CH2M Hill clears first-of-a-kind waste retrieval milestonePosted: Updated:
RICHLAND, WASH. – August 9, 2010 – U. S. Department of Energy (DOE) contractor CH2M HILL Plateau Remediation Company (CH2M HILL) recently completed retrieval of highly radioactive waste from Settler Tubes in Hanford's K West Basin, located approximately 400 yards from the Columbia River at the Hanford Site in Washington State.
The activity supports DOE's sludge treatment project, one of the nation's highest environmental cleanup priorities.
"Capturing the sludge from the settler tubes in the 100-K West Basin will pave the way for complete sludge removal and supports DOE's vision of completing cleanup along the Columbia River by 2015," said Matt McCormick, Manager of the DOE Richland Operations Office.
CH2M HILL retrieved 3.5 cubic meters of radioactive material from 10 separate 16-foot-long horizontal settler tubes located underwater in the K West Basin. Settler tubes were part of a system used to clean sludge off spent fuel before it was moved out of the basin.
Small portions of the retrieved material will be sent in protective lead-lined containers to the Pacific Northwest National Laboratory for characterization. The results will help engineers optimize the design of systems to remove the sludge from the basin and transport it to a facility for interim storage, as well as determine the best method for treating and packaging the sludge.
"Retrieval of this waste allows us the opportunity to complete sampling and determine the best method for treatment and removal of the sludge," said John Lehew, CH2M HILL President. "This is a key milestone toward final retrieval of the sludge from the Engineered Containers in the basin and ultimately meeting DOE's goal to get it away from the river."
In 2009, workers collected samples of sludge from four stainless steel containers on the floor of the K West Basin. Sampling of the sludge in the remaining two containers is expected to be complete this year.
Sludge Treatment Project (STP) engineers and technicians spent more than two years designing and testing tools to safely complete this first-of-its-kind retrieval.
Using a mock-up of a settler tube at the 400 Area Maintenance and Storage Facility, workers practiced removing the material with the same tools they would later use to remotely retrieve the actual sludge. Once the process was perfected, operators and radiological control technicians, dressed in layers of radiation-protection clothing and respiratory equipment, used 22- to 25-foot-long tools to remotely reach down through grating and water to reach the settler tubes in the basin.
"Sampling the sludge supports characterization and will provide a higher level of confidence when we treat the sludge," said Lehew. "Our team was successful in retrieving the waste safely, ahead of schedule and below cost."
Prior to the start of cleanup, the water-filled K East and K West Basins held approximately 2,300 tons of spent nuclear fuel and radioactive sludge – a combination of dirt, sand, corrosion products, sloughed concrete from the basin walls, and/or fission products that formed during years of storing the spent fuel underwater.
Workers finished moving the spent fuel out of the basins in 2004 and finished consolidating the highly radioactive sludge from the floors of both basins into engineered stainless steel containers in the K West Basin in 2007.
These new, safer containers provide a secondary barrier to the environment.
STP engineers are currently designing the systems and components necessary to retrieve the sludge from these containers and transfer it to a more secure interim storage facility on the Central Plateau.