Kennewick builder wins $11.3M Hanford contract

Apollo Inc. of Kennewick has been awarded an $11.3 million subcontract to prepare the Hanford building sitting above a highly radioactive spill for the installation of cleanup equipment.

The spill – which is so radioactive that the Department of Energy says it would be lethal within two minutes of contact – will be dug up with remotely operated equipment mounted inside the building.

The 324 Building is about a mile north of Richland and 300 yards west of the Columbia River. While most buildings in the area have been demolished, it has been left standing to shield workers from radiation and prevent precipitation from seeping into the soil and spreading the highly radioactive cesium and strontium.

Apollo’s tasks for CH2M Hill Plateau Remediation Co. will include removing old equipment and wiring from the walls of hot cells and drilling holes in the walls for later installation of remotely operated cleanup equipment.

Hot cells are thick-walled rooms where workers used remotely operated equipment to perform work with highly radioactive material.

“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 Building Disposition Project.

Apollo also is preparing some hot cells to be filled with concrete-like grout once the contaminated soil is dug up. It will cover and seal holes in the walls where wires and piping passed through to keep the grout from oozing out.

The contract also includes designing, building and demonstrating a remotely operated tool for cutting piping in the hot cells, as well as modifying the building’s foundation to ensure stability during soil removal.

Apollo is expected to begin making modifications to the 324 Building hot cells in the coming weeks and will work through most of 2018.

The spill was discovered in 2010 as workers prepared the building for demolition.

The spill is suspected of resulting from work in B Cell in the 1980s. Workers were fabricating concentrated cesium and and strontium into a heat source for Germany to test a repository for radioactive waste, which emits heat.

The material likely made its way through the cracked lining of a sump at the bottom of the cell.

The high level of radiation from the spill has ruled out conventional methods of digging up the soil contaminated by the spill.

The revised plans call for installing remotely operating equipment on the walls of B Cell to cut through the floor, dig up the contaminated soil and load it out. The most contaminated soil will be placed in boxes in other hot cells and grouted for removal when the building is demolished.

CH2M workers are continuing to remove radioactive debris from the building’s airlock to allow easier access to the building’s highly contaminated hot cells. Work also is continuing at a mock-up of the project that will be used to demonstrate remotely operated equipment and train operators before the equipment is installed at the 324 Building.

Removal of the contaminated soil is expected to begin in 2019.