Workers at the Hanford Site in Washington state successfully transferred the first batch of highly radioactive sludge out of underwater storage in the K West Reactor Basin late Tuesday afternoon. The Department of Energy had a Tri-Party Agreement deadline, reset most recently in 2015, to start removing sludge from the basin by the end of this fiscal year.
Workers have been preparing for the transfer since 2009, following the consolidation of the sludge from underwater containers in the K East Reactor Basin into the K West Reactor Basin. The sludge was the result of irradiated fuel that was stored in the K Reactor basins at the end of the Cold War rather than being processed to remove plutonium. Before the fuel was removed from the basins in 2004, it degraded and mixed with dirt in the pools to form 35 cubic yards of sludge. The sludge contains fuel corrosion particles, bits of metal, and dirt.
“The sludge is some of the most hazardous material at Hanford, so moving it away from the river to safe storage in a robust engineered facility in the center of the site significantly reduces risk,” Doug Shoop, manager of the DOE Hanford Richland Operations Office, said in a statement Wednesday.
The 13-minute initial transfer Tuesday went better than expected, said Ray Geimer, vice president of K Basin operations for cleanup contractor CH2M Hill Plateau Remediation Co. CH2M had anticipated moving 200 to 300 pounds of sludge in a slurry that was 95 percent water in the first transfer. But workers were able to move a mixture of up to 14.5 percent solids through shielded transfer lines from the basin to the annex to get 650 pounds of solids moved in the initial transfer.
Plans call for allowing solids to settle in a transport and storage container inside the annex after each transfer. Then some excess water can be removed and more sludge added to the container. The first container is expected to be trucked 12 miles to T Plant in central Hanford the last week of June. About 18 to 24 containers, each 10 feet tall, are expected to be filled and transported to T Plant. They will be stored in the plant’s below-ground cells.
The Energy Department is required by the Tri-Party Agreement to have all the sludge transferred to T Plant by the end of 2019.
