Topographical Mapping System. Tanks Focus Area. OST Reference # 130

Abstract

Radioactive waste storage tanks in use at many of the U.S. Department of Energy (DOE) sites are beyond the intended design life. The waste in these tanks must be remediated and the tanks closed. Before these activities are performed, the physical condition of tank interiors must be determined along with detailed information regarding any obstructions and potential problems that may be encountered during installation of retrieval systems. This task is difficult because the tanks are underground and have limited access. The only way to see the physical contents of the tank is to install tools through the tank’s openings, or risers. The Topographical Mapping System (TMS), a three-dimensional (3-D) mapping system that can safely operate in hazardous and radiological environments, has been developed to meet this need. This system provides an accurate 3-D view of the tank interior and gathers data on volume and contents inside storage tanks. How It Works: TMS is self-contained and reconfigurable system capable of providing rapid, variable-resolution mapping information in poorly characterized workspaces with a minimum of operator intervention. TMS uses structured light to create maps of waste topography and tank structures, determine surface features and deviations, model the tank environment, and determine residual tank waste volume. The system gathers and analyzes data to generate 3-D maps. The data can be used on a stand-alone basis or integrated with other modeling software to generate “world models” of tanks or other work environments. Figure 1 is a time-lapse photograph of the contour lines that result when the laser planes intersect with the mapped surface. The simulated waste surface in the photograph contains sand, simulated saltcake (white rock), and two black vertical pipes.