The creation of a new tool has moved the Savannah River Site's liquid waste contractor a step closer to closing some of the tanks holding nuclear waste.
A team led by Construction Superintendent Tony Smith and Discipline Engineer Beau Nichols invented a tool to remove obstructions that could have prevented the installation of a mixing pump used for waste removal and tank closure, Savannah River Mission Completion announced recently.
Jim Folk, the Department of Energy Savannah River Office assistant manager for waste disposition, said clearing the access riser was an important step for continued treatment of nuclear waste.
The Savannah River Site produced plutonium and tritium during the Cold War. During this process, nuclear waste was generated and stored in underground tanks in H- and F-Areas of the Savannah River Site. The Department of Energy is in the process of disposing of the nuclear waste held in these tanks.
"Successful waste removal is the first step toward operational closure of a liquid waste tank," Folk said. "This tank is one of several that is entering final stages of removal from use, and this creative solution helps the tank remain on its path to closure."
The new tool is a disc grinder with a diamond grit coating that is attached to a 20-foot steel tube, Nichols said.
Both Smith and Nichols were supported by pipefitters, the radiological protection group and the inspection and monitoring team. The groups developed, tested and perfected the tool and its use though several mock-up evolutions.
Workers use the tool to remove obstructions in the tank top opening, which is also known as a riser, according to a news release. The obstructions include welding material left over from the installation of equipment in the tank in the 1970s, the release continued.
Without the tool, workers would be unable to install a mixing pump to facilitate the emptying and closing of the tanks.
The tool uses "guide bars on one end to prevent the disc from grinding too deeply into the riser, as well as some modifications that allow the grinder to be operated by workers who must stand at a safe distance," Nichols said.
The tool is suspended overhead from a crane and is secured at the riser opening to maintain a consistent elevation for the grinding.
Pipefitters in a protective hut were able to view their work on a closed-circuit TV monitor , while live video was provided by a camera attached to the tool just above the grinder. The superintendent and radiological protection personnel also viewed the video feed in a nearby command trailer while providing guidance through radio communication.
