Final results of the application of a structured light source for surface mapping in the Fernald K-65 silos

During 1991, a remotely operated surface mapping measurement system was developed at Oak Ridge National Laboratory for use in the K-65 waste storage silos at Fernald, Ohio. Preliminary reports have been presented discussing the planned development project and intermediate results. In this report the authors discuss the sensor system development and present the final results of the hot deployment. The K-65 silos are above-ground, domed, concrete and reinforced steel structures built in the early 1950s to store uranium residue from the Feed Materials Production Center (FMPC), Fernald, Ohio. Two of the four silos contain a waste material that is rich in radium content and, hence, generate large amounts of radon gas. During the fall of 1991, a layer of bentonite clay was deposited over the entire waste surface in silos 1 and 2. This bentonite layer was placed to act as absorber to capture the emitted radon gas. We describe the application of a structured light source to obtain waste surface contour data before bentonite deposition and to obtain bentonite surface contour data after deposition. The thickness of bentonite at any point along the waste surface can be determined by the change in surface height. Development of this technology andmore » cold testing in silo 4 was sponsored by the DOE Environmental Restoration and Waste Management Office of Technology (OTD) while hot deployment was sponsored by the DOE Office of Environmental Restoration.« less