Nuclear Waste
Team Boosts Radioactive Waste Removal from Underground Tanks at DOE Hanford Site
Cleanup at the U.S. Energy Dept. 560-sq-mile Hanford nuclear waste site in eastern Washington state entered a new phase as its expands removal of 56 million gallons of radioactive and chemical waste long stored in leak-prone underground single-shell tanks and integrates a just-agreed-to treatment and disposal approach.
In August, site contractor Hanford Tank Waste Operations and Closure, a joint venture of BWXT, Amentum and Fluor Corp., completed a 79,000-gallon waste retrieval from one tank and performed a complicated pump removal in another to propel the waste removal, treatment and disposal effort. Its 10-year, $45-billion contract in effect since 2024 includes design, construction and operation of tank farm facilities and operation of the new site waste vitrification plant, which came on line last year.
To date, about 3.5 million gallons of waste have been removed from 24 of Hanford’s 149 single-shell tanks, with the 25th tank operation to start in October. DOE is legally mandated to remove all waste from single- shell tanks for double-shell tank storage or direct treatment by 2040. Work pace is hindered because the more protective but fewer in number double-shell tanks are near maximum capacity. The total of 177 tanks were built to hold Hanford waste generated from production of 74 tons of plutonium for the U.S. nuclear weapons program from 1944 to 1989.
The waste is set to be turned into inert glass through the vitrification process for which DOE spent 20 years developing, an onsite industrial-capacity treatment plant built by Bechtel, with technical and logistical challenges. It was estimated to cost about $20 billion as of 2025 when the agency began treatment of tank waste with low levels of radioactivity. The process for high-level waste is mandated to start in 2033.
Tank Pump Gets Lifted
To expedite moving wastes to the plant, Hanford Tank Waste Operations and Closure needed to remove from one double shelled tank a 10-ton, 50-foot-long pump installed in1993 because to reduce hydrogen buildup in stored waste at the time. It no longer has a purpose and physically obstructs the tank opening so next-generation waste retrieval equipment cannot be installed.
“This project was important because it safely removed a large, specialized piece of equipment that had served its purpose and was standing in the way of future work,” says Andy Wiborg, director of DOE’s Hanford field office tank farm programs division.
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The contractor team used mock-up training and custom engineering before work began, rehearsing the removal offsite. Its custom-designed Hercules hydraulic lift system helped free the pump in a controlled manner while other systems cleaned, handled and packaged the pump for disposal. Before the operation, crews conducted hands-on training and equipment testing at DOE Hanford subcontractor HiLine Engineering & Fabrication in Richland, Wash.
“The size, weight and installation location contributed to the challenge,” says Dustin May, Hanford Tank Waste Operations and Closure project manager. “We designed a lot of specialized equipment to remove the pump in phases, which included multiple size-reduction steps and a preliminary heavy lift to break free the pump from its installed position.”
The team ensured no liquids remained inside the pump, requiring drainage. “To do this, we designed and deployed a robotic multi-tool device that could drill, hole punch, shear and roto root the pump as it was removed from the tank,” says Peter Griffin, contractor project engineer. “This allowed the free liquids to drain back into the tank during pump removal. This was all performed in a highly radioactive and chemically hazardous environment, inaccessible to personnel, so most operations were required to be performed at a safe distance, either with robotics or remotely operable tooling.”
The team spent 10 months on pump removal design, 10 months in planning and fabrication and four months in the field—with one day for the operation. “The challenge was truly in the planning,” Griffin says. “We planned an execution strategy that ensured safety and success with multiple layers of contingency and robust equipment that made field work significantly easier and safe.”
The complex operation—using high-pressure water cleaning jets during extraction and extensive offsite mock-up testing—sets a template for repeatable methods to safely extract other heavily contaminated legacy equipment across the Hanford site. There were no contamination issues during the removal.
May credits the mockup training for refining the order of work and optimizing communication. “Integrating all the equipment into a complete mockup allowed us to validate that everything worked seamlessly as a cohesive unit ... to build confidence in [field crew] performance,” he says.
The Grouting Controversy
The at-capacity double-shell tanks were a key driver of a new agreement between DOE and the Washington Dept. of Ecology and U.S. Environmental Protection Agency, both Hanford site cleanup regulators, to also allow some wastes to be stabilized through grouting, without vitrification. The pact, reached last year, gained final regulatory approvals in July.
The grouting process turns waste into cement for commercial disposal outside of Washington, but has been controversial, with disputes between site managers, state regulators and environmental advocates over its efficiency in waste disposal, cost impacts and possible transportation risks compared to vitrification.
Hanford officials cite needed cost and time savings, particularly for wastes located farther from the treatment plant and also for secondary waste produced in vitrification—particularly with hiccups still in plant operation, Tim Walsh, DOE assistant secretary for environmental management, wrote to a state official. DOE said it intends to ease its backlog of waste ready for treatment by increasing the pretreatment rate to 300,000 gallons per month.
““Glass and grout need to operate in parallel. The focus is the outcome: treat more waste and complete the mission faster,” says Cerise Peck, DOE Hanford field office spokesperson. “Installing retrieval equipment and constructing pretreatment equipment will be the key steps."
The new agreement will allow low-level wastes from 22 specific tanks to be grouted and shipped out of state. Hanford Tank Waste Operations and Closure announced three subcontracts earlier this month for grouting disposal and other potential services to commercial firms Perma-Fix, EnergySolutions and Waste Control Specialists.
DOE also seeks to further expand waste grouting, and seeks public comment until Oct. 9 on two state permit modifications. "Every completed retrieval reduces the risk in the single-shell tanks and positions more waste for treatment through our dual glass-plus-grout strategy, allowing us to safely increase the pace of progress,” says Ray Geimer, DOE Hanford field office manager.
In a May report, the U.S. Government Accountability Office estimated that grouting at Hanford for about 24 million gallons of waste, which could include construction of a new facility would cost between $480 million and $1 billion, excluding transportation and disposal. Those could add between $12 million and $72 million to the cost
“This agreement has led to historic progress,” says Casey Sixkiller, state ecology department manager. But he remains concerned that the proposal to expand grouting "would divert taxpayer and staff resources away from other priority work and not result in any additional tank waste being treated,” he told DOE officials in May