Within the Office of Science and Technology, the Robotics Technology Development Program helps OST incorporate robotics into integrated systems for cleaning up contaminated Department of Energy sites. Remotely controlled, rugged manipulation systems are particularly important to the Tanks and the Deactivation and Decommissioning focus areas because robots can perform in DOE's high-level storage tanks and hazardous/radioactive facilities—places that expose humans to unacceptable risks.

Robotic system cleans radioactive Oak Ridge tanks
OST's Robotics Technology Development Program has supported the development of two robotic technologies—Houdini and the Modified Light-Duty Utility Arm—that, as part of the Radioactive Tank Cleaning System at the Oak Ridge National Laboratory in Tennessee, are continuing to play important roles in the cleanup of Oak Ridge's gunite tanks. Houdini is a remotely controlled (through a tether), hydraulically powered, folding vehicle that can pass through 24-inch openings in tanks called risers and then open to a 4 x 5 foot minibulldozer, complete with a plow blade; a dexterous, high-payload manipulator; and remote camera system.

The Modified Light-Duty Utility Arm is a large, robotic manipulator with seven degrees of freedom. It can deploy a 200-pound payload through risers as small as 12 inches in diameter. The MLDUA is equipped with a gripper end-effector that allows the arm to grasp other tools such as the Confined Sluicing End-Effector. The MLDUA is also equipped with two cameras located at the mast and arm junction and an additional camera in the gripper. It is skid mounted so a crane can position it on the tank platform where it rests on adjustable outriggers. A second skid contains the hydraulic power unit, oil reservoir, pumps, oil chiller, and controls cabinets.

In addition to Houdini and the MLDUA, the Radioactive Tank Cleaning System also includes the Confined Sluicing End-Effector, which dislodges waste with its high-pressure water jets (10 gallons a minute of water at 7,000 pounds per square inch). CSEE is equipped with handles that can be grasped by the MLDUA and Houdini for positioning within the tank. The Hose Management Arm carries dislodged waste from the tank through its transfer hose.

The project
The Gunite and Associated Tanks Operable Unit at Oak Ridge contains 16 tanks of various sizes, a majority of which are in two areas—the North Tank Farm and the South Tank Farm. Constructed during the 1940s, 12 of the 16 underground tanks were made with the gunite process, in which a cement and sand mixture was sprayed on a wire mesh and reinforcing rod frame. The tanks have been taken out of service due to their age and uncertain condition.

Gunite tank cleanup began in July 1997 and has resulted in the removal of mixed transuranic waste from two gunite tanks—W-3 and W-4 in the GAAT North Tank Farm. Houdini has participated by shoveling waste with its plow; manipulating the CSEE; and using other end effectors to cut and remove in—tank debris, obtain core samples, and perform characterization and inspection tasks. Houdini has proved that it can even operate while hanging, which was the case when the remotely controlled robot cut and removed cables and steel pipes while hanging below manways in tank W-3.

The MLDUA and Houdini have worked well together in the gunite tank cleanup. The plow on Houdini pushed sludge toward the MLDUA and accumulated piles of sludge to be sluiced. The MLDUA has worked best for removing thicker piles of sludge, while Houdini is better at cleaning floor surfaces. A coring tool deployed by Houdini obtained core samples. The walls were cleaned with the MLDUA and CSEE at 7,000 psi. This scarifying action removed loose contamination and much of the scale on the walls. During wall cleaning, a dense fog developed in the tank, limiting visibility. The ability to preprogram robotic trajectories for the MLDUA enabled wall cleaning without fear of collisions with the tank walls or floor. After scarifying, a characterization end-effector confirmed that radioactivity in the walls was reduced by approximately 20 percent.

Approximately 12,600 gallons of waste was removed from tank W-3 during the 10-week waste removal campaign that began in July 1997. Less than 0.3 percent of the original tank volume remains—sludge and liquid heel. The Radioactive Tank Cleaning System removed an estimated 331 Ci of the original 344 Ci present in tank W-3, i.e., more than 96 percent contaminant removal efficiency.

Successful partnering
The gunite tank cleanup project at Oak Ridge exemplifies how multiple organizations can work together to successfully accomplish cleanup of a DOE waste stream while realizing significant schedule and cost savings. RTDP worked with other OST organizations—Industry Programs (coordinated by the Federal Energy Technology Center in Morgantown) and the Tanks Focus Area—to develop Houdini in response to user requirements. The private-sector partners are RedZone Robotics, Inc., a small business in Pittsburgh that manufactures Houdini, and Spar Aerospace in Toronto, which manufactures the MLDUA. The DOE Office of Environmental Restoration (EM-40) user, in this case, is the Oak Ridge gunite tanks remediation contractors, who specified technical needs for remediation. Collaboration among users (EM-40) and developers (OST, or EM-50) within DOE's Office of Environmental Management allowed both organizations to leverage resources and share benefits. DOE Oak Ridge Operations enjoyed major cost and schedule savings, while OST accelerated the field deployment of waste removal equipment, thereby providing equipment and information useful to other DOE tank sites at the Hanford Site in Richland, Washington; the Savannah River Site near Aiken, South Carolina; and the Idaho National Engineering and Environmental Laboratory near Idaho Falls, Idaho.

On to new gunite tank challenges
The hot test operations in the less contaminated tanks of the North Tank Farm (tanks W-3 and W-4) provided confidence that the same operations could be performed safely and effectively in the gunite tanks in the South Tank Farm. After completing cleanup of tanks W-3 and W-4, waste removal operations were initiated in tank W-6 in April 1998. Waste will continue to be removed from the remaining Gunite and Associated Tanks and transferred to a temporary storage tank through the end of FY 2000.

For a more detailed account of the cleanup of gunite tank W-3 at Oak Ridge, see Radwaste Magazine, March 1998, pages 55–61.

