Nine years of preparation paid off this week as Hanford workers moved the first of the highly radioactive sludge out of the K West Reactor Basin not far from the Columbia River.
"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," said Doug Shoop, manager of the Department of Energy Hanford Richland Operations Office.
The K West Basin is 400 yards from the river.
Late Tuesday afternoon CH2M Hill Plateau Remediation Co. workers transferred the first batch of sludge out of underwater containers in the K West Basin into a storage container inside a shipping cask at an annex built nearby for the transfer.
"It went flawlessly — without a hitch," said Mark French, DOE project director at the Hanford nuclear reservation.
The work actually went better than expected, said Ray Geimer, vice president of K Basin operations for CH2M.
In the planned 13-minute-long transfer, Hanford officials had expected to remove 200 to 300 pounds of sludge from the basin. Instead, the transfer moved 650 pounds, he said.
The first of an estimated 18 to 24 filled containers, each 10 feet tall, is expected to be trucked the 12 miles to Hanford's T Plant in the center of the site the week after next.
The containers will be stored in below-ground cells until they can be prepared for disposal. The cells were once used as part of the process to remove plutonium from irradiated fuel at T Plant.
The project was expected to cost $311 million, but is $20 million under budget, French said.
The sludge is highly radioactive because it contains particles of deteriorated irradiated fuel that was not processed to remove plutonium at the end of the Cold War.
Instead the fuel was stored in the water-filled cooling basins attached to the K West and K East reactors. Before the fuel was removed in 2004, it corroded underwater and fuel corrosion particles, metal fragments and dirt combined to form sludge.
About 950 cubic feet of sludge accumulated in the basins.
After getting the sludge into underwater containers and the sludge from the K East Basin consolidated into the K West Basin, work began in 2009 to get the sludge moved to dry storage away from the river.
A mockup of the K West Basin pool and the sludge transfer annex were built inside Hanford's Maintenance and Storage Facility, or MASF.
Equipment designed for the sludge transfer was tested at the facility and workers were able to practice using the tools and the procedures repeatedly.
"I'm pleased with the amount of planning, training and engineering that has gone into this sludge transfer," said Rod Lobos, an environmental engineer with the Environmental Protection Agency, a Hanford regulator.
"So far, so good," he said. "I hope that continues."
Legal deadlines for starting the transfer of sludge have been repeatedly reset. But the start of sludge transfer on Tuesday easily meets the current deadline set three years ago to start the transfer by September of this year.
After each batch of sludge is pumped from the K Basins, the storage container will be left to sit for at least two hours for solids to settle.
Then some water will be removed from the container to make room for the next batch of sludge. The sludge is mixed with up to 95 percent water to allow it to be transferred through pipes to the annex.
Because the sludge is so radioactive, the filled containers must contain several feet of water to shield workers from radiation as they disconnect the sludge transfer hoses from the filled containers.
Disconnecting the hoses and other steps to prepare filled containers for transport pose the most risk to workers and will be done in a disciplined manner, Geimer said.
"When dealing with contaminated equipment and (radioactive) dose rates we wanted to get everything right," French said. "Now it's the real deal."
Once at T Plant, the tractor trailer holding the sludge container will be backed into a tunnel, allowing the container to be placed in a cell that has leak detectors and a catch pan ready in the unlikely event of a leak, according to DOE.
DOE has a legal deadline to have all the sludge moved to T Plant by the end of 2019 and then must have a treatment and packaging plan for disposal of the sludge selected by 2022.
Risks will remain at the K West Basin after the sludge is gone, Shoop said.
Highly contaminated water filters in the basin must be removed, along with a large amount of contaminated equipment submerged in the basin water. The 1.2 million gallons of contaminated water in the basin also must be processed.
Eventually the basin will be filled with grout and then the pieces of grout cut out for disposal, as has already been done at the nearby K East Reactor Basin.