White Shield provided detailed topographic surveys and subsurface investigations for these three nuclear waste tank farms at the Hanford Nuclear Reservation. The principal function of the tank farms is the safe interim storage of highly toxic byproduct material left over from plutonium extraction operations. This material is stored in 177 single-shell and double shell underground storage tanks with a cumulative total capacity of 55 million gallons. This project required highly detailed topographic maps of different tank farms sites as completely and accurately as current technology allowed. The surveys were used for the development of accurate crane route maps that will support future maintenance and remediation efforts.
Control surveys were performed for the recovery and verification of existing published control points. Surface elevations were measured to define contours at 0.5-foot intervals. All above ground features were captured in the detailed 2D planimetric data which included paved surfaces, vegetation, fences, walkways, visible surface indications of underground utilities (i.e. manholes, valve boxes, fire hydrants, electrical junction boxes, etc.), culverts (type and size), any other permanent structures, and power poles with noted low-wire elevations (at pole and sag). Horizontal and vertical locations were accurate to ±0.10’.
White Shield utilized a Leica ScanStation C10 pulsed dual-axis compensated High Definition Scanner (HDS) rated at 50,000 points per second, with proven accuracies on some shorter range scans to 1/32͟. Full-dome survey data, and photography with the use of the on-board digital camera, was captured for future use in locating overhead power lines and other features. In addition to the exceptional level of detail captured, the use of HDS provided an additional measure of safety in enabling crews to gather data from outside fenced areas, eliminating possible exposure to radiological or contaminated areas. A detailed work plan was in place prior to beginning this work, which also limited exposure and eliminated the need for returns trips to the project site.
Ground Penetrating Radar (GPR) was utilized to map the location of below-ground utilities, pipes, and other obstructions and was included in the final drawings. Digital base mapping was provided in AutoCAD Civil 3D format.