes of the abandoned process sewers and radioactive liquid waste sewers in the 300-FF-1 Operable Unit. The surveys in the burial grounds were intended to identify burial trenches and pits, to determine the depth of fill, and to locate waste materials, including any that might be outside the perimeter fences. The surveys along the sewer routes were intended, first, to confirm the locations of the sewers as shown on existing maps or to otherwise accurately determine their locations, and second, to attempt to identify locations of possible leaks. 3 refs., 3 figs., 2 tabs

Radar Location Equipment Development Program: Phase I

The work described in this report represents the first phase of a planned three-phase project designed to develop a radar system for monitoring waste canisters stored in a thick layer of bedded salt at the Waste Isolation Pilot Plant near Carlsbad, New Mexico. The canisters will be contained in holes drilled into the floor of the underground waste storage facility. It is hoped that these measurements can be made to accuracies of +-5 cm and +-2/sup 0/, respectively. The initial phase of this project was primarily a feasibility study. Its principal objective was to evaluate the potential effectiveness of the radar method in the planned canister monitoring application. Its scope included an investigation of the characteristics of radar signals backscattered from waste canisters, a test of preliminary data analysis methods, an assessment of the effects of salt and bentonite (a proposed backfill material) on the propagation of the radar signals, and a review of current ground-penetrating radar technology. A laboratory experiment was performed in which radar signals were backscattered from simulated waste canisters. The radar data were recorded by a digital data acquisition system and were subsequently analyzed by three different computer-based methods to extract estimates of canister location and tilt. Each of these methods yielded results that were accurate within a few centimeters in canister location and within 1/sup 0/ in canister tilt. Measurements were also made to determine the signal propagation velocities in salt and bentonite (actually a bentonite/sand mixture) and to estimate the signal attenuation rate in the bentonite. Finally, a product survey and a literature search were made to identify available ground-penetrating radar systems and alternative antenna designs that may be particularly suitable for this unique application. 10 refs., 21 figs., 4 tabs

Research, development, demonstration, testing, and evaluation characterization technology project: FY90 year-end report on subsurface detection methods

Most of the site cleanup projects to be conducted at US Department of Energy (DOE) facilities will include subsurface investigations using geophysical sensors. When performed at an early state of a site characterization effort, they will help define site boundaries and waste distributions, provide guidance for the optimization of subsurface sampling plans, reduce the cost of site exploration tasks, and enhance the safety of personnel involved in sampling and excavation activities. In FY 89, researchers of Pacific Northwest Laboratory constructed a digital data acquisition system (DAS) to be used in geophysical surveys of hazardous waste burial sites. The DAS is essentially a specialized microcomputer that has been ruggedized to permit operation on a moving off-road vehicle. It was designed primarily to record and display ground-penetrating radar (GPR) data, but it is capable of simultaneously or separately recording data produced by other types of geophysical sensors. Our work in FY 90 focused primarily on improving certain hardware components of the DAS and on writing the software needed to process and display the recorded data on a personal computer (PC)-based data processing system. A secondary aspect of our work during the past year was constructed and testing a breadboard version of a time-domain metal detector. Metal detectors are commonly used in site characterization surveys to detect and map metallic wastes such as 55-gal drums, storage tanks, pipes, and cables. However, currently available instruments tend to be unstable, difficult to use, and generally unsuitable for quantitative site characterization measurements

Geophysical surveys for buried waste detection at the Idaho National Engineering Laboratory

This report describes a series of geophysical surveys performed at the Idaho National Engineering Laboratory (INEL). The main purpose of the surveys was to evaluate techniques, principally ground-penetrating radar, for detecting and mapping radioactive wastes buried in shallow trenches and pits. A second purpose was to determine the feasibility of using ground-penetrating radar to measure the depth of basalt bedrock. A prototype geophyscal survey system developed by the US Department of Energy's Pacific Northwest Laboratory was used for this study. Radar, magnetometer, and metal detector measurements were made at three sites in the Radioactive Waste Management Complex (RWMC) at INEL. Radar measurements were made at fourth site adjacent to the RWMC. The combination of three geophysical methods was shown to provide considerable information about the distribution of buried waste materials. The tests confirmed the potential effectiveness of the radar method, but they also pointed out the need for continued research and development in ground-penetrating radar technology. The radar system tested in this study appears to be capable of measuring the depth to basalt in the vicinity of the RWMC

Characterization of the Hanford 300 area burial grounds. Final report: decontamination and decommissioning

Pacific Northwest Laboratory conducted a series of investigations at the Hanford Site to develop technologies for characterizing and monitoring radioactive waste burial facilities that could be used in determining appropriate decommissioning alternatives. Specific objectives were to develop unique functional geophysics, geochemical, soil physics, numerical modeling, and biological methodologies needed to better characterize and monitor buried radioactive waste disposal sites. To meet these objectives the project was divided into four tasks: Task I, Geophysical Evaluation - Geophysical surveys were taken to locate and define the gross composition of waste materials. Task II, Geochemical Analysis - The interaction of disposed radionuclides with geologic media was analyzed through an integrated radiochemical procedure. Task III, Fluid Transport and Modeling - Computer modeling of water migration in partially saturated groundwater systems was verified with actual data collected at a field test facility used to monitor micrometeorological and geohydrological energy and mass transfer factors. Task IV, Biological Transport - Several biological organisms were evaluated for potential radionuclide uptake and transport. Along with the four tasks, the project included a review of pertinent literature and regulatory issues that might affect the alternatives selected. Surveys were taken of the surrounding area and specific sites and operations. The overall results indicated that the 300 Area Burial Grounds have been adequate in containing radioactive waste. Based on the results of the project, the alternatives identified for decommissioning these sites are exhumation and translocation, entombment, perpetual care, and abandonment. Perpetual care (currently used) appears to be the best decommissioning alternative for these burial grounds at this time. However, another alternative may be selected depending on future waste management policies, plans, or activities