A $17 billion federal facility for treating and immobilizing radioactive waste has hit a slew of construction milestones in recent months. The Hanford Vit Plant, in Washington state, is now on track to begin “glassifying” low-activity nuclear waste as soon as 2022, a year ahead of a court-mandated deadline, officials say.
Still, an air of uncertainty surrounds the project. The U.S. Department of Energy (DOE) has proposed reclassifying some of the nation’s radioactive waste as less dangerous, and it's unclear how that could affect the Hanford facility's long-term prospects.
Hanford houses about 212 million liters of high-level waste, the leftovers of the U.S. nuclear weapons program. Built in 1943, the sprawling 1,518-square-kilometer complex produced plutonium for more than 60,000 nuclear weapons, including the atomic bomb that detonated over Nagasaki, Japan, forcing an end to World War II. The remaining radioactive sludge is now stored in dozens of aging, leaky, underground tanks near the Columbia River.
After decades of discussions, federal and state officials agreed to vitrify the nuclear waste to keep it from further contaminating the soil and groundwater. Construction on the Hanford Vit Plant, known formally as the Waste Treatment and Immobilization Plant, began in 2002.
Overlooking the Low-Activity Waste Facility melter bays. The melters will heat radioactive and chemical wastes and glass-forming materials to 2,100 degrees Fahrenheit to create solid glass blocks for long-term storage.Photo: Bechtel National
As planned, technicians will mix the waste with glass-forming materials to create molten glass, which they’ll pour into stainless steel containers to cool and harden. About 90 percent of the tank waste is considered “low-activity.” It’s the waste that remains after the DOE drew off as much radioactivity as was technically and economically practical from the stream. Once vitrified, this portion could be buried at a Hanford landfill. The other 10 percent of tank waste, containing that highly radioactive material that was drawn off, is considered too dangerous to store on site and thus must be vitrified and stored in a deep geologic repository such as the long-delayed Yucca Mountain site.
At least eight technical design issues have delayed the project over the years, including hydrogen accumulating in piping and ancillary vessels, and challenges associated with treatment systems and ventilation for managing gases, like radon, that are produced as the radioactive waste material breaks down. The DOE’s Office of River Protection, which oversees the project, says all but one of the issues—erosion and corrosion in piping and vessels—have been resolved. The Defense Nuclear Facilities Safety Board is reviewing a proposed method for overcoming for that hurdle.
When finished, the Vit Plant will feature 56 buildings and systems, including: electric power distribution that could light up 2,250 houses; a compressed air system that could fill the Goodyear blimp in three minutes; and a chilled water system capable of air conditioning 23,500 houses.
About half of the systems have completed their respective startup and testing phases and have transitioned into the commissioning phase, the DOE says. The Analytical Laboratory, one of four main buildings, now has permanent power turned on. It will manage some 3,000 samples of low-activity vitrified waste each year to ensure that the radioactive material meets regulatory requirements.
Another 24 buildings are in the startup phase, including the Anhydrous Ammonia and Glass Former Storage facilities and the Chiller Compressor and Steam Plant buildings. Five more buildings are nearing turnover from construction to startup, according to Bechtel National, the project’s prime contractor.
“We continue to make significant progress toward completing portions of the Vit Plant for the direct feed low-activity waste approach,” says Staci West, a spokesperson for Bechtel. “We are bringing major utility systems online as the Vit Plant continues the transition from construction to startup and commissioning in support of treating low-activity tank waste as soon as 2022.”
However, higher-level waste has a longer timeline. Separate pretreatment and vitrification facilities aren’t slated for commissioning until 2033. All parts of the Vit Plant are legally required to begin fully operating by 2036, under a consent decree between Washington, Oregon, and the federal government.
The DOE hasn't said whether, or how, its proposal to reclassify nuclear waste would affect existing plans at Hanford if adopted. The agency is not making any decisions on the classification or disposal of any particular waste stream at this time, a DOE official said by email.
But to make sense of an agency’s plans, it’s usually helpful to look at its dollars. The Energy Department recently raised its cost projections for all U.S. nuclear waste cleanup to $494 billion—a jump of more than $100 billion from previous estimates. “The increase is primarily due to updated estimates for the [Vit Plant] construction, operating costs, tank farm retrieval and closure costs at the Hanford site,” the DOE said in a December financial report.
Though current law defines high-level radioactive waste as the sludge that results from processing highly radioactive nuclear fuel, the DOE is considering slapping a new, potentially less expensive label on it if it can meet the radioactive concentration limits for Class C low-level radioactive waste.
Reclassifying nuclear waste would allow the federal government to sidestep decades of cleanup work, saving it billions of dollars. The relabeling might even enable the DOE to bypass costly vitrification and instead contain tank waste by covering it with concrete-like grout, as the agency does at other decommissioned nuclear sites.
But officials and citizens in Washington and neighboring Oregon have long opposed this method for Hanford, citing the risk of long-term soil and groundwater contamination and the challenges of moving and storing voluminous grout blocks. Earlier federal studies found that grout “actually performed the worst of all the supplemental treatment options considered.” (A 2017 report to Congress, however, suggested both vitrification and grout could effectively treat Hanford's low-activity waste.)
On 7 January, Washington Gov. Jay Inslee and state regulators expressed their “intense discomfort” with the reclassification proposal in a letter to DOE, says Alex Smith, the nuclear waste program manager for Washington’s Department of Ecology.
She says officials are concerned that reclassifying waste will result in more dangerous materials being left behind in underground tanks. Even if the Hanford Vit Plant is completed as planned, they worry that DOE would decide to stop operating the vitrification units.
“They’ve invested billions of dollars into these facilities, and if they were to change course on what constitutes ‘high-level waste’ and how it should be treated...it’s a huge concern for taxpayer dollars,” Smith says.
The DOE received thousands of public comments to its proposal in recent months, and officials say they are carefully reviewing and considering all input.The agency remains obligated to meet milestones for building and commissioning the Vit Plant under the consent decree.