Four jib cranes have been installed in a complex operation at the Hanford vitrification plant's Low Activity Waste Facility, Bechtel National announced.
The cranes, each with a capacity of three tons, will be used to place lids on containers of glassified waste at the end of the waste treatment process. The lids will be added in the southeast corner of the building, commonly known as the "finish line."
The $12.2 billion plant will separate Hanford's radioactive and chemical waste now held in underground tanks into low-activity and high-level waste streams, then turn them into a stable glass form for disposal.
A team of vit plant employees worked together to develop a rigging and installation plan that allowed the cranes to be safely moved through doorways and into the finish line area, then anchored into place.
The plan included carefully rotating the 12-foot-long cranes vertically and horizontally within tight spaces multiple times during the installation process. The finish line area measures 15 feet wide, 12 feet tall and 110 feet long.
Rotations were done using chain hoists that were manually operated. A specially designed cart also was used to transport the cranes within the area.
The cart, which runs on permanently installed rails, continues to be used for equipment installations in the finish line area. The rails will be used to transport the filled low activity waste containers when the facility is operating.
"These were very challenging installations that required careful and detailed planning," said Joe Jacoby, assistant area superintendent for the facility, in a statement. "The cranes not only needed to be rotated to get into the area, to maintain a center of gravity on the car and to be transported, but they were designed to fit so close to the ceiling that conventional rigging would not work."
The work required extensive collaboration between union workers, field engineers, rigging engineers and supervisors, he said.
The crane sits just six inches from the ceiling and required workers to use special low-headroom rigging attachments and customized short rigging components.
"The jib cranes had to be installed before we could install the major equipment in the finish line area," Gary Olsen, Department of Energy area project manager, said in a statement. "Now, we can install the equipment -- such as the decontamination robot and the lidding arms -- that will prepare filled containers for removal from the (building)."