Description
The Light Duty Utility Arm System (LUAS), also called the Robotic Tank Characterization System (RTCS), provides a remotely operated, mobile system to deploy end effectors (robotic tools) for waste characterization and tank inspection. This technology will enhance existing capabilities that are limited to single-axis instrument deployment. The current means for performing tank inspection and waste characterization consist of vertical deployment of cameras, instruments, and sampling instruments through risers (openings) on fixed supports. These systems are limited to operation directly below the tank penetration riser.
In contrast, LUAS provides a robotic arm with six degrees of freedom that can position itself at any point within a 9-ft radius hemisphere of the penetration riser. The robotic arm system is designed for deployment through a 12-in. diameter tank riser and reachs to a depth of 48-in. below the waste surface. The robotic arm system will not be able to provide full depth penetration, but it will be able to maneuver other equipment (50-100 lb) above the waste source and provide multiple position samples taken within a 9-ft radius of the riser. LUAS enables some waste characterization, in-tank surveys, and waste topography activities to be performed in-situ to gather data on chemical and physical properties of the waste and information on the structural condition of the tanks. This will not replace laboratory analysis; however, it will provide the capability to gather data in multiple locations within a tank much faster than do current core sampling and laboratory analysis programs.
LUAS consists of various interfaces including an man/machine, graphical user interface; a standardized utility-arm/end-effector interface, called the Tool Interface Plate; and a utility-arm/tank-riser interface for containment. The characterization process would begin by installing the tank riser interface, which includes a containment enclosure. The LUAS mast would then be placed inside the containment enclosure and an appropriate end effector installed. At this point, the mast would be lowered into the tank. The robotic manipulator would be subsequently deployed out of the mast to initiate the characterization or nspection campaign. Data would then be transmitted to data acquisition stations, analyzed, and archived.
Upon completion of data collection, the mast and arm would be retracted out of the tank through a decontamination spray (a pelletized carbon dioxide blast) that removes surface contamination from the mast, manipulator, and end effectors. The pressurized spray decontamination system is mounted just above the tank riser inside the containment vessel.
The graphical user interface can be operated by a single specially trained technician. The graphical control interface includes supervisory control of the robotic system to ease operator fatigue. LUAS also provides a Standard Tool Interface Plate for multiple characterization and inspection end effectors.
Technical Performance
Design. LUAS was designed with a 9-ft multidirectional reach with 6 degrees of freedom of motion. The entire utility arm and end effector was designed for deployment through a 12-in. diameter access riser. It will support instrumentation end effectors that weigh less than 100 lb. As low as reasonably achievable (ALARA) principles were applied to LUAS to minimize human exposure to hazardous environments. The design includes a pelletized carbon-dioxide blast system for high-pressure spray decontamination during retraction.
Laboratory Testing. Detailed reliability analysis is part of the design verification process. Kinematic redundancy analysis has been performed on LUAS to indicate the potential failure modes of the configuration of vendor-proposed designs and to determine whether minor modifications could result in improved performance and reliability. The analytical technique was developed under the Cross Cutting and Advanced Technologies University Program. The results of this analysis have not yet been made available for publication.
Costs. Start-up, operations, and maintenance costs are currently being determined and are not available at this time.
Projected Performance
The system is planned for cold testing in FY95 and for a hot testing demonstration in FY96 in the actual radioactive waste environment of a Hanford Underground Storage Tank. Detailed performance and projected performance information will be available after the cold test in FY95.
Waste Applicability
This technology is applicable for remote visual inspection of underground storage tank structural conditions. It is also applicable to extract multiple core samples over the lateral positional range (varies with waste level) inside a tank to a maximum penetration depth of 4 ft. The robotic arm would support other chemical and physical property instrumentation tools for in situ characterization of hazardous and radioactive wastes, provided that the total weight of the end effector instrument is less than 100 lb.
Status
LUAS is currently in the laboratory testing evaluation and refinement phase of development. Hazards, operability, and regulatory studies are scheduled for late FY93. The system consists of a mix of off-the-shelf and Office of Technology Development developed hardware and software. Development of a complex robotic system is part of this effort.
Regulatory Considerations
To meet potential regulatory considerations, LUAS includes the pelletized carbon-dioxide blast decontamination system and a containment vessel mounted above the access riser. Clean Air Act requirements are applicable to the containment vessel. Minimal environmental impacts are anticipated from the use of this characterization technology. A detailed regulatory and worker safety analysis will be completed in late FY93.
Potential Commercial Applications
Potential commercial applications are in the nuclear power industry for Nuclear Regulatory Commission compliance reactor safety inspections, for hot storage tank and spent fuel rod inspection, and for reactor decontamination and decommissioning.
Baseline Technology
The baseline technology is deployment of cameras, instruments, and waste samplers through risers on fixed supports with their operation limited to vertical-axis motion directly below the riser.
Intellectual Property Rights
Patents: None
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References
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