Robotics and the D&D Focus Area
The Robotics Technology Development Program provides robotic expertise to the Deactivation and Decommissioning Focus Area's large-scale demonstration and deployment projects. RTDP also lends it expertise and, along with Industry Programs, works with university and industry robotics researchers to solve challenges faced by DDFA. Among the robotic technologies with potential to cut the risks and costs of using humans to deactivate and decommission hazardous and radioactive facilities are the following:

BOA (Asbestos Pipe Insulation Removal System) is a mobile, pipe-external robotic crawler for remotely stripping and bagging asbestos-containing lagging and insulation material from pipes. It was featured in Initiatives, June 1997. Since then, BOA has undergone its first field demonstration at the East Tennessee Technology Park and has been winning rave reviews. The robot placed second in a national design competition hosted by Design News and in March was showcased at the annual National Design Engineering Show and Conference in Chicago. The low productivity and high cost of manual asbestos removal make this mechanical system a cost-effective component of D&D activities across the DOE weapons complex.

During FY 1998, researchers at Carnegie Mellon University in Philadelphia continued their BOA work. The system has been modified to fit a 3-inch-diameter pipe, and the electronic control box has been refurbished with higher voltage components. The next step for BOA is a full-scale field test at a DOE or private industry site.

RoboCon (Operator Interface for Robotic Applications) is a robot operator control station that is designed to be adaptable to a variety of remote and robotic selective equipment removal systems. It is being developed by researchers at Carnegie Mellon University and Oak Ridge National Laboratory. The system consists of a large, multiscreen projection TV system framed on both sides by several high-resolution TV monitors, embedded computing, stereo speakers, and a reconfigurable operator console and control chair with various removable interface modules (such as joysticks, buttons, and touch-screens). CMU demonstrated RoboCon at its Pittsburgh facility using the Houdini robot also developed by CMU. Houdini was remotely operated from the console to showcase different features of the system. RoboCon has been installed at the International Union of Operating Engineers' training center in Beaver, West Virginia, where it will undergo a human factors and ergonomic analysis.

Three-Dimensional, Integrated Characterization and Archiving System (3D-ICAS) was demonstrated at Oak Ridge National Laboratory's Robotics Technology Assessment Facility in October 1997. Developed by Coleman Research Corporation and jointly sponsored by RTDP and Industry Programs, 3D-ICAS consists of a mobile sensor platform and a mobile mapper platform that operate in contaminated areas, and an integrated workstation that remains in a safe area. Capable of detecting organic compounds at the parts-per-billion sensitivity level while simultaneously measuring alpha and beta radiation on structural materials, the system operates without contacting the surface of interest by deploying a robotically controlled sensor head. The cycle time for 3D-ICAS is less than two minutes per sample.

The Robot Task Space Analyzer will be a sensor and software system that allows robot operators to automate robotic tasks. Combining laser and stereo imaging, human-interactive modeling, and semiautomatic object recognition, RTSA will help human operators quickly and efficiently create three-dimensional models of the work environment in which a robot operates.

Hanford canyons: From liability to asset?
Can five large chemical processing facilities (canyons) at Hanford's 221-U plant be cost-effectively converted to storage facilities for low-level waste? Will the cost of conversion be more than offset by the avoidance of long-term surveillance and monitoring costs? These questions are the focus of the Hanford Canyon Disposition Initiative, a partnership among DOE's offices of Environmental Management—Waste Management (EM-30), Environmental Restoration (EM-40), Science and Technology (EM-50), and Nuclear Material & Facility Stabilization (EM-60).

The robotics program is assisting the Deactivation and Decommissioning Focus Area because much of the HCDI project will have to be performed remotely due to access constraints and contamination levels. In FY 1998, RTDP will help the users define robotic needs and select appropriate technologies to characterize the facility. If the decision is made to convert the facility to a storage site, RTDP will help select technologies to prepare the building for conversion.

HCDI is part of a CERCLA remedial investigation/feasibility study on the costs and risks of alternatives for the disposition of the chemical reprocessing canyons, including use as a low-level radioactive waste disposal facility. Extensive characterization is required to complete a performance/risk assessment, which in turn will lead to a Record of Decision in FY 2000.

Using Hanford's five canyon facilities for disposal of low-level wastes has the potential to save more than $1.1 billion over the current baseline of long-term surveillance and maintenance followed by complete facility D&D. Besides Hanford, the potential use of fuel processing facilities for waste disposal also has application to three facilities at DOE's Savannah River Site and one facility at Idaho Falls.

Current RTDP involvement in the HCDI project includes

• conducting a needs analysis to determine appropriate robotic technologies for characterizing the canyons and converting them into storage facilities, and
• adapting an off-the-shelf, commercially available robot for surveying a railroad tunnel.

The railroad tunnel-characterization task has begun, using Andros, an 18-inch-wide, tethered robot that is owned by Pacific Northwest National Laboratory. RTDP in collaboration with Pacific Northwest National Laboratory fitted Andros with a radiation sensor and a video camera. In June and July 1998, the sensor was integrated with Andros and operational testing and a readiness review were completed. In August, a crane placed Andros in the tunnel, and the robot began gathering radiation data. PNNL staff are also considering using Andros to deploy a rotating-drum smear-sampling unit within the railroad tunnel. Andros will next be used to characterize a ventilation tunnel.

For more information on RTDP's role in HCDI, contact Dennis Haley, robotics coordinator for HCDI, at Oak Ridge National Laboratory, (423) 576-4388, haleydc@ornl.gov. For more information on RTDP, contact Linton W. Yarbrough, Ph.D., RTDP field office lead, at the DOE field office in Albuquerque, (505) 845-6569, lyarbrough@doeal.gov.