CH2M Hill Plateau Remediation Co. has awarded an $11.3 million subcontract to prepare for installation of remotely operated equipment to clean up the highly radioactive spill beneath the Hanford Site’s 324 Building.
The subcontract went to Apollo Mechanical Contractors, headquartered in Kennewick, Wash., near Hanford. Apollo is expected to begin work in the next few weeks and continue through most of 2018.
Removal of the soil contaminated by the spill is scheduled to begin in 2019.
“We’ve advanced the project to the point we’re actually about to begin making the necessary modifications to the building to allow us to install equipment that will be used to remove the radioactive soil under the building,” said Mike Douglas, acting vice president for CH2M’s 324 Building Disposition Project.
Workers were preparing to demolish the former Chemical Materials Engineering Laboratory in 2010 when a spill of concentrated cesium and strontium was found underneath. The contamination likely was from hot cell operations in the 1980s, when waste from Hanford tanks spilled within the building’s B Cell and passed through a cracked lining of a sump at the bottom of the cell.
Officials revised plans to leave the building standing to shield against radiation and prevent water from infiltrating the waste beneath it while contaminated soil was dug up with remotely operated equipment mounted in B Cell. The soil will be placed in boxes in other hot cells in the 324 Building for grouting.
The Apollo Mechanical Contractors subcontract includes removing old equipment and wiring from the walls of the hot cells and drilling holes in the walls for later installation of remotely operated equipment. Apollo also is preparing the hot cells to be filled with grout after contaminated soil is removed. It is covering and sealing holes in the walls where wires and piping passed through. The holes must be filled to keep grout from leaking out of the hot cell. The contract also includes designing, building, and demonstrating a remote-operated tool for cutting piing in the hot cells, as well as modifying the building’s foundation to ensure stability during soil removal.
Editor’s Note: An earlier version of this article identified the subcontractor as Apollo Inc., which shares a majority owner with Apollo Mechanical Contractors but is a separate corporate entity.